In the last weeks of pregnancy, a baby usually moves so his or her head is positioned to come out of the vagina first during birth. This is called a vertex presentation. A breech presentation occurs when the baby’s buttocks, feet, or both are positioned to come out first during birth. This happens in 3–4% of full-term births.
What are the different types of breech birth presentations?
- Complete breech: Here, the buttocks are pointing downward with the legs folded at the knees and feet near the buttocks.
- Frank breech: In this position, the baby’s buttocks are aimed at the birth canal with its legs sticking straight up in front of his or her body and the feet near the head.
- Footling breech: In this position, one or both of the baby’s feet point downward and will deliver before the rest of the body.
What causes a breech presentation?
The causes of breech presentations are not fully understood. However, the data show that breech birth is more common when:
- You have been pregnant before
- In pregnancies of multiples
- When there is a history of premature delivery
- When the uterus has too much or too little amniotic fluid
- When there is an abnormally shaped uterus or a uterus with abnormal growths, such as fibroids
- The placenta covers all or part of the opening of the uterus placenta previa
How is a breech presentation diagnosed?
A few weeks prior to the due date, the health care provider will place her hands on the mother’s lower abdomen to locate the baby’s head, back, and buttocks. If it appears that the baby might be in a breech position, they can use ultrasound or pelvic exam to confirm the position. Special x-rays can also be used to determine the baby’s position and the size of the pelvis to determine if a vaginal delivery of a breech baby can be safely attempted.
Can a breech presentation mean something is wrong?
Even though most breech babies are born healthy, there is a slightly elevated risk for certain problems. Birth defects are slightly more common in breech babies and the defect might be the reason that the baby failed to move into the right position prior to delivery.
Can a breech presentation be changed?
It is preferable to try to turn a breech baby between the 32nd and 37th weeks of pregnancy. The methods of turning a baby will vary and the success rate for each method can also vary. It is best to discuss the options with the health care provider to see which method she recommends.
Medical Techniques
External Cephalic Version (EVC) is a non-surgical technique to move the baby in the uterus. In this procedure, a medication is given to help relax the uterus. There might also be the use of an ultrasound to determine the position of the baby, the location of the placenta and the amount of amniotic fluid in the uterus.
Gentle pushing on the lower abdomen can turn the baby into the head-down position. Throughout the external version the baby’s heartbeat will be closely monitored so that if a problem develops, the health care provider will immediately stop the procedure. ECV usually is done near a delivery room so if a problem occurs, a cesarean delivery can be performed quickly. The external version has a high success rate and can be considered if you have had a previous cesarean delivery.
ECV will not be tried if:
- You are carrying more than one fetus
- There are concerns about the health of the fetus
- You have certain abnormalities of the reproductive system
- The placenta is in the wrong place
- The placenta has come away from the wall of the uterus (placental abruption)
Complications of EVC include:
- Prelabor rupture of membranes
- Changes in the fetus’s heart rate
- Placental abruption
- Preterm labor
Vaginal delivery versus cesarean for breech birth?
Most health care providers do not believe in attempting a vaginal delivery for a breech position. However, some will delay making a final decision until the woman is in labor.
The following conditions are considered necessary in order to attempt a vaginal birth:
- The baby is full-term and in the frank breech presentation
- The baby does not show signs of distress while its heart rate is closely monitored.
- The process of labor is smooth and steady with the cervix widening as the baby descends.
- The health care provider estimates that the baby is not too big or the mother’s pelvis too narrow for the baby to pass safely through the birth canal.
- Anesthesia is available and a cesarean delivery possible on short notice
What are the risks and complications of a vaginal delivery?
In a breech birth, the baby’s head is the last part of its body to emerge making it more difficult to ease it through the birth canal. Sometimes forceps are used to guide the baby’s head out of the birth canal. Another potential problem is cord prolapse.
In this situation the umbilical cord is squeezed as the baby moves toward the birth canal, thus slowing the baby’s supply of oxygen and blood. In a vaginal breech delivery, electronic fetal monitoring will be used to monitor the baby’s heartbeat throughout the course of labor. Cesarean delivery may be an option if signs develop that the baby may be in distress.
When is a cesarean delivery used with a breech presentation?
Most health care providers recommend a cesarean delivery for all babies in a breech position, especially babies that are premature. Since premature babies are small and more fragile, and because the head of a premature baby is relatively larger in proportion to its body, the baby is unlikely to stretch the cervix as much as a full-term baby. This means that there might be less room for the head to emerge.
Want to Know More?
Compiled using information from the following sources:
- ACOG: If Your Baby is Breech
- William’s Obstetrics Twenty-Second Ed. Cunningham, F. Gary, et al, Ch. 24.
- Danforth’s Obstetrics and Gynecology Ninth Ed. Scott, James R., et al, Ch. 21.
