Hormones & Birth: How Women’s Bodies are Built to Withstand Labor

How much will the contractions hurt? How can I possibly push an eight-pound baby out of my vagina? If you’re pregnant for the first time and nearing your due date, these are totally natural anxieties and questions about birth. Other friends and relatives who have gone through labor, though well-intentioned, can often amplify these fears of the unknown. Plus, how can we not mention Hollywood, which tends to emphasize the terrifying rather than the beautiful aspects of labor? (Cue Katherine Heigl's scream-filled scene in Knocked Up.)

 

Let’s be real: Yes, birth can be painful. After all, the uterus intensely contracts and the pelvis opens so the baby can make its way through the birth canal. Sensations like cramping, aching, burning, stretching, and pressure may occur.

 

But here’s the thing: Women’s bodies are evolutionarily designed to give birth. “I advise patients to remember that labor is a natural process that women have been going through since the beginning of time,” says Dr. Nathaniel DiNicola, an OB-GYN and faculty member at George Washington University in Washington, D.C. “A woman’s body instinctively knows what to do and how to give birth.” In other words, birth isn’t like that recurring nightmare when you walk into class, realize there’s an exam, and you haven’t studied at all. (Anyone else?)

 

In unmedicated labors, a woman’s body provides pain relief and support—without her needing to do a thing—in the form of hormones. Dr. Sarah Buckley is famous for her research and work on hormones during labor and birth. Her Hormonal Physiology of Childbearing report examines the benefits of the innate biological processes that promote healthy outcomes for mothers and babies. Below, we’ve broken down some of Dr. Buckley’s and others’ research on three key hormones released during intervention-free labors that naturally manage pain and facilitate birth.

 

Oxytocin

You may know oxytocin as “the love hormone.” In addition to kicking in when cuddling with your partner or after sex, oxytocin provides warm and fuzzy feelings after giving birth. However, many people don’t know that oxytocin also instigates uterine contractions during labor. These contractions may be painful, but they’re also what push the baby down and through the pelvis to be born in vaginal deliveries.

 

Keeping oxytocin levels high during birth can also protect mothers against postpartum hemorrhage. While some blood is completely normal during birth, postpartum hemorrhage refers to losing a dangerous amount of more than 500 milliliters. In addition to facilitating uterine contractions, oxytocin also responsible for clamping the uterus after birth. This helps to prevent excess bleeding and postpartum hemorrhage.

 

Adrenaline

You’re likely familiar with adrenaline—the phrase “rush of adrenaline” is often used when describing intense experiences. When adrenaline is secreted by the adrenal gland, our sympathetic nervous system and fight-or-flight response become activated. This signals that we may be in danger. Ever noticed your heart racing walking down a dark street? This is adrenaline preparing your body to fight, flee, or freeze. Sometimes this even happens during situations that aren’t technically life-threatening, like speaking in public.

Adrenaline can help during labor, but it can also get in the way—timing is everything. During early labor, it’s best to keep adrenaline levels low. This lets oxytocin take over and keeps blood flowing to the uterus (instead of the limbs), which enables contractions and encourages birth. Staying relaxed, perhaps by breathing deeply, dimming the lights, or soaking in the bath, can be useful. This sends a message to your body and baby that everything is OK and safe. Higher levels of adrenaline during this time can increase the duration of labor, since your body senses it may be in danger and it’s therefore not a secure time or place to give birth.

 

But having higher levels of adrenaline is important when it comes time to push. When a mother feels the urge to push, they may suddenly experience dry mouth, dilated pupils, and a burst of energy—this is all due to high adrenaline. During a vaginal delivery, this surge of adrenaline helps a mother muster the strength to push the baby out.

 

Beta-Endorphin

Beta-endorphin is a natural opiate that acts similarly to pain-relieving drugs like morphine. Secreted by the pituitary gland, beta-endorphin creates feelings of pleasure and euphoria during moments of intense stress or pain, like labor. In fact, beta-endorphin levels during labor can reportedly reach the same levels as those found in male endurance athletes during maximal exercise on a treadmill. Crazy, right? Just as runner’s often talk about a “runner’s high,” beta-endorphin has the potential to take a birthing person into an internal, meditative-like state that works to better manage pain. A “birther’s high,” if you will.

 

It’s important to note that most of the research in this article was conducted on women who chose to have unmedicated births. Some interventions like epidurals and certain medications can interfere with the body’s natural ability to secrete the aforementioned hormones. At BINTO, we firmly believe in supporting mothers and their individual birthing choices. The journey doesn’t matter, as long as it leads to a healthy mother and baby. To learn more about hormones and how you can rely on them to support you during birth, whether on their own or in combination with other pain management solutions, talk with your provider.

 

Though pain can be frightening and inevitable during birth, it can be reassuring to know that your body and Mother Nature know exactly how to help. Hormones like oxytocin, adrenaline, and beta-endorphin have got your back (yep, and your uterus, too).

___________________________________________________

Written by English Taylor. Women's health freelance writer and editor. English went to the University of Virginia undergrad and Northwestern for graduate school. She currently lives in the bay area but hails from Nashville (one of our favorite places!).

5/5 (1)

Please rate this

Let's talk! We promise not to spam. Who likes that?!

Sign me up for the BINTO newsletter, updates and exclusive offers.