If your baby is in the more common frank breech position (bottom down with legs extended up toward the face), vaginal delivery is a possibility, depending on your baby's estimated weight and your doctor or midwife's experience.  In the case of a healthy mother with a full term healthy baby of normal size in a breech presentation, vaginal delivery at full term ought to be an option to be given serious consideration.  It is more likely to be considered if you have previously had a vaginal birth and do not have a history of large babies.

The knee presentation (incomplete) breech (one or both of your baby's knees or legs is the closest part to your vagina) and complete (the baby is sitting cross-legged) breech positions make vaginal delivery extremely difficult, and a caesarean will usually be advised. 

If you do decide to aim for a vaginal breech birth, you will probably be advised to get to hospital early in labour for continuous fetal monitoring, in case of cord prolapse.  You may also be advised to have an epidural, to help avoid pushing too early, and this can also be topped up if a caesarean becomes necessary.  You are also more likely to have an episiotomy and assisted delivery using forceps.

Why might vaginal birth be dangerous for a breech baby?

The reason that breech birth is a concern is that the head is usually the biggest part of the baby, so it's possible that the rest of the body could be born before the cervix is fully dilated. Once the umbilical cord contacts room conditions, it tends to congeal, and stops bringing oxygen to the baby. If this happens before the baby's head is born, the baby isn't getting oxygen through the cord and can't breathe because the mouth isn't out yet.

If you have a waterbirth, the baby's body will be born into conditions that simulate the uterus, and the cord is no more likely to congeal than if it were still inside.  However, there are still concerns that the cord could be pinched between the baby and the pelvis.

If it does appear that the baby's oxygen supply is compromised, for whatever reason, an airway can be established even before the head is born by holding the vaginal tissues away from the baby's face to establish an airway while waiting for the cervix to finish dilating and the baby's head to mould appropriately. 

Cord prolapse

Cord prolapse is more common in breech (3.7%) than vertex (0.3%) presentations because the baby*s bottom or legs do not fit the pelvis as closely as the head and there is more chance that the cord may slip through. However, for the same reasons the pressure on the cord may not be as great and therefore a cord prolapse with a breech may not be the immediately life-threatening event that often presents with a head down baby.

The Premature Breech

A caesarean will generally be advised if you go into labour before 37 weeks gestation.  Even though premature babies weigh less and have smaller bodies than full-term infants, their heads are quite large.  When combined with a small body, a large head can make problems during vaginal delivery more likely.   There may not be enough pressure on the cervix to fully dilate it, causing head entrapment.

Obstetric skills

The Royal College of Obstetrics and Gynaecology recognizes that many recently qualified obstetricians lack experience of vaginal breech birth.  This is due to the rising caesarean rate and the reorganization of junior doctors* work patterns.  There are now a reduced number of vaginal breech births managed by an increased number of trainees, who do fewer hours.  In one major hospital, there was a tenfold reduction in vaginal breech birth experience for UK registrars in 1997 compared to 1987.  Alternative methods of training, using videos, models and scenario training, are currently being developed. 

REFERENCES

http://www.gentlebirth.org/archives/breech.html

http://www.rcog.org.uk/guidelines/breech.html

http://pregnancy.about.com/health/pregnancy

http://obgyn.net

http://www.aims.org.uk

Kitzinger, S. (1989) The New Pregnancy and Childbirth. London: Penguin.

Bennett, V.R. and Brown, L.K. (Eds) (1993) Myles Textbook for Midwives. 12th ed.

Edinburgh: Churchill Livingstone.

Jane O'Hara

June 2000