10 Powerful Effects of Oxytocin in Pregnancy, Birth and the Postnatal Period

Written By Amisha Abeyawardene

Oxytocin is often lovingly referred to as the “love hormone” — but in pregnancy, birth, and the postnatal period, it is far more than that. Oxytocin is a master hormone of physiology, orchestrating labour, protecting emotional wellbeing, supporting breastfeeding, and strengthening bonding between parent and baby.

As a doula, I see every day how understanding and protecting oxytocin can transform a birth experience. In this post, we’ll explore 10 evidence‑based effects of oxytocin in the body and why creating the right environment for this hormone matters so deeply.

1. Oxytocin Powers Uterine Contractions in Labour

Oxytocin is the hormone responsible for the rhythmic contractions of the uterus during labour. These surges work to thin and open the cervix and guide the baby down and out.

During spontaneous labour, oxytocin is released in pulses, creating a wave‑like contraction pattern that allows rest and recovery between surges. This pattern is most effective when labouring people feel safe, private, and supported.

2. Oxytocin Triggers Natural Pain Relief

Oxytocin released within the brain and spinal cord during labour stimulates the release of endogenous opioids — the body’s natural pain‑relieving chemicals.

These endorphins can:

  • Reduce the perception of pain

  • Create altered states of consciousness

  • Support focus and inward attention during labour

This is one reason why uninterrupted, low‑stress labour environments can significantly change how labour sensations are experienced.

3. Oxytocin Inhibits the Fight‑or‑Flight Response

Oxytocin actively suppresses the stress hormones adrenaline and cortisol. This inhibition of the fight‑or‑flight response is crucial during birth.

When oxytocin is flowing:

  • Muscles soften rather than tense

  • Blood flow is directed to the uterus

  • Labour progresses more efficiently

Conversely, fear, observation, bright lights, or feeling unsafe can interrupt oxytocin release and slow labour.

4. Oxytocin Creates a Hormonal Feedback Loop in Labour

Oxytocin works through a powerful positive feedback loop. As contractions bring the baby’s head down, pressure on the cervix stimulates even more oxytocin release — which strengthens contractions further.

This loop continues until birth and is most effective when labour is undisturbed. Supportive presence, reassurance, and protection of privacy help maintain this hormonal rhythm.

5. Oxytocin Promotes Vasodilation for Skin‑to‑Skin Warmth

Immediately after birth, oxytocin causes vasodilation (widening of blood vessels) in the chest and breasts.

This:

  • Warms the parent’s chest

  • Helps regulate the baby’s temperature

  • Supports early skin‑to‑skin contact

Skin‑to‑skin is not just emotional — it is a hormonally driven survival strategy.

6. Oxytocin Contracts the Uterus to Birth the Placenta

After the baby is born, oxytocin continues to work by contracting the uterus to birth the placenta. These contractions are essential for:

  • Preventing excessive bleeding

  • Supporting safe separation of the placenta

This stage of birth is still hormonally sensitive and benefits from calm, uninterrupted time.

7. Oxytocin Supports Uterine Healing Post‑Birth

In the days and weeks following birth, oxytocin continues to help the uterus contract and return to its pre‑pregnancy size — a process known as uterine involution.

Breastfeeding and close contact with baby stimulate ongoing oxytocin release, supporting both healing and bonding.

8. Oxytocin May Create an Amnesic Effect Around Labour

Oxytocin is thought to influence memory processing in the brain. Many people report that, over time, the intensity of labour sensations fades.

This protective amnesia may:

  • Support emotional integration of the birth experience

  • Reduce fear of future births

  • Strengthen positive memories associated with meeting the baby

9. Oxytocin Drives the Milk Ejection Reflex

Oxytocin is essential for breastfeeding. When a baby suckles, oxytocin causes the myoepithelial cells surrounding the milk‑producing glands (lactocytes) to contract.

This creates the milk‑ejection reflex — often called let‑down — allowing milk to flow to the baby.

Stress and anxiety can inhibit oxytocin, which is why emotional support is so important for early feeding.

10. Oxytocin Strengthens Bonding and Attachment

Oxytocin plays a central role in bonding between parent and baby. It heightens sensitivity to smell, touch, and eye contact, reinforcing caregiving instincts.

This hormone supports:

  • Emotional connection

  • Protective behaviours

  • Long‑term attachment patterns

Bonding is not a single moment — it is a hormonally supported process that unfolds over time.

Why Oxytocin Matters — and How a Doula Helps

Oxytocin thrives in environments that feel:

  • Safe

  • Calm

  • Private

  • Supported

As a doula, my role is to protect the conditions that allow oxytocin to flow — through emotional reassurance, physical support, advocacy, and continuity of care.

If you’re preparing for birth and want support that honours your physiology, hormones, and emotional wellbeing, I’d love to connect with you.

👉 Get in touch to learn more about how doula support can help you feel informed, confident, and deeply supported throughout pregnancy, birth, and the postnatal period.

Amisha Abeyawardene
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