Hormones Of Labor and Birth
Hormones play an essential role throughout labor and birth. By understanding how these hormones function during a natural birth, women can learn how to work with them when they are in labor. At the same time, women can make more informed decisions with their healthcare professionals about medical interventions that can disrupt the natural role of hormones.
Although many hormones are involved in human reproduction, oxytocin, endorphins, and adrenaline are the main types of hormones that play a key role in labor and birth.
Known as the hormone of love, oxytocin is secreted during lovemaking; after ovulation; and during labor, birth, and breastfeeding. It creates nurturing and loving feelings.
During labor, oxytocin stimulates contractions. As each contraction occurs, the pain signals the brain to release more oxytocin, which then increases the contractions. The release of oxytocin and the rhythmic contractions of labor facilitate cervical dilation, delivery of the baby, and the expulsion of the placenta.
The baby also produces oxytocin during an unmedicated labor. Right after birth, both mother and baby experience the positive effects of oxytocin, which is further enhanced by skin-to-skin contact, eye contact, and the initiation of breastfeeding.
Produced in response to pain and stress, endorphins have calming and pain-relieving effects. As labor progresses and pain intensifies, endorphin levels steadily increase in unmedicated labors. Endorphins have natural morphinelike effects, decreasing the perception of pain and creating an altered state of consciousness. As a result, a woman in labor shifts to a more instinctive mindset, which facilitates her ability to cope with the birth process. She is able to “go into the zone” and focus on the work of labor. After labor, high endorphin levels can help a woman feel alert and attentive as she greets her newborn and initiates breastfeeding.
Known as the “fight or flight” hormone, adrenaline is secreted in response to stress, fear, and extreme pain. If a woman feels threatened during labor, such as by fear or extreme pain, she may produce too much adrenaline, which can impede labor. In a natural birth right before delivery, a surge of adrenaline provides the woman with a rush of energy, stimulating contractions and activating the fetal ejection reflex. At birth, high adrenaline levels allow the baby to be wide-eyed and alert when meeting the mother for the first time and helping in the initiation of breastfeeding.
Medical interventions, such as induction and augmentation