Hormones and Their Role in Having a Baby

Written by Lindsay Dauphinee C.N.M., M.S.N.

Hormones play a large role in pregnancy, birth and the postpartum period. Women’s bodies start to develop these hormones from the moment a pregnancy is established and they all work in conjunction with one another. In addition to facilitating labor, the perfectly timed release of hormones are also responsible for preparing for labor, determining when the body is ready for labor to start and establishing a bond between mother and baby. This part a woman’s biology is set up to ensure that labor, birth and breastfeeding all happen according to our body’s design.

Oxytocin is one of the most important hormones with multiple essential roles. Oxytocin causes rhythmic uterine contractions that help to dilate a woman’s cervix and deliver the baby. A spike in oxytocin allows for mother-baby bonding when a baby is first born, giving a new mom a feeling of love towards her new baby. It also helps to control postpartum bleeding and promote breastfeeding.

Endorphins are also hormones released during labor that help in coping with labor contractions. Along with oxytocin, endorphins create a sensation of exhilaration for the mom in the immediate postpartum period.

Another important hormone is prolactin. Prolactin begins to work in a woman’s body during pregnancy and increases right before birth. Prolactin is essential for the production of breast milk after a baby is born. Prolactin works on a supply and demand basis, and immediate skin-to-skin contact is a great way to initiate that cycle. Prolactin has also been shown to reduce anxiety and muscle tension.

It is crucial not to interfere with the natural labor process so that all of these hormones can carry out their functions properly. According to an executive summary published in Childbirth Connection*, increasing amounts of labor interventions can block the hormone cascades and all their good outcomes. Rushing a delivery, as in the case of elective induction of labor or a scheduled Cesarean Section, prevents women and their babies from getting the hormonal benefit of the physiologic onset of labor. Epidurals can diminish the effect of natural oxytocin. This can slow labor, causing the need for synthetic oxytocin and potentially contributing to interventions. Another example is separation of mother and baby after delivery. This common practice reduces oxytocin levels, and disrupts prolactin and breastfeeding. Additionally, stress can interrupt the body’s release of endorphins. A combination of all of these effects from labor interventions could do a great disservice to moms and babies.

At Inspira Midwifery Gentle Beginnings, we believe in physiologic birth and supporting a labor to take place naturally. We understand the biology of each of these hormones and respect the body’s labor process. As a practice philosophy, we try to avoid interventions whenever possible. We prioritize a calm labor environment and allow women to move freely in labor. We are committed to fostering mother-baby bonding and initiating breastfeeding with skin-to-skin contact in the immediate postpartum period. If you have questions or are interested in coming to our practice, please call us at either of our locations.

Source: “Hormonal Physiology of Childbearing”, Executive Summary by Sarah J. Buckley, Childbirth Connection, January 2015