O is for Oxytocin

Oxytocin is a hormone that plays a role in regulating: social interaction, sexual reproduction, maternal-child boding, labor, and milk production. It is produced by the hypothalamus and released by into the blood by the posterior pituitary gland. Oxytocin is frequently referred to as the “love hormone” because its levels increase with physical affection.

Oxytocin in the Perinatal Period

Without a doubt, oxytocin is the do-it-all hormone when it comes to the perinatal period, starting from before conception! It:

  • is released during orgasm and is responsible for the relaxation (and sleepiness) that may be felt after sex.
  • is released when your nipples are stimulated (either to bring on or intensify contractions or during breastfeeding, as well as in response to the stretching of the cervix and uterus during labor.
  • works by positive feedback.
  • can be used (in synthetic form) to induce or augment labor (it’s the drug pitocin).
  • helps the uterus return to its pre-pregnancy size and tone.
  • is key in mother-child bonding for both the mother and the baby.
  • promotes movement of milk into the breast during nursing.
  • speeds up delivery of the placenta and reduces the risk of heavy bleeding by contracting the uterus.
    • It may be injected into the umbilical cord (that is still attached to the placenta) after delivery, or given through the IV line or as an intramuscular injection to the mother to control and reduce the risk of heavy bleeding.
    • Some OBs and midwives will let you nurse your baby immediately after delivery to get a non-synthetic oxytocin boost.

How does oxytocin work?

oxytocin feedbackOxytocin functions via a positive feedback mechanism, which means the effects of its release stimulates the body to release more of it. When you’re in labor your uterus contracts causing your cervix to stretch. These actions stimulate your body to release oxytocin. The oxytocin causes the contractions to continue, which means your body releases more of it. The buildup of oxytocin in the blood causes an increase in the frequency and intensity of your contractions. This process is self-limiting and it stops when your baby (and the placenta) have been delivered.

The feedback mechanism works the same way for oxytocin release during breastfeeding, with your letdown stimulating more oxytocin to be produced and released. When your baby stops feeding, the loop stops. During nursing, oxytocin can also act on the uterus, which is why you may experience uterine cramping or contracting while breastfeeding.



The information contained in this article is meant for educational purposes only and is not intended to diagnose, treat, prevent, or cure any disease. It does not take the place of consultation with your healthcare professional.

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