Glossary of terms
The placenta and associated membranes passed from the uterus after birth of the child. The placenta usually follows shortly after the baby. However, if it does not come on its own the doctor may have to remove it by other means, as complications may arise if it is not expelled. The foetal membranes - the chorion is the outer one and the amnion is the inner one - envelope the embryo and contain the amniotic fluid.
Alpha-fetoprotein screen (AFP)
A plasma protein normally produced by the foetus' liver. AFP eventually finds its way into the mother's blood and the amniotic fluid. When too much or too little AFP enters the mother's blood stream it can be a sign of foetal problems, such as birth defects. High AFP levels in the mother's blood indicates an increased risk of foetal spina bifida, anencephaly, or other malformations. Low AFP levels are associated with an increased risk of Down syndrome (trisomy 21) and other chromosomal problems. Measuring the AFP level is not sufficiently accurate in screening for Downs- AFP testing should be combined with other tests. Don't assume your child has Down syndrome or spina bifida just because you had an abnormal AFP test result. The AFP test assesses risk, it does not diagnose disease. Unfortunately, many abnormal test results are falsely abnormal and do not reflect a problem with the foetus or mother. If the AFP test is abnormal, additional testing should be performed.
Sometimes called an 'amnio', this minor surgical diagnostic test allows the doctor to obtain a sample of the amniotic fluid. The amniotic fluid is then analysed to look for genetic characteristics of the baby or to check on the maturity of the unborn baby’s lungs. The amniocentesis is a common way to obtain material for genetic and other testing of the baby. The doctor inserts a long, thin, hollow needle through the mother's abdomen into the uterus and amniotic fluid. Usually the doctor uses ultrasound imaging to guide the needle. The small amount of fluid removed should not affect the baby. The risk of complications from the procedure is low, but, as with any procedure, complications can occur. Be sure to consult with your doctor before the procedure is performed.
Amniocentesis helps the doctor estimate the baby's lung maturity. Because babies often 'breathe' amniotic fluid in and out of their lungs inside the womb, the amniotic fluid is chemically similar to the fluid within their lungs. As their lungs mature, the chemical composition changes. These changes can be measured from the amniotic fluid and used to estimate the maturity of the lungs.
The thin, transparent inner membrane (the chorion is the outer layer) that constitutes the amniotic membranes. These membranes contain the amniotic fluid and form a protective layer for the baby insulating him/her from bacteria in the vagina. Rupture of this sac exposes the child to bacteria in the vagina and increases the risk of infection if the infant is not delivered within about 18 hours. Labour usually starts shortly after or before rupture of the amniotic membranes.
Amniotic fluid is fluid inside the membrane that forms a sac around the embryo and later the foetus. The foetus and the placenta produce the amniotic fluid. This buoyant fluid helps the foetus grow uniformly, helps the bones and muscles develop, and allows the baby to move within the uterus. Babies breathe this fluid in and out of their lungs in the womb helping the lungs to grow as well. It also keeps the amnion (membrane) from sticking to the foetus.
Having too little or too much amniotic fluid can signal a problem with the foetus or the mother. A mild decrease in amniotic fluid is common late in pregnancy. Too much amniotic fluid may cause the uterus to enlarge, which may result in premature labour. Excess fluid occurs in maternal diabetes, twins and some other conditions. Foetal problems that may also result in excess fluid are esophageal atresia (blockage of the esophageus that prevents effective swallowing) which prevents the amniotic fluid from passing to the stomach and intestines for absorption.
Amniotomy - Intentional rupturing of the amniotic sac to hasten or induce labour. This procedure is also done to check for meconium or to allow the doctor to use an internal foetal monitor. Although an amniotomy can speed up labour, its disadvantages are that it can rarely lead to umbilical cord compression, and it eliminates the barrier that protects the foetus from bacteria in the birth canal. Some doctors frequently perform an amniotomy and some do not.
Refers to any medication that relieves pain while allowing the patient to remain conscious.
Birth defect characterised by failure of the brain and skull to form properly. Parts of the brain and the skull may be missing. This is one of several neural tube defects (NTDs). The neural tube is an embryonic structure in the developing foetus that forms the spinal cord and brain. Anencephaly occurs when the upper end of the neural tube (the rostral neuropore) fails to close in the embryo's fourth week of life. This is a fatal malformation and these children usually die within a few days of delivery. The risk of anencephaly and other NTD's can be reduced by taking appropriate amounts of folic acid before conception and throughout pregnancy.
Means in front of, usually with reference to the front part of the body. Often used in association with the term'anterior presentation' or 'occiput anterior' (OA). Usually, babies are born with the back of the head or occiput pointed up or slightly to the left or right side. It is as if the child was looking at the floor during emergence from the birth canal. This is the best position in most cases since it allows the child to negotiate more easily the turns required to get through the mother's pelvis and birth canal. If the baby presents in the birth canal with the occiput anterior and to the left it is called an LOA (left occiput anterior) presentation. If the occiput is anterior and to the right, it is called ROA (right occiput anterior).
A numerical summary of a newborn's condition at birth based on the five signs noted in the table. The score is measured at 1 and 5 minutes. Additional measurements are made every five minutes thereafter if the score is <7 at five minutes until the score reaches 7 or greater. Prematurely born infants generally have lower scores than full term infants. The Apgar score does not predict future development with accuracy. The score was developed by Virginia Apgar and represents a rough estimate of the condition of the infant at birth.
|Activity - Muscle Tone
||Arms and Legs Flexed
||Below 100 bpm
||Above 100 bpm
||Sneeze, cough, pulls
|Appearance - Skin color
||Blue-grey, pale all
|Normal, except for
|Normal over entire
Some women have labour pains that are concentrated in their back. This is more common when the baby is presenting in the birth canal with the occiput posterior (OP) with the baby looking up rather than down as in the occiput anterior (OA) position.
