Doctors Now Understand Science Behind Labor

Scientists have a better grasp on how the human body sustains itself during labor—leading to a better understanding of how to cope with prolonged birth.

Doctors Now Understand Science Behind Labor

The human body is an amazing thing, especially when it comes to pregnancy and childbirth. But there is much that scientists still don't understood about how we operate—like how is it that a woman's contractions get stronger as labor progresses, despite the rest of her body getting weaker from lack of oxygen, blood loss and sheer exhaustion?

New research out of the University of Liverpool in the UK is helping to explain exactly how a woman's body can do this amazing feat: through something called hypoxia-induced force increase (HIFI), which occurs in the uterine muscles as a result of lack of blood supply and oxygen. It essentially means that the body kicks into high gear when resources are low. And it has a protective effect on the process of labor, allowing a woman to progress despite being low on blood and air.

Wonder Woman mode

This key finding, published in the journal Proceedings of the National Academy of Sciences, seems to indicate that a woman's body goes into Wonder Woman mode during labor, similar to when the heart experiences hypoxic preconditioning to protect it from oxygen loss. It's especially valuable knowledge when labor can carry on for seemingly endless hours and given that some women can become insensitive to oxytocin, the hormone that helps stimulate contractions.

"During labors, the womb contracts and relaxes intermittently and vigorously until the baby passes through the birth canal safely. However, with each womb contraction, the oxygen supplying it would decrease briefly and increase again during the womb being relaxed. This process of contraction/relaxation and intermittent decrease in oxygen would initiate a mechanism inside the womb itself to protect its power from weak contractions that are not enough to push the baby out," says study author Mohammed Alotaibi, Ph.D.

A reduction in prolonged labors

The hope is that this new research into an important uterine trigger can help move along difficult, prolonged labors, thereby reducing the need for emergency C-sections.

"These findings can help shorten the long birth process by promoting the strong contractions that are required to deliver the baby," Alotaibi says, while noting that if HIFI naturally occurs during labor, then a normal, timely delivery should be expected. But for those whose labors stall or slow down, certain mechanisms can induce HIFI—including an entryway on the womb cell membrane known as adenosine or ATP, an increase of prostaglandin, and activation of the protein phospholipase C, according to Alotaibi—all of which should be administered at the proper stage of labor.

"It is also important to be very careful when using the oxytocin hormone if labor is to be induced to avoid early HIFI activation while the labor is in its very early stages—i.e. when the cervix still not effaced and dilated—as this may result in a fetus being distressed and the need for emergency C-section," Alotaibi advises.

No laboring woman wants to face such interventions, but when you're entering the umpteenth hour of labor, it may be the best choice if that's what doctors are recommending. To avoid an unplanned C-section, ask your doctor ahead of time what you can do to encourage a vaginal delivery and consider hiring a doula. If you've had a previous C-section, talk to your doc about the possibility of a VBAC. What's most important is that you educate yourself on the most common interventions during labor and delivery so you know all the potential outcomes. Then, try to trust that your body is doing all that it can to get that baby out!