The Hormones of Birth: How They Work and What Happens When Labor is Interrupted
While the predominant approach to birth in many countries suggests that extensive interventions and monitoring are necessary for safe delivery, the truth is that our bodies are naturally designed to carry out this process from start to finish without external assistance, except in rare cases where complications arise.
In fact, monitoring and interventions can often times hinder the beautiful and natural process and actually lead to problems, despite that not being the goal.
Labor and birth are guided by a delicate balance of hormones. These hormones not only facilitate the progression of labor but also play a critical role in bonding, recovery, and the overall well-being of both mother and baby. Understanding how these hormones work during a normal physiological birth—and the potential consequences of interrupting or manipulating the process—can empower women to make informed choices about their birth experiences. Let’s take a look at what they are, how they work, and how to avoid common things that disrupt this naturally occurring hormonal dance.
The Key Hormones in Birth
1. Oxytocin: The Love Hormone
Oxytocin is the primary hormone driving labor. It causes the uterus to contract and helps the cervix dilate, moving labor along naturally. Beyond its physical role, oxytocin fosters feelings of love and connection, which are crucial for bonding with your baby after birth.
How it works in labor: Oxytocin is released in waves, increasing in intensity as labor progresses. The natural surge of oxytocin during the pushing stage also triggers the ejection reflex, helping the baby to be born efficiently.
After birth: Oxytocin continues to play a role in expelling the placenta and reducing postpartum bleeding. It also supports breastfeeding by triggering the milk ejection reflex.
2. Endorphins: Nature’s Pain Relief
Endorphins are the body’s natural painkillers, released in response to the intensity of labor. These hormones help women cope with the physical sensations of childbirth and can create a sense of euphoria or empowerment.
How it works in labor: As contractions become stronger, endorphin levels rise to match the intensity. This helps women enter an almost meditative state, often referred to as "labor land."
After birth: High endorphin levels can contribute to the initial feelings of bliss and bonding with your baby.
3. Adrenaline: The Fight-or-Flight Hormone
Adrenaline, while often thought of as a stress hormone, also has a role in labor. It can provide a burst of energy during the final stages of labor, helping the mother push effectively. However, too much adrenaline at the wrong time can interfere with the process.
How it works in labor: A natural spike in adrenaline occurs as the baby is about to be born, increasing alertness and energy for the final stage.
Challenges: If adrenaline levels are too high early in labor, they can inhibit oxytocin production and stall labor.
4. Prolactin: The Mothering Hormone
Prolactin is the hormone of lactation and nurturing. It supports the mother’s instinct to care for and protect her newborn.
How it works in labor: Prolactin prepares the body for breastfeeding and promotes maternal behaviors.
After birth: It remains essential for milk production and strengthens the bond between mother and baby.
The Impact of Interventions on Hormonal Flow
Modern medical interventions can be life-saving when necessary, but they often disrupt the natural hormonal process of birth. Here’s how common interventions can affect this delicate balance:
1. Induction and Augmentation with Synthetic Oxytocin (Pitocin)
Effect on oxytocin: Synthetic oxytocin does not cross the blood-brain barrier, meaning it doesn’t trigger the same emotional and bonding effects as natural oxytocin.
Effect on endorphins: Contractions induced by Pitocin are often more intense and closer together, which can make it harder for the body to produce enough endorphins to cope with the pain, leading to increased use of pain relief.
Overall impact: The lack of natural oxytocin release can make labor feel more mechanical and less intuitive, potentially impacting bonding and breastfeeding.
2. Epidural Anesthesia
Effect on hormones: Epidurals can reduce the body’s production of oxytocin, leading to longer labors and an increased likelihood of additional interventions, such as forceps or vacuum delivery.
Effect on endorphins: By numbing the sensations of labor, epidurals disrupt the natural feedback loop that helps endorphin levels rise in response to contractions.
Overall impact: While epidurals provide effective pain relief, they can interfere with the hormonal cascade that supports bonding and the transition to postpartum.
3. Cesarean Birth
Effect on hormones: Scheduled or emergency Cesareans bypass the natural hormonal process of labor. Without the oxytocin surge that happens during vaginal birth, bonding and breastfeeding can initially be more challenging. While a C-section is sometimes the safest and best option, these cases are rare. Unfortunately, C-sections are often overused and can result from the cascade of interventions, such as inductions with synthetic oxytocin (Pitocin), epidurals, and restricted movement, among others.
Overall impact: Babies born by Cesarean may miss out on exposure to maternal microbiota, which can influence their gut health and immune system.
4. Continuous Fetal Monitoring and Restricted Movement
Effect on hormones: Being confined to a bed due to an epidural and subjected to continuous monitoring can increase stress and adrenaline levels, which may inhibit oxytocin and slow labor.
Several studies have found that continuous electronic fetal monitoring (EFM) during labor is associated with increased rates of cesarean sections. For example:
A scoping review reported that the largest study demonstrated an 81% increased risk of primary cesarean birth when EFM was used during labor.
A prospective randomized study of 483 high-risk obstetric patients found that the cesarean section rate was significantly higher in the monitored group (16.5%) compared to the auscultated group (6.8%).
These findings suggest that while EFM is intended to monitor fetal well-being, its use may contribute to higher cesarean rates.
Overall impact: Restricted movement can make it harder for the baby to navigate the birth canal and may lead to more interventions.
Why Protecting the Hormonal Flow Matters
For these reasons, it is so important to be aware of what constitutes as a normal physiological birth, and understand what is each intervention, why it is being done/used, and what their effects are.
The hormonal interplay during labor and birth is finely tuned to optimize outcomes for both mother and baby. Disruptions to this process can lead to:
Stalled or prolonged labor: High levels of adrenaline or reduced oxytocin can slow down contractions.
Increased pain perception: Without adequate endorphin production, the sensations of labor may feel more intense.
Challenges with bonding and breastfeeding: Oxytocin is crucial for establishing an emotional connection and initiating breastfeeding.
Postpartum recovery difficulties: Hormonal disruptions can contribute to postpartum hemorrhage, delayed milk production, or emotional challenges like postpartum depression.
Supporting the Hormonal Process
You have more control than you think! Be informed and ready to ask questions, state your preferences/birth plan, and be fully informed with all the information you need before consenting.
To protect the natural hormonal flow of labor, consider the following:
Choose a supportive birth environment: Dim lighting, privacy, and a calm atmosphere can help reduce stress and promote oxytocin release.
Limit unnecessary interventions: Work with your care provider to minimize interventions unless medically necessary.
Stay mobile: Upright positions and freedom to move can encourage the baby’s descent and support natural hormone production.
Use natural pain management: Techniques like water immersion, massage, and breathing exercises can enhance endorphin production.
Foster immediate skin-to-skin contact: After birth, uninterrupted skin-to-skin time helps promote oxytocin release and bonding.
Conclusion
Birth is a physiological process guided by a powerful hormonal interplay. While medical interventions have their place, it’s important to recognize how they can disrupt this natural balance. By understanding the role of hormones and making informed choices, you can better protect the hormonal flow of labor and set the stage for a positive birth and postpartum experience. Remember, your body was designed to give birth, and these incredible hormones are there to support you every step of the way.