Yellow chemical that is a normal waste product from the breakdown of haemoglobin and other similar body components. The placenta clears bilirubin from the foetus' blood, but after delivery this task belongs to the infant. It usually takes a week or more for the newborn's liver to adjust to its new work load. When bilirubin accumulates, it makes the skin and eyes look yellow, a condition called jaundice. A little jaundice can be expected in all newborns. If the jaundice is higher than usual, it can usually be treated with phototherapy (special lights). If the level of bilirubin gets extremely high, brain injury is a risk. With modern treatment techniques such as phototherapy, such dangers rarely occur. Phototherapy is so effective in helping the liver excrete bilirubin that elevated levels are rarely a problem. Prematurely born infants may have elevated levels of bilirubin for several weeks.
A series of measurements made to evaluate the foetus' condition before delivery. The biophysical profile is similar to the Apgar system, but performed before delivery. Ultrasound observations are made for at least 30 minutes. The score is based on the findings in the table below.
|Foetal breathing movements
||The presence of at least 30 sec of sustained foetal breathing movements in 30 min of observation.
||Less than 30 sec of foetal breathing movements in 30 min.
||Three or more gross body movements in 30 min of observation; simultaneous limb and trunk movements.
||Two or less gross body movements in 30 min of observation.
||At least one episode of motion of a limb from position of flexion to extension and rapid return to flexion.
||Foetus in position of semi- or full-limb extension with no return or slow return to flexion with movement; absence of foetal movement counted as absent tone.
||Two or more foetal heart rate accelerations of at least 15 beats/min and lasting at least 15 sec and associated with foetal movement in 20 min.
||No acceleration or less than two accretions of foetal heart rate in 20 min of observation.
|Qualitative Amniotic fluid volume
||Pocket of amniotic fluid that measures at least 1 cm in two perpendicular planes.
||Largest pocket of amniotic fluid measures <1 cm in two perpendicular planes.
The tunnel comprised of the vagina and cervix, through which the infant must pass from the uterus during birth.
As the cervix dilates, blood and the cervical mucous plug (from the cervical canal) pass from the vagina. The bloody show is a classic indicator of beginning or progressing labour.
An abnormally low heart rate. When referring to the foetal heart rate (FHR) tracing in labour, abnormally low heart rates can signal problems with the foetus before delivery. The FHR is often monitored for abnormalities of the heart rate. Foetal bradycardia episodes are sometimes called FHR decelerations. Some types of FHR decelerations are common during labour. Others suggest foetal stress and demand further evaluation or intervention. Sometimes the FHR not only dips down, it stays down and does not return to its usual level. This is an ominous situation that demands immediate delivery. FHR decelerations or bradycardia episodes come in three types.
- Early decelerations are normal and common. These decelerations are called early because they occur early during a uterine contraction. These FHR decelerations usually occur after labour is well established (4-7 cm of cervical dilatation). The FHR rarely goes below 100 beats per minute. The cause of these decelerations is head compression during uterine contractions.
- Late decelerations cause more concern. They are called late because they first appear at or after the peak of the uterine contraction. The FHR improves only after the contraction has stopped. These FHR decelerations may be mild or severe based on how low the FHR goes and how long it takes for the FHR to recover. It is thought to be caused by reduced blood flow to the uterus and placenta during a contraction.
- Variable decelerations are a common type of FHR deceleration in labour and are caused by umbilical cord compression. Up to 80% of foetuses will have variable decelerations during labour. The significance of the these decelerations depends on how low the heart rate drops and how long the episode lasts. When referring to a newborn baby bradycardia is usually associated with apnoea or cessation of breathing. Apnoea and bradycardia spells are most common in prematurely born infants. During these spells the infant will stop breathing for at least 15 seconds and the heart rate will start to slow. Gentle touching or other stimulation almost always restarts the breathing and increases the heart rate. Medications (theophylline or caffeine) are often used to treat these spells in newborn babies. Apnoea of prematurity does not cause sudden infant death syndrome (SIDS). However, prematurely born babies are at greater risk for SIDS, just because they are prematurely born. The exact reasons why premature babies have a higher risk of SIDS is not known.
Periodic contractions of the uterus that do not represent true labour. These contractions may begin as early as the first trimester, are irregular, usually painless, and of low intensity. They can be confused with labour. Toward the end of the third trimester, the contractions become more frequent and intense.
When babies are aligned in the uterus to come out buttocks first, as opposed to head first--the way most babies come out of the uterus --it is called a breech presentation. The head is the largest part of a full term baby's body. Therefore, delivery of the buttocks first may not adequately open up the birth canal enough for the head to pass through. The head may then get stuck in the birth canal, leaving the infant and mother in a precarious situation. Most babies with a breech presentation are delivered by caesarean section. On occasion the infant can be turned around so that he is lined up to come out head first.
Delivery of the baby through an incision in the abdominal and uterine walls when delivery through the birth canal is impossible or dangerous. This procedure was performed as early as 715 BC and can be lifesaving for both the infant and the mother in certain situations. However, elective caesarean sections (those scheduled in advance and performed before a woman goes into labour) when performed before term are a significant cause of medical problems in the baby. If a caesarean section is performed before the infant's lungs have completely matured, the infant may have serious respiratory problems. Elective caesarean sections would normally be performed only if there is good evidence that foetus has mature lungs. Women should be evaluated using methods to make sure that the foetus' lungs are mature. The criteria are as follows:
- Foetal heart tones should have been documented for 20 weeks by non-electronic fetoscope or for 30 weeks by Doppler.
- It has been 36 weeks since a positive serum or urine chorionic gonadotropin pregnancy test was performed by a reliable laboratory.
- An ultrasound measurement of the crown-rump length, obtained at 6-11 weeks, supports a gestational age of at least 39 weeks.
- An ultrasound, obtained at 12-20 weeks confirms the gestational age of at least 39 weeks determined by clinical history and physical examination.
An alternative method to assure foetal lung maturity is toperform an amniocentesis and measure chemicals in the amniotic fluid. The concentrations of these chemicals are a good reflection of lung maturity status.
Caput succedaneum (caput)
A spongy swelling and accumulation of fluid in scalp tissues of infants born vaginally. This occurs because the baby's head, in normal presentation, is under much pressure in the birth canal, This pressure on the skin of the scalp causes accumulation of soft tissue fluid. Although it may look serious, it usually disappears within a few days.
