The dance of breech and the case for unmedicated birth

10/10/2020

Dr. David Hayes explains the intricate dance of giving birth and why epidural anesthesia can interfere with that process:

There are good reasons to avoid any anesthesia in birth and even more reasons to avoid epidural anesthesia. Physiologic birth, whether breech or cephalic, isn't just mom pushing a baby out. It's a finely choreographed dance, a cooperative interplay between mom and baby. Both have a role to play. As babies descend through the pelvis, they encounter boney protuberances, muscles, ligaments, the curvature of the sacrum, and the changing dimensions of the pelvic walls. Babies are flexible and can rotate and flex to navigate the passage, and the pelvis itself is flexible and can move to accommodate the baby. But none of this is automatic. 

Healthy babies can move when they encounter objects in their path, but neurologically impaired "floppy" babies can not. Babies will instinctively try to keep their heads flexed, along with their bodies, which presents the smallest diameter to the pelvic passage. They will try to free their arms and legs from obstacles they encounter--not magic. Just a normal response to getting something stuck, but the effects are magic. 

A birth attended by a workshop participant
A birth attended by a workshop participant

The baby helps itself be born. The same is true for mom. When an obstacle is encountered passing through the pelvis, it hurts--a lot! The pelvis has some static flexibility, but that flexibility is greatly enhanced by the active movement of the mom. Squatting, lunging, stretching, whatever relieves the pain also relieves the obstruction. 

With any anesthesia the pain that provides that feedback to the mom is diminished and may not trigger movement. It may feel as though it's coming from some where other than its source and may trigger movement that is less helpful. With epidurals, not only is the feedback lost, but so also is the ability to move. Epidurals completely disconnect the mom from the process, and she is no longer able to make that contribution to the dance. The baby has to shoulder the burden of making its way out without that extra help from mom, and it has to navigate a pelvis that is not using its full flexibility in the process. 

This is not just an intuitively compelling story. Macharey 2017 looked at every breech birth in Finland between 2005 and 2014 to determine what risk factors were associated with poor perinatal outcomes and found epidural anesthesia to be one of those risk factors. 

Epidurals have their place in birth. They can give an exhausted mom the break that allows her to keep going. But it is undeniable that they increase the C section rate in all vaginal births and specifically worsen perinatal outcomes in vaginal breech births.