Breech birth is a birth in which the fetus's bottom is facing toward the cervix and the Censored pagel opening, rather than its head. Head-down is the usual position for a human baby. The bottom-down position, called breech presentation, presents some hazards to the baby during the process of birth, and the mode of delivery (vaginal versus Caesarean) is controversial in the fields of obstetrics and midwifery.
There are four categories of breech presentation:
Frank breech The baby's bottom comes first, and his or her legs are flexed at the hip and extended at the knees (with feet near the ears). 65-70% of breech babies are in the frank breech position.
Complete breech The baby's hips and knees are flexed so that the baby is sitting crosslegged, with feet beside the bottom.
Footling breech One or both feet come first, with the bottom at a higher position. This is rare.
Kneeling breech The baby is in a kneeling position, with one or both legs extended at the hips and flexed at the knees. This is rare.
About three to four percent of babies are in a breech presentation at the onset of labour. When labour is premature, the incidence of breech presentation is higher. At 28 weeks' gestation 25% of babies are breech, and the percentage decreases approaching term (40 weeks' gestation). This is because the weight of the baby's head encourages a head down position, and because as the baby grows and takes up more room in the uterus, she or he is less able to move about freely.
Certain factors can encourage a breech presentation. These include multiple pregnancy (twins, triplets or more), excessive amounts of amniotic fluid, hydrocephaly , anencephaly, very short umbilical cord, and uterine abnormalities. Babies with congenital abnormalities are more likely to be breech.
Though labour and vaginal birth are possible for the breech baby, certain fetal and maternal factors influence the safety of vaginal breech birth (see below). A majority of breech babies in the United States are delivered by Caesarean section.
Process of Breech Birth
As in labour with the baby in a normal head-down position, uterine contractions typically occur at regular intervals and gradually cause the cervix to become thinner and to open. In the commoner breech presentations, the baby’s bottom (rather than feet or knees) is what is first to descend through the maternal pelvis and emerge from the vagina. At the beginning of labor, the baby is generally in an oblique position, facing either the right or left side of the mother’s back. Because the baby’s bottom is a less efficient dilator than the head, the buttocks may remain high until late in labor. In order for the baby to pass through the mother’s pelvis, there is flexion at the side of the waist, so that one hip becomes the leading part. The mother’s pelvic floor muscles cause the baby to turn slightly so that the hips are born, usually one at a time, with the baby facing one of the mother’s inner thighs. At this time the baby’s shoulders are entering the mother’s pelvis, and the baby’s position adjusts again so that he/she is obliquely facing the mother’s back. The shoulders emerge as the baby’s head is entering the pelvis. The combination of maternal muscle tone and uterine contractions cause the baby’s head to flex, chin to chest. The baby’s position changes again so that she/he is facing the mother’s sacrum. Then the face emerges, and finally the back of the baby’s head. Because of pressure during labor and birth, it is normal for the baby's leading hip to be bruised and genitalia to be swollen; this resolves after birth. Babies who assumed the frank breech position in utero (legs extended) may continue to hold their legs in this position for some days after birth.
Risks of Breech Birth
Umbilical cord prolapse In the complete, footling, or kneeling breech, the lowermost parts of the baby do not completely fill the space of the dilating cervix. When the water breaks, it is possible for the umbilical cord to drop down and become compressed. This complication severely diminishes oxygen flow to the baby and the baby must be delivered immediately (usually by Caesarean section) so that he or she can breathe. If there is a delay in delivery, the brain can be damaged. Among full-term, head down babies, cord prolapse is quite rare, occurring in 0.4 percent. Among frank breech babies the incidence is 0.5 percent, among complete breeches 4-6 percent, and among footling breeches 15-18 percent.
Head entrapment In labor, the breech does not dilate the cervix as well as the head does in head-down babies. It is possible for the baby’s body to emerge while the cervix has not dilated enough for the head to emerge. Because the umbilical cord—the baby’s oxygen supply—is significantly compressed while the head is in the pelvis, it is important for delivery to be accomplished in a timely manner once the head is in the pelvis. If one of the baby’s arms is next to the head, the attendant may have to draw down the arm so that there is enough room for the head to be born. In order to have the smallest diameter (10 cm) moving through the pelvis, the baby’s head must be flexed (chin to chest). If the head is in a deflexed position, the head may become entrapped. Uterine contractions and maternal muscle tone encourage the head to flex. If the birth attendant pulls on the baby’s body, this action may deflex the head.