The most common reason for doing a caesarean section. Sometimes the infant's head is larger than the mother's pelvis, through which the head must pass in a vaginal delivery. Therefore, the safest way to deliver the infant is to do so by caesarean section. There are several ways to estimate foetal size and pelvic size. Physical exam and ultrasound are very useful in evaluating cephalopelvic disproportion.
This usually refers to a prostaglandin medication that is prepared in a gel-like material. It is placed on the cervix to hasten cervical dilatation in preparation for delivery.
Inability of the cervix to remain closed during pregnancy. The properly functioning cervix will be tightly closed until labour to keep the foetus safely inside the uterus. Some women have a cervix that does not stay closed and opens up in the second or early third trimester. This can result in miscarriage of the pregnancy or premature delivery of the baby. To avoid premature delivery with an incompetent uterus the cervix may be stitched up or the mother may be confined to bed. The reason for many of these cases is not known. However women who were exposed to diethylstilbestrol (DES) as a foetus or those who have had removal or cauterisation of cervical tissue may be at increased risk for this.
Inflammation of the cervix.
The lower portion of the uterus. The cervix is the part of the uterus that keeps the foetus from falling out of the uterus. During labour, the cervix thins and dilates to permit passage of the infant out of the uterus and into the vagina.
Infection, of the chorionic and amniotic membranes caused by bacteria. These membranes enclose the amniotic fluid and when infection is present in the membranes, the mother and foetus are at increased risk for severe infection. When chorioamnionitis occurs, delivery of the foetus should be undertaken without delay. The infection is very difficult to treat without delivery of the foetus. Chorioamnionitis can also cause premature labour.
The outermost layer of the two foetal membranes, which envelope the growing foetus and serves as a protective barrier to the foetus against infection.
Chorionic villus sampling
A prenatal diagnostic test, done at 8-10 weeks of pregnancy to asses the foetus' chromosomes. The advantage of this test over amniocentesis is that (CVS) can be done earlier in gestation than the amniocentesis. However, the risks to the foetus are greater than with amniocentesis. Chorionic villi are a part of the placenta but contain foetal tissue. A needle is inserted into the chorionic villi of the placenta and a small amount of tissue is removed and sent for analysis. The placenta can be approached either through the cervix or through the mother's abdominal wall.
Also called chromosomal malformations, anomalies, or defects. This refers to abnormalities in the number or organisation of chromosomes. A common example is trisomy 21 or Down syndrome, in which there is an extra chromosome number 21. This extra chromosome results in a constellation of abnormalities that is usually recognizable at birth and consistent from one patient with Down syndrome to another.
Removal of the prepuce or foreskin covering the penis. There has been a lot of controversy about this procedure in the past few years. Some believe that it is medically beneficial while others disagree. There are repeated studies showing that urinary tract infections are less common in circumcised boys. However, urinary tract infections are relatively rare in boys anyway. There have also been studies of sexual function in circumcised and uncircumcised males with very few differences found between the two groups. In some populations, circumcision reduces the risk of contracting AIDS. Penile cancer (also a very rare disease) is also less common among circumcised men.
Almost always refers to the contracting of the muscles of the uterus during labour. The uterus contracts in an effort to expel the foetus into and out of the birth canal. Contractions are usually a sign of labour, although they can occur before labour, see Braxton Hicks contractions.
Contraction stress test
A test of uteroplacental function. Uterine contractions are initiated with Pitocin and the foetal response to the contractions is analysed as a measure of foetal well being.
Cord blood banking
Storage of blood from the umbilical cord. Blood in the umbilical cord is rich in blood cells that are able to replenish the bone marrow. Freezing cord blood cells immediately after delivery preserves these cells should the baby need a bone marrow transplant in the future. It is not now clear that this should be done or how useful these cord blood specimens will be in the future. The potential usefulness of cord blood is the object of much ongoing research.
Squeezing of the umbilical cord during pregnancy, labour or delivery. Pressure on the umbilical cord reduces blood flow from the placenta to the foetus. If prolonged pressure is applied, it can produce a dangerously low level of oxygen in the foetus.
The stage in childbirth when the top of the infant's head becomes visible at the vaginal opening.
The room where the delivery occurs. In the past pregnant women routinely laboured in one room and then were moved to a delivery room where the baby was actually delivered. Following delivery, the mother would then be moved to a recovery room. To prevent these cumbersome moves, many hospitals have now changed to a combination labour, delivery and recovery room (called the LDRP). This prevents having to move the mother to another room at the height of labour pains, just before delivery.
Meperidine hydrochloride (Demerol), either alone or in combination with promethazine hydrochloride (Phenergan), has the advantage of a history of extensive use in labour. Common dosing is 50 to 100 mg of meperidine and 25 to 50 mg of promethazine IM every 3 to 4 hours. Both medications can be given IV, but at reduced dosages of 25 to 50 mg of meperidine (diluted to 10 mg/mL) and 25 mg of promethazine. Since metabolic by-products of meperidine may have half-lives of 8 to 21 hours and will accumulate in patients with renal impairment and in their premature foetuses and neonates, the risk-benefit ratio requires re-evaluation before repeated dosing. The manufacturers recommend giving no more than 100 mg of promethazine during 24 hours of labour.
A synthetic, non-steroidal oestrogen that was prescribed to many women up until the early 1970s. It was thought to prevent or treat problems with pregnancy. However, female foetuses who were exposed to DES developed serious problems in their reproductive organs when they became adults. About 1/4th of exposed women develop anatomical problems with their cervix or vagina. Examples of these are underdeveloped cervix, small uterine cavities and abnormal fallopian tubes. These women are also more likely to have ectopic pregnancy, preterm labour, miscarriage and incompetent cervix. Women whose mothers took DES during pregnancy should mention this fact to their obstetrician so that potential problems can be identified and treated.
Opening up, enlargement of a tubular structure. This usually refers to the cervical dilation that occurs during labour. The opening of the cervix must go from essentially 0 centimetres to about 10 centimetres, the usual size required for the baby to pass through the cervix, which forms part of the birth canal. The first stage of labour is that part of labour during which the cervix dilates up to 10 cm or is completely dilated. This usually takes several hours and is shorter with subsequent pregnancies.
A special form of ultrasound that uses sound waves to measure the velocity of blood flow. Doppler ultrasound can be used to listen to the foetal heart beat, examine the foetal heart for defects, and estimate placental blood flow.
A condition that has a specific set of characteristics found in children who have an extra number 21 chromosome. Another name for this condition is trisomy 21. Characteristic findings are widely spaced first and second toes, a single hand (simian) crease, short fingers, a fold of tissue (epicanthal fold) across the inner aspect of the eye (near the nose), eyes that slant upward, decreased muscle tone, flattened back portion of the head, and a protruding tongue. The only way to make the diagnosis with certainty is to perform a chromosomal analysis either before birth (chorionic villus sampling or amniocentesis) or after birth (blood or tissue chromosomal analysis). The range of outcomes for these children is quite broad and many function quite well, although very few have normal intelligence.
The risk of a healthy woman having a child with Down's syndrome increases with maternal age, as follows:.
Age Risk of Down’s syndrome
- 25 years 1 in 1300
- 30 years 1 in 900
- 35 years 1 in 350
- 40 years 1 in 100
- 45 years 1 in 25
- 49 years 1 in 12
Literally, it means difficult labour and practically means abnormally slow progress of labour. The word comes from the Greek 'dys' meaning 'difficult, painful, disordered, abnormal' and 'tokos' meaning 'birth'. Four potential factors may cause difficult labour characterised by abnormally slow progress. They may occur separately or together.
- Uterine contractions may be either too weak or too uncoordinated to open up the cervix. There may also be inadequate pushing with voluntary muscles during the second stage of labour.
- The baby may be lined up wrong to easily pass through the birth canal. Alternatively, there may be other problems with the baby that also retard passage of the baby through the birth canal.
- The maternal bony pelvis may be too narrow to allow the baby to pass through the birth canal.
- Abnormalities of the birth canal other than those of the bony pelvis may obstruct foetal descent.
The most common cause of dystocia is a small bony pelvis and/or insufficiently strong and coordinated uterine contractions.
Pregnancy in which the embryo develops outside of the uterus. Normally, conception occurs not in the uterus but in the fallopian tubes. The fertilised egg then moves down into the uterus where it should implant in the lining of the uterus. When the embryo implants anywhere else other than the uterine lining it is called an ectopic pregnancy. As the embryo grows outside of the uterus it is usually in a confined space, such as the fallopian tube. Eventually, the embryo enlarges the tube to the point of rupturing the fallopian tube, which causes haemorrhaging. This haemorrhaging can be so severe as to cause shock and death. Surgery is required to remove the misplaced, embryo. The embryo itself is usually normal and would have continued to develop normally had it implanted in the uterus, rather than the fallopian tube or other abnormal location.
Losing a child through an ectopic pregnancy can be very emotionally traumatising. A woman who has lost a pregnancy due to ectopic location needs the same support as women who have lost pregnancies through miscarriage and other causes.
Ectopic (in the wrong place) pregnancy is the leading cause of maternal mortality in the first trimester and is a true emergency. Fortunately, the incidence remains very low. Symptoms of ectopic pregnancy include abdominal pain, missing a normal period, intermittent or scanty vaginal bleeding, shoulder pain, weakness, dizziness, and fainting. Significant abdominal pain (anywhere in the abdomen) in the first trimester should be reported to your doctor.
Thinning of the cervix that occurs in preparation for childbirth. The cervical canal shortens from 2 cm to paper thin edges and the canal itself disappears. Only the external opening of the uterus remains of what was the cervix. The edges of the internal opening of the cervix are drawn upward several centimetres to become a part of the lower uterine segment. When the cervix becomes as thin as the adjacent lower uterine segment, it is considered to be completely effaced.
Electronic foetal monitor
An electronic device that is used to monitor the heart rate of the foetus before delivery. The electronic foetal monitor is usually used in labour and can identify foetal problems before delivery. There is some evidence that monitoring the foetal heart rate electronically may increase the rate of caesarean delivery. Most obstetricians believe that it identifies serious foetal problems earlier than other methods, thus improving outcome. Another method for monitoring the foetus' health during labour is listening to the foetal heart beat with a special foetal stethoscope or Doppler ultrasound device at regular intervals. There are two types of foetal monitors:
- External, which are attached to the mother's abdomen.
- Internal, which attach to the infant's scalp inside the uterus.
Refers to the point in labour/delivery at which the baby's head, or other presenting part (buttocks in a breech presentation), begins to descend through (engage) the pelvic canal.
The epidural is situated over the dura matter. The dura is a tough, fibrous, whitish membrane; the outermost of the 3 membranes covering the brain and spinal cord. The extradural is located outside of the dura matter.
An anaesthetic technique that reduces pain during childbirth without altering the mother's level of consciousness. This type of regional anaesthesia is often given during labour to relieve the pain of contractions and delivery. A needle is inserted through the skin of the back into the epidural space. Anaesthetic is then injected around the spinal cord anaesthetising the nerves of the lower part of the body. A well-placed epidural block provides excellent pain relief. A potential disadvantage is a reduction in a woman's ability to push the baby out of the birth canal. Some people feel that the use of an epidural block may increase the likelihood of a caesarean section. The epidural block may also lower a woman's blood pressure, affecting blood flow to the baby. However, in the hands of alert, experienced personnel, the risks of an epidural are low.
A minor surgical procedure which widens the birth canal by cutting the introitus (vaginal opening). Episiotomy is performed to prevent the jagged, less controlled tearing of the introital tissue during the stretching associated with delivery. The routine use of an episiotomy may cause more problems than it solves and has been linked to increased rectal tearing. It is a painful procedure that may predispose to infections and other complications. An episiotomy may be very helpful when forceps or vacuum extraction are used and with breech presentations. Talk to your doctor about whether you might need one. The use of episiotomies has decreased in the past few years.
External cephalic version
Turning the baby so that the head is pointed down toward the pelvic inlet. In most pregnancies, babies orient themselves with the head down toward the pelvis in preparation for labour and delivery by about the 34th week. If the baby is oriented with the head up or lying with the back toward the pelvis, labour is more complicated and a caesarean delivery is more likely. Your doctor may try to turn the baby before delivery- this is called an external version. The doctor will try to turn the baby so that the head is down, pointing toward the pelvis. This is done with pressure on the baby applied through the mother's abdomen. External cephalic version reduces the necessity of a caesarean section, but is not indicated in every case of breech presentation. Ask your doctor more about version to see if this procedure is appropriate for you. There are both risks and benefits from this procedure.
Use of a special, fibre optic, tubular telescope to look at the foetus while it is still in the mother's uterus. Use of this scope requires a tiny incision in the mother's abdominal wall so that the telescope can be passed into the uterus to directly view the foetus. Technically, listening to the foetal heart rate with a fetoscope, a special type of stethoscope is also fetoscopy.
Problems with the unborn child during labour. Sometimes during labour and delivery the foetus may not get enough oxygen from the placenta and may become 'distressed'. When this happens, the foetal heart rate may show patterns consistent with oxygen deprivation. These patterns can been seen on the foetal heart rate monitor. They alert the obstetrician that further investigation or intervention is needed to assure the foetus' well-being.
Monitoring of the baby before birth. This usually refers to monitoring of the foetal heart beat. There are two ways to do this. Before the mother's membranes have ruptured (water has broken) a belt containing a receiver similar to an ultrasound can be strapped to her abdomen and used to monitor the foetal heart rate and uterine contractions. After the membranes have ruptured and the cervix has dilated, an internal monitor can be attached directly to the baby's scalp. There are other tests that can be used to monitor the foetus during and before labour such as ultrasound, scalp pH measurements, and others.
The part of the foetus that enters the birth canal first. When the head enters the birth canal it is called a vertex presentation. When the buttocks present first it is called a breech presentation. There are several methods used to diagnose foetal presentation: abdominal palpitation, vaginal examination, locating the foetal heart beat on the abdomen, and ultrasound scans. At or near term 96% of babies are in a vertex position, 3.5% are in a breech presentation, 0.3% in a face presentation, and 0.4% are in a shoulder presentation. About 2/3 of vertex presenting babies are in a left occiput anterior (See Anterior.) and 1/3 are in a right occiput anterior position. Up to 14% of babies are in a breech presentation until the 29th-32nd week of gestation. Many of these babies change to a vertex presentation birth.
The name given to the embryo after the 8th week. Technically this name should be used until the baby is completely outside of the mother's body.
Soft spots found between the cranial bones of the newborn’s skull. There are two fontanelles that are usually examined in the newborn period, the anterior and the posterior fontanelles.
Presentation with the feet entering the birth canal ahead of any other part of the body. This may occur with two feet (double footling) or a single foot (single footling). Most often one leg is extended while the other is flexed at the knee. It is usually safer to deliver this kind of baby by a Caesarean section early in labour or before labour begins rather than vaginally. If a footling breech is delivered vaginally, there is a risk that the head may not easily through the birth canal.
A delivery in which forceps are used to help assist the baby from the birth canal. Forceps are a two-bladed instrument that could be compared to a pair of kitchen tongs in design. Forceps have the additional feature that the two blades are easily taken apart to facilitate placement on the baby within the birth canal. After placing the two blades on the baby's head, the doctor reconnects the two blades and then uses the forceps to apply traction to the infant, assisting delivery. The forceps are not sharp, but they firmly grasp the baby's head. Forceps may be used for several different reasons: to shorten the second stage of labour, end an abnormally long second stage, when the foetal heart rate suggests problems, when the mother suffers from cardiac disease, or whenever the health of the mother and baby are declining and a speedy delivery is required. Although once used often, they are almost never used now.
Baby’s age in weeks from the first day of the mother’s last menstrual period before delivery. The duration of a pregnancy is measured by gestational age. Gestational age is basically a measure of the length of time that a baby spends in the womb. It is generally calculated as the time from the first day of the last menstrual period to the day of birth. Conception occurs on about day 14 after the first day of the last menstrual period. However, this date is not usually known. The first day of the last menstrual period usually is known. Therefore the beginning date for the pregnancy is the first day of the last menstrual period.
A normal gestation lasts 40 weeks or 280 days. If delivery occurs before 37 weeks gestation, the baby is considered prematurely born. By this definition, about 11% of all babies are born prematurely. Irregular menstrual periods or first trimester vaginal bleeding can confuse gestational age estimates. To improve the accuracy of gestational age estimates, many doctors use an ultrasound examination before about 20 weeks gestation. Ultrasound findings help your doctor confirm or correct the gestational age estimate.
An abnormal bulging or protrusion of tissue or an organ through an abnormal opening. The most common type of hernia is an inguinal hernia. It is seen more often in boys, but it can be present occasionally in girls. The testes develop inside the abdomen and migrate through the inguinal canal and into the scrotum. The inguinal canal is the passageway from the abdomen into the scrotum and is bounded by membranes and muscle. When the inguinal canal does not completely close or re-opens, intestine can travel down the passageway and a hernia develops.
In most full-term babies the inguinal canal seals over before birth. In prematurely born infants, the canal is opened by the pressure of the baby crying and the increased abdominal pressure associated with feedings and life outside the uterus. The incidence of hernias is about 15 percent among prematurely born infants. It may be higher in those who are extremely premature.
The only way to correct a hernia is to surgically repair it. The anaesthesia risks of the procedure are lessened if repair is delayed until about five months of age; however, hernia repairs are often performed in infants at much younger ages, if necessary, without complications. For some infants a combination of a local and spinal anaesthetic can be used instead of general anaesthesia. This combination of anaesthetics reduces the risk of apnoea following anaesthesia and surgery.
Incubator (plastic box that is heated and sometimes humidified). It provides a warm, protected environment for premature babies who are often not able to maintain their own temperature because of their small size and body mass.
Painless cervical dilatation in the 2nd trimester often followed by premature delivery of the foetus. This can sometimes be diagnosed early on with the use of an ultrasound. The only real treatment is a surgical procedure called cerclage, which reinforces the cervix with sutures. An alternative to surgery is bed rest, but this is not always effective. Possible complications to cerclage are bleeding, contractions, and ruptured membranes, but if done by the 18th week these risks are decreased. The success rate is about 85-90%. If an incompetent cervix is not properly treated it will cause problems with each subsequent pregnancy.
If labour has not started at an appropriate time or if there are maternal indications for delivery before labour starts naturally, medications may be used to initiate labour. Prostaglandin gel and oxytocin (Pitocin®) are the most common medications. Rupture of the amniotic membranes may also hasten the onset of active labour.
IUPC (intrauterine pressure catheter)
A catheter inserted into the uterus during labour to measure the actual pressure within the uterus. These measurements are important in measuring the frequency and intensity of uterine contractions. The foetal heart rate is usually measured simultaneously. The combination of these measurements facilitates the evaluation of labour and foetal well-being.
The oldest, most common technique for reducing the stress and pain of labour and delivery. Lamaze trains women to replace unproductive behaviour during labour and delivery, such as anger and screaming, with more productive actions, such as relaxation and deep breathing. Emphasis on relaxation and breathing make pushing more effective and less painful.
Dark green, sticky mucus normally found in infants' intestines. It is the first stool passed by the newborn. Meconium is a mixture of amniotic fluid, bile and secretions from the intestinal glands. Passage of meconium within the uterus before birth can be a sign of foetal distress. Meconium is very irritating to the lungs. If there is a possibility that an infant may have thick meconium in the lungs, the doctor inserts a tube into the trachea and suctions out the loose meconium. This tube, called an endotracheal tube, can also be used to help an infant breathe after the meconium has been removed.
Spontaneous abortion or loss of the foetus before 21 weeks of gestation. Habitual abortion is defined as the spontaneous loss of 3 or more consecutive pregnancies. Habitual or recurrent abortion is a form of infertility. Couples who have had 2 or more miscarriages (spontaneous abortions) have about a 5% chance that one member of the couple is carrying a chromosome problem that is contributing to the miscarriages. A considerable proportion of pregnancies end in miscarriage.
The creation of shape, or fashioning of an object. Usually refers to the newborn's head that is moulded by passage through the birth canal during vaginal delivery. The head takes on a pointed shape that quickly returns to normal after a few days. The brain is very plastic and tolerates this molding well.
A plug of mucus that fills the cervical canal during pregnancy. Discharge of the plug is usually followed by rupture of the membranes and progressive labour.
The process of giving birth without anaesthesia or medication to relieve pain. Natural childbirth is not possible for everyone, if you would like to experience a natural childbirth discuss this with your doctor.
The name given to a newborn infant for the first four weeks after birth.
Doctor who specialises in the care of sick newborn babies. Physicians must first become paediatricians through three years of specialty training. They then spend more years sub-specialising in the care of sick newborns.
Nubain is a potent analgesic. Its analgesic potency is essentially equivalent to that of morphine on a milligram basis. Its onset of action occurs within 2 to 3 minutes Its onset of action occurs within 2 to 3 minutes after intravenous administration, and in less than 15 minutes following subcutaneous or intramuscular injection. The plasma half-life of nalbuphine is 5 hours and in clinical studies the duration of analgesic activity has been reported to range from 3 to 6 hours.
The narcotic antagonist activity of Nubain is one-fourth as potent as nalorphine and 10 times that of pentazocine.
Specialists in paediatrics spend at least three years after medical school studying children's health problems. Many devote additional years to sub-specialise in a particular area of paediatrics such as heart, lung, or endocrine problems. Paediatricians often employ nurse practitioners or physician's assistants. These individuals work under the supervision of the paediatrician and are often an important part of a paediatric clinic.
Refers to the time period after the 28th week of gestation and ending the first week after birth. Some sources extend the perinatal period until the fourth week after birth.
An obstetrician who has sub-specialised in the care of pregnant women and unborn babies. If you have a complicated pregnancy or one at high risk of having complications, you may be referred to one of these physicians. They are often the specialists who perform the level 2 or detailed ultrasound examination.
Persistent foetal circulation
The circulation of blood in the foetus is somewhat different from that of the baby after birth. This transition from foetal to neonatal circulation is one of the major physiologic changes after delivery. Before birth, the lungs are collapsed and the blood pressure in the lungs is quite high. This results in a very low blood flow through the lungs. After delivery, the lungs expand and the blood pressure in the lungs decreases.
In some babies, although the lungs expand the blood vessels in the lungs remain constricted resulting in persistently high blood pressure in the lungs. This reduces the amount of blood that the infant can pump through the lungs. This decreased blood flow through the lungs after birth is called persistent foetal circulation because it is a persistence of the pattern of blood flow normally seen prior to birth during the foetal period.
Infections, malformations of the lung or diaphragm, and lung immaturity can all cause persistent foetal circulation. This is a very serious, although infrequent, newborn problem. Several new treatments for persistent foetal circulation have been developed in the past few years and have increased survival of infants with this problem. The more medically correct name for persistent foetal circulation is persistent pulmonary hypertension.
Synthetic formulation of a hormone, oxytocin, that stimulates uterine contractions and is used to induce labour or delivery. Pitocin® is a commonly used drug during labour.
Organ within the uterus that provides communication between mother and foetus through the umbilical cord. The placenta enables oxygen and nutrients to pass from the maternal blood to the foetus. It also eliminates carbon dioxide and waste products from the baby by passing them to the mother, who excretes them with her liver, kidneys or lungs. It is a disk shaped organ and at term weighs around 500 grams.
Abnormally deep growth of the placenta into the uterus. Placenta accreta prevents the normal placental separation from the uterus and often causes severe uterine bleeding after delivery.
