Pelvic presentation: different forms
There are different types of breech presentation. In all of them, the baby’s head is at the top and the pelvis at the bottom of the womb. However, the position of the legs varies:
- Pure breech presentation: The baby has its legs folded up so that its feet are in front of its face. The breech therefore comes forward at birth.
- Perfect breech-foot position: Both legs are bent, i.e. the knees are drawn up towards the stomach.
- Imperfect breech-foot position: One leg is bent, the other is folded up as in the breech position.
- Perfect foot position: Both legs are extended downwards; the feet therefore move forward during birth.
- Imperfect foot position: One leg is extended downwards, the other is folded upwards.
- Perfect knee position: The baby is “kneeling”, i.e. both legs are bent backwards.
- Imperfect kneeling position: The baby only “kneels” with one leg, while the second is folded up.
The pure breech position is the most common form of breech presentation. Foot and breech-foot positions follow in second and third place. The knee position is very rare.
All variants of breech presentation are considered high-risk births that require special monitoring. Under certain circumstances, babies may have to be delivered by caesarean section.
Causes of breech presentation
For example, breech presentation can occur in a premature birth if the foetus has not yet turned at the time of the premature birth.
In the case of multiple pregnancies, in around a third of cases the two twins are twisted in relation to each other, i.e. one twin is in the cephalic position, with its head down, and the other twin is in the breech position, with its bottom down.
Even if the child is very large and therefore cannot turn so well, this often results in the breech position. The same applies if the child generally moves very little or too much or does not have enough room to turn due to an abnormality of the uterus or a narrowed pelvis.
An unfavorably positioned placenta and an umbilical cord that is too short are further possible reasons: They can prevent the baby from turning from the breech position to the cephalic position in time.
Pelvic presentation carries risks
External turning for breech presentation
Three to four weeks before the expected date of delivery, the doctor may attempt to turn the baby externally if it is in a breech position. The doctor attempts to turn the baby from the outside with gentle, pushing movements in the uterus so that it somersaults, so to speak, and the head comes to lie at the bottom. During this process, the baby is monitored with a contraction monitor (CTG).
The success rate of external turning is 50 to 70 percent. In the event that the attempt fails, everything should be prepared for an emergency caesarean section.
Prerequisites for a vaginal birth from breech presentation
If the baby meets a few requirements, a vaginal birth will be attempted in the clinic despite the breech presentation. The baby should not weigh more than 3500 grams. In addition, the baby’s abdominal circumference should not be significantly smaller than the circumference of the head so that the birth canal is already stretched when the abdomen emerges so that the head does not take too long to be born afterwards. The head should then emerge within 20 to 60 seconds. The expectant mother should be given a peridural anesthetic (epidural) to improve relaxation and speed up the birth.
