The Power of Hormones in Labour: How Hormones Work Together to Support Childbirth

Hormones involved in pregnancy, birth and postpartum

Hormones play a powerful and coordinated role in the process of labour, each contributing to a complex, carefully orchestrated process. From initiating contractions (or surges) to creating bonds between mother and baby, these hormones—oxytocin, oestrogen, progesterone, beta-endorphins, adrenaline, cortisol, and prolactin—are essential to a successful and positive birth experience. Here, we explore each hormone’s unique role in labour, its functions, and how they work in harmony to bring new life into the world.

1. Oxytocin: The Love Hormone

Known as the "love hormone," oxytocin plays a central role in initiating labour. It is responsible for causing the uterus to contract, which begins the process of dilation. Oxytocin levels rise significantly as labour progresses, promoting stronger, more regular contractions. This hormone not only drives the physical aspects of childbirth but also enhances feelings of calm and closeness, reinforcing the mother’s bond with her baby.

As labour intensifies, oxytocin continues to stimulate the uterus, helping it contract effectively and rhythmically. In physiological birth settings, the gentle, supportive environment further boosts oxytocin levels, while stress and interruptions may lower it. Practicing relaxation techniques, creating a comfortable environment, and receiving continuous support all help maintain high oxytocin levels, facilitating smoother labour progress.

2. Oestrogen: Priming the Body for Labour

Oestrogen is essential in preparing the body for labour. During pregnancy, oestrogen levels increase gradually, stimulating the growth of the uterus and enhancing blood flow to both the mother and baby. This hormone also readies the body by increasing oxytocin receptors in the uterus, making it more sensitive to the effects of oxytocin when labour begins.

As labour approaches, a sharp increase in oestrogen levels helps prime the uterus for contractions. It also softens the cervix, making it more pliable and ready for dilation. This hormone is one of the key factors in kickstarting labour naturally, ensuring the mother’s body is fully prepared for the stages of childbirth.

3. Progesterone: The Pregnancy Sustainer

Progesterone is known as the pregnancy-maintaining hormone - this is why you will often find that pregnant people who have suffered from pregnancy loss/miscarriage are prescribed progesterone suppositories. Throughout pregnancy, progesterone keeps the uterus relaxed, preventing contractions until the baby is ready for birth. It also supports the formation of the placenta, nourishing the baby and allowing it to grow.

As labour draws near, progesterone levels drop significantly, allowing oestrogen and oxytocin to take the lead. This reduction in progesterone’s calming effects is crucial for the onset of labour; by stepping aside, progesterone allows oxytocin to initiate contractions and prepare for birth. In essence, the drop in progesterone creates the conditions for the body to transition from pregnancy to the first room of labour.

4. Beta-Endorphins: Nature’s Pain Relief

When labour becomes intense, the body produces beta-endorphins, natural pain-relieving hormones that help mothers manage pain and discomfort. Often called “nature’s painkillers,” beta-endorphins create a feeling of euphoria and help the mother stay focused. These endorphins counterbalance the pain and exertion of labour, offering a coping mechanism that keeps stress levels manageable.

Interestingly, beta-endorphins not only help with pain but also enhance bonding. After birth, elevated endorphin levels create feelings of bliss and love, strengthening the mother-baby connection. While they work in synergy with oxytocin, these hormones also reduce stress, ensuring that labour remains as manageable and rewarding as possible.

5. Adrenaline: The Energy Booster

Adrenaline is usually associated with the “fight or flight” response, but in labour, it serves as an energy booster. Toward the final stages of labour, as the body prepares to push, adrenaline provides the burst of energy necessary to deliver the baby. This hormone’s effects can be particularly beneficial during the pushing phase, enabling the mother to focus and summon the strength needed for the final stages of delivery.

However, excessive adrenaline too early in labour can slow progress by inhibiting oxytocin production. This is why it’s essential for labouring mothers to feel safe and supported; a calm environment keeps adrenaline levels low until they’re needed most. The right balance of adrenaline provides a powerful energy surge exactly when it’s required, aiding in a smoother birth.

6. Cortisol: Adaptation and Resilience

Like adrenaline, cortisol is typically a stress hormone. During labour, cortisol is present in a controlled manner, helping both mother and baby adapt to the stress of childbirth. Cortisol supports blood flow and oxygen delivery, essential for keeping energy levels stable as labour progresses. Elevated cortisol levels in the baby help prepare it for life outside the womb by supporting lung development and other key functions.

While cortisol provides necessary resilience during labour, managing stress and maintaining a calm birthing environment prevents excessive cortisol, which could hinder oxytocin and slow labour progression. Cortisol’s regulated presence allows the body to adapt to the intensity of childbirth while protecting the wellbeing of both mother and baby.

7. Prolactin: The Bonding and Breastfeeding Hormone

Prolactin is often called the “mothering hormone” due to its role in bonding and breastfeeding. After the baby is born, prolactin levels rise to support lactation, allowing the mother to feed her newborn. This hormone also fosters feelings of protectiveness, helping the mother respond to her baby’s needs with a strong sense of nurturing and care.

Prolactin plays a crucial role in the early moments of bonding, promoting emotional closeness between mother and baby. Its effects extend beyond birth, supporting breastfeeding and the mother’s role in caring for her newborn. For a smooth start to breastfeeding, prolactin works in tandem with oxytocin, creating a strong foundation for maternal care and baby’s development.

Hormonal Harmony in Labour

Each of these hormones—oxytocin, oestrogen, progesterone, beta-endorphins, adrenaline, cortisol, and prolactin—contributes to a natural and successful birth experience. By working together, they guide the body through the complex stages of labour, supporting the physical demands of childbirth while also fostering emotional bonding and nurturing instincts.

Understanding the power of hormones in labour reveals the body’s remarkable ability to navigate the birth process. With the right support and environment, this hormonal symphony unfolds seamlessly, leading to a positive, empowering birth for mother and baby alike.

Our antenatal courses in Tunbridge Wells and East Grinstead provide detail on how we can create the perfect environments to help foster the ideal balance in hormones.