Occurring after childbirth, or delivery.
Care given to a mother after she has given birth. Usually this refers to the care given before she is released from the hospital, but can extend past discharge.
Baby born three or more weeks before the due date. The length of a pregnancy is measured by gestational age. Gestational age equals the amount of time that has elapsed since the first day of the last menstrual period. A normal gestation lasts 40 weeks or 280 days. If delivery occurs before 37 weeks gestation, the baby is considered prematurely born. About 11% of all babies born in 1997 (in the USA) were born prematurely by this definition. Irregular menstrual periods or first trimester vaginal bleeding can confuse gestational age estimates. To improve the accuracy of gestational age estimates, some doctors use an ultrasound examination before about 20 weeks gestation. Ultrasound findings help your doctor to confirm or correct the gestational age estimate.
Onset of labour before 37 completed weeks of pregnancy. Tocolytic agents (medications used to inhibit labour) are widely used today to treat premature labour and permit pregnancy to proceed so that the foetus can gain in size and maturity before delivery.
Birth weight is lower when a baby is born prematurely. Babies born with a weight of less than 2500 grams are considered low birth weight babies. Generally, infants with a birth weight less than 2500 grams are premature; however, babies can be premature and still weigh more than 2500 grams at birth. They can also be born at term and weigh less than 2500 grams. There is no perfect system for categorising infants; both measurements, birth weight and gestational age, are used.
Many premature deliveries occur close to term and these infants generally do well. For example, only 1.9 percent of all infants born in 1997 were born at less than 32 weeks gestation. These infants routinely require lengthy stays in a special care nursery. These infants are also at risk for long-term problems. The risk of complications accelerates as gestational age decreases.
Positioning of the umbilical cord ahead of the baby's presenting part during labour and delivery. When this occurs, the baby's body puts pressure on the umbilical cord which is caught between the baby and the mother's birth canal. This pressure can seriously reduce or altogether stop the blood flow through the umbilical cord.
Unless the pressure is removed through either delivery of the infant or repositioning of the infant, serious problems occur. Prolapsed umbilical cord occurs more commonly with breech than with vertex presentation.
Labour which takes an abnormally long length of time. The usual length of time in labour is longer in primiparous women and varies considerably among individuals.
A class of chemicals produced by the prostate and other parts of the body that can have various and powerful effects on the body. They were first discovered in the prostate gland, hence their name. Prostaglandins are sometimes used to induce labour or soften the cervix in anticipation of inducing labour.
A male reproductive gland that produces part of the fluid in ejaculate. It surrounds the urethra and often enlarges in older men to produce urinary symptoms. Prostatic cancer commonly occurs in older men and is one of the most important cancers in males.
An incompatibility of blood types. Blood types are commonly characterised by the ABO typing system and the Rh system. An incompatibility between the mother and foetus in either of these systems can result in maternal antibodies crossing the placenta and destroying foetal red blood cells. The Rh system more often causes serious problems than the ABO system.
Individuals are either Rh-positive (red blood cells carry the Rh antigen) or Rh-negative. When a Rh-negative woman is pregnant with a Rh-positive foetus (Rh-positive inherited from the father), the mother can produce antibodies against the Rh portion of the foetal red blood cells. These antibodies attack the foetal red blood cells and destroy them. Loss of the foetal red blood cells causes elevated bilirubin, decreased red blood cell count and sometimes even heart failure in the foetus. The combination of these problems can be fatal.
There are ways to treat this problem before the baby is born. More effective than treatment is prevention of the problems. Women are exposed to Rh-positive red blood cells through a previous pregnancy, miscarriage or a mismatched blood transfusion. If a Rh-negative mother has been exposed to Rh-positive red blood cells, she should receive Rho-GAM, a special immunoglobulin that destroys the Rh-positive red blood cells before they can stimulate the woman to produce antibodies against Rh-positive cells.
An alternative rooming arrangement in postpartum units. With rooming-in the infant does not stay in the newborn nursery, but in the mother's room during her hospital stay.
Small for gestational age (SGA)
Children whose birth weights are below the 10th percentile (smaller in weight than 90 percent of other infants born at the same gestational age) are considered small for gestational age (SGA). Being small for gestational age has several other names. Some of these follow:
- Intrauterine growth retardation
- Small for dates
- Light for dates.
SGA has many causes. If your baby is SGA, your baby's doctor should search for an explanation. This is important because some problems cause reduced growth in childhood as well. The following is a partial list of factors that can contribute to an infant being SGA:
- Maternal high blood pressure [mother’s?]
- Cigarette smoking
- Maternal street drug use
- Maternal malnutrition
- Low maternal weight gain (less than 9 Kilograms)
- Mother was also SGA at birth
- Maternal chronic disease (advanced diabetes, anaemia, etc.)
- Frequent, heavy, physical work during pregnancy
- Mother younger than 20 years of age
- Racial and ethnic background
- Multiple foetuses (twins, triplets)
- Rubella, cytomegalovirus, and other infections during pregnancy
- Placental abruption (separation of the placenta from the uterine wall)
Foetal chromosome problems (Children with abnormal chromosomes seem genetically programmed to remain small and not gain weight appropriately.)
SGA babies have more problems in the newborn period than infants who are appropriately grown. Examples of these problems are low blood sugar and too many red blood cells in the blood. These problems are all treatable, but may require NICU care. SGA babies are also more likely than AGA (appropriate for gestational age) infants to be small throughout life and have delayed development. Babies whose growth slowed down later in pregnancy are more likely to catch up with their peers than those whose growth was slow throughout pregnancy.
Stadol NS is the trade name for butorphanol tartrate nasal spray. Stadol NS is a special type of prescription pain reliever used to treat moderate to severe acute pain, including the pain of a migraine attack in progress. Although it is a potent analgesic, it does not incorporate the addictive properties of many narcotic drugs. Stadol NS was designed to activate certain receptors in the brain to eliminate pain while blocking the receptors that cause euphoria. In other words, it is designed to stop the pain without causing a 'high'.