Arm entrapment This can entrap the head by not allowing enough room for it to be born.
Oxygen deprivation This may occur from cord prolapse or prolonged compression of the cord during birth, as in head entrapment. If oxygen deprivation is prolonged, it may cause permanent neurological damage or death.
Injury to the brain and skull In breech birth the head passes through the maternal pelvis rapidly, causing compression and decompression to occur within a few minutes. In contrast, a baby going through labor in the head-down position usually experiences gradual molding (temporary reshaping of the skull) over the course of a few hours. This sudden compression and decompression in breech birth may cause no problems at all, but it can injure the brain. This injury is more likely in preterm babies.
Damage resulting from rough handling during delivery A majority of full-term term frank breech babies would be born without problems even without assistance. However, in a large minority of cases, expert assistance is needed for the baby to be born safely. (It is important to note that some breech babies suffer complications or die despite expert assistance—not all injuries are preventable.) If the doctor, midwife, or unskilled attendant intervenes when action is not necessary or does not use proper maneuvers to resolve complications, permanent damage may occur. For instance, pulling on the baby can cause deflexion of the head or entrapment of one or both arms, which can delay completion of delivery long enough to cause damage or death from oxygen deprivation. Squeezing the baby’s abdomen can damage internal organs. Positioning the baby incorrectly while using forceps to deliver the aftercoming head can damage the spine or spinal cord. It is important for the birth attendant to be knowledgeable, skilled, and experienced with breech birth. In the United States, because Cesarean section is increasingly being used for breech babies, fewer and fewer birth attendants are developing these skills.
Factors Influencing the Safety of Breech Birth
Type of breech presentation The frank breech has the most favorable outcomes in vaginal birth, with many studies suggesting no difference in outcome compared to head down babies. (Some studies, however, find that planned caesarean sections for all breech babies improve outcome. The difference may rest in part on the skill of the doctors who delivered babies in different studies.) Complete breech presentation is the next most favorable position, but these babies sometimes shift and become footling breeches during labour. Footling and kneeling breeches have a higher risk of cord prolapse and head entrapment.
Parity Parity refers to the number of times a woman has given birth before. If a woman has given birth vaginally, her pelvis has "proven" it is big enough to allow a baby of that baby's size to pass through it. However, a head-down baby's head often molds (shifts its shape to fit the maternal pelvis) and so may present a smaller diameter than the same size baby born breech. Research on the issue has been contradictory as far as whether vaginal breech birth is safer when the mother has given birth before, or not.
Fetal size in relation to maternal pelvic size If the mother's pelvis is roomy and the baby is not large, this is favorable for vaginal breech delivery. However, prenatal estimates of the size of the baby and the size of the pelvis are fairly unreliable.
Hyperextension of the fetal head This can be evaluated with ultrasound. Less than 5% of breech babies have their heads in the "star gazing" position, face looking straight upwards and the back of the head resting against the back of the neck. Caesarean delivery is absolutely necessary, because vaginal birth with the baby's head in this position confers a high risk of spinal cord trauma and death.
Maturity of the Baby Premature babies appear to be at higher risk of complications if delivered vaginally than if delivered by caesarean section.
Progress of Labour A spontaneous, normally progressing, straightforward labour requiring no intervention is a favourable sign.
Second Twins If a first twin is born head down and the second twin is breech, the chances are good that the second twin can have a safe breech birth.
Birth Attendant's Skill and Experience with Breech Birth The doctor's or midwife's level of skill and number of breech babies' births assisted is of crucial importance. Many of the dangers in vaginal birth for breech babies come from mistakes made by birth attendants.
Diagnosis of Breech Presentation
Early in pregnancy the baby changes position freely and frequently. By 28 weeks’ gestation, most babies are head-down most of the time. The mother carrying a breech fetus often feels that there is a hard, round part of the baby under her ribs; she feels kicking in the lower part of her uterus or around her umbilicus rather than at the top of her uterus; she may feel the baby hiccupping just under her ribs; and she often states something is different than in previous pregnancies, if she has previously given birth to head-down babies. The midwife or doctor can usually feel the baby’s position by palpating the mother’s abdomen (Leopold’s maneuvers ). The baby’s head and bottom may feel similar, but if the head is in the top of the uterus, it can be wiggled without moving the baby’s whole body. Listening to the baby’s heartbeat with a stethoscope or fetoscope can also indicate whether the baby is breech. Hearing the heartbeat above the mother’s umbilicus suggests a breech presentation. Listening to the fetal heartbeat with an ultrasound-based electronic device does not give the same information because it can pick up the fetal heartbeat from many different locations. If the baby is breech, the mother’s uterus may measure larger than expected for how far along the pregnancy has progressed. If it is late in pregnancy and the cervix has opened slightly, the midwife or doctor may be able to confirm head-down presentation by feeling the sagittal suture than runs between the baby’s unfused skull bones. An ultrasound scan can visualize the fetus and reveal the position.
Turning the Baby to Avoid Breech Birth
Many methods have been used successfully to turn breech babies. These include:
External cephalic version (a midwife or doctor turns the baby by manipulating her/him through the mother's abdomen, while listening to the heartbeat to be sure the umbilical cord is not compressed)
Acupuncture and moxibustion
Maternal positioning, for a few minutes several times a day, to give the baby more room and encourage turning (including the knee-chest position, the all-fours position, crawling, and lying down with several pillows under the mother's buttocks to elevate her pelvis)
Homeopathy (Pulsatilla 30 X is usually recommended, or, if the mother feels particularly fearful or felt frequently anxious earlier in pregnancy, Ignatia 30 C)
Swimming
Enticing the baby to turn (the mother asks the baby to turn, plays music softly at the lowest part of her uterus, or shines a flashlight on the lower part of her uterus; she may also put a package of frozen peas wrapped in a towel at the spot on her abdomen where the baby's head is for 3-5 minutes)
Visualization (the mother imagines, with pictures in her mind, the baby turning head down and remaining that way through labour)
Breech Birth versus Caesarean Section
Cesarean section is the most common way to deliver a breech baby in the U.S. and Great Britain. Like any major surgery, it involves risks. Maternal mortality is significantly increased by Caesarean section. There is risk of injury to the mother's internal organs, injury to the baby, and severe hemorrhage requiring hysterectomy with resultant infertility. The same birth injuries that can occur in vaginal breech birth can also occur in ceasarean breech delivery because of difficulty extracting the baby. If a caesarean is scheduled in advance (rather than waiting for the onset of labor) there is a risk of accidentally delivering the baby too early, so that the baby might have complications of prematurity. The mother's subsequent pregnancies will be riskier than they would be after a vaginal birth (risk of unexplained stillbirth, uterine rupture, placental abnormalities). If the incision into the uterus has to be enlarged or made into a "T" shape, the risk of uterine rupture in future pregnancies will be significant, with its risk of damage or death to both mother and future baby.
Normal vaginal birth should only be attempted if ultrasound shows that the baby is in a favorable breech position. Most babies will do very well during a breech delivery, but it is always possible that the baby will be injured.
In many less wealthy countries the availability of caesarean surgery is limited, the cost to the family can be catastrophic, and future risks may be significantly higher. For instance, if a woman with a caesarean scar lives two days' journey from a hospital where a caesarean can be performed, her risk from that scar will be much higher than the risk in a woman in a richer country.
External Links
http://www.birthdiaries.com/diary/47vbirth.htm
Photographs showing the safe birth of a breech baby.
http://news.bbc.co.uk/1/hi/health/2031173.stm
Breech birth controversies in Great Britain.
References
Banks, Maggie. Breech Birth Woman Wise. Birthspirit Books, 1998.
Fraser, Diane and Cooper, Margaret (Eds). Myles Textbook for Midwives, 14th edition. Churchill Livingstone, 2003.
Frye, Anne. Holistic Midwifery: A Comprehensive Textbook for Midwives in Homebirth Practice, Vol I, Care During Pregnancy. Labrys Press, 1995.
Gabbe, Steven; Niebyl, Jennifer; and Simpson, Joe Leigh (Eds). Obstetrics: Normal and Problem Pregnancies, 4th edition. Churchill Livingstone, 2002.
Oxorn, Harry. Human Labor and Birth, 5th edition. Appleton & Lange, 1986.
Waites, Benna. Breech Birth. Free Association Books, 2003.
Last updated: 05-03-2005 02:30:17