Imaging of body parts using sound waves. Ultrasound uses sound waves that are above the range of human hearing to create an image of organs within the body. Sound waves are reflected off internal body structures and back to the ultrasound machine. The reflected sound waves are analysed by computer and turned into pictures. This method of imaging results in less clear pictures than X-rays, CAT scans or MRI. However, there is no radiation risk with ultrasound and no confirmed adverse effects on the foetus or mother from diagnostic ultrasound examinations in pregnancy.
There are different types of ultrasound exams. They are differentiated by the purpose for which they are done and the level of detail obtained.
- Limited exams are focused studies used to answer specific questions about the foetus, mother, or both. This exam is often used when you go to your doctor or the hospital with an urgent problem related to your pregnancy.
- Basic exams are performed to survey for obvious malformations of the foetus and to estimate foetal age, the amount of amniotic fluid present, location of the placenta, and for other concerns. These are the kind of exams that you would likely receive in your doctor's office or in the hospital as a routine evaluation. They are typically performed at 18-20 weeks of pregnancy.
- Comprehensive exams are a more in-depth look at the foetus when there is reason to suspect something is wrong with the foetus or mother. They include a detailed examination that is often done as a response to an abnormal screening test such as the alpha-fetoprotein screen. In some areas of the country this is called a Level II or Level III ultrasound. Technical difficulties and the need to image many different areas of the foetus may extend the length of this exam to 30 or more minutes.
Ultrasound can measure foetal size, the amount of amniotic fluid, estimate foetal gestational age, identify multiple foetuses, some foetal abnormalities such as microcephaly or Down Syndrome, and locate the location of the placenta. Although an ultrasound can usually determine gender of your baby, many families do not want to know this information before delivery and some ultrasound centres have a policy of not revealing the gender.
The baby's lifeline from the mother during pregnancy. The umbilical cord is formed during the fifth week of gestation and connects the foetus' circulation with the mother's placenta. Through this vascular structure, the foetus receives nutrients such as oxygen, glucose, and protein. When the baby is born the cord is about 600 mm long and 12 mm thick.
The umbilical cord is clamped and cut shortly after birth. It will turn black within the first few days and should protrude about 25 mm or less. It will fall off within about 2-3 weeks. It is important to care for the umbilical stump to ensure proper healing. Fold daipers below the stump to expose it to air and keep it dry. Cleaning should be with a cotton swab and alcohol. The ideal time to do this is just after changing a diaper. If you notice that the skin around the stump has turned red or if the cord is oozing, call your doctor.
Hernia at the belly button. (see hernia.) The abdominal wall is formed by two sheets of muscle that run along both sides of the abdomen. In normal development, these sheets of muscle fuse together. When the fusion is incomplete or abnormal, part of the bowel can bulge through the space between the muscles at the belly button. As the infant grows, the muscle layers increase and gradually fuse, eliminating the hernia. This is one of the few hernias that often resolves on its own. Occasionally, surgical correction is required.
Also called the womb. The uterus is the organ that houses and protects the foetus during pregnancy. The uterus grows and expands with your baby's growth. Your doctor will measure this growth during prenatal visits. The uterus also helps the foetus leave the womb through contractions. It will take several weeks to months after delivery for your uterus to regain a normal shape and size following delivery.
The application of a suction cup to the head for helping deliver the infant. This technique performs a similar function as forceps and helps the baby to descend through the birth canal. The vacuum extractor has a soft plastic cup attached to a tube and suction pump. The cup is inserted into the birth canal and attached to the baby's head by suction. Increasing the suction causes a vacuum and the handle of the cup can be used to pull the baby out of the birth canal. The vacuum extractor is more gentle and less damaging to the mother's soft tissue than forceps. However, there are risks with the vacuum extraction. Excessive suction or traction can cause injury to the mother or baby. There is also a limit on the number of pulls that should be made with the suction device attached.
Delivery of the infant through the birth canal, of which the vagina is a major component. The alternative method would be an operative delivery (caesarean section).
Vaginal birth after caesarean (VBAC)
A vaginal delivery after a previous caesarean delivery. One of the most common reasons for caesarean sections is the presence of a uterine scar from a previous caesarean section. A previous uterine scar can tear or open up during a hard labour with a subsequent pregnancy. For many years it was thought that once a caesarean, always a caesarean. This is not so. If the incision from the previous caesarean section has been performed low on the uterus, the scar is often sufficiently strong to withstand labour.
The advantages of a VBAC are decreased risk of surgical complications and a shorter recovery period. However, a VBAC is not possible for everyone. The type of incision previously made is one important determinant. For example, if you had a classical incision through the uterus, which is high up on the uterus, an attempted vaginal birth would not be a good idea because there is a risk of uterine rupture during labour. Multiple foetuses, medical complications such as high blood pressure or abnormal foetal position may all require a caesarean section and prevent a VBAC trial. If a VBAC is attempted you will need foetal monitoring and IV in case a section becomes necessary. The risk of uterine rupture is low, but if it occurs, the consequences can be severe for both the mother and the baby.
A machine that assists adults or children to breathe. This most often refers to newborn infants who sometimes have breathing problems so severe that they need help from a breathing machine. If your baby was born with lung problems or didn't breathe on his own he may be connected to a ventilator. Lung immaturity in prematurely born infants is the most common reason for a newborn to require a ventilator.
Also called vernix caseosa. A cheesy, white substance that covers a baby's skin at birth. The vernix is secreted by the sebaceous glands around the 20th week to protect the baby's skin from the amniotic fluid. Without the vernix, the baby would have very wrinkled skin from constant exposure to the watery amniotic fluid. The amount of vernix present decreases toward the end of gestation. Remaining vernix is washed off after birth. The loss of vernix may cause the skin to peel during the first postnatal week.
A vertex presentation is the most common and desirable. In this position the baby's head enters the birth canal first.
Very low birth weight (VLBW)
A birth weight of less than 1500 grams. Babies with such a low birth weight are almost always very prematurely born. About 1.3% of all births result in babies with a birth weight of less than 1500 grams.
Able to survive. Refers to the condition of a newborn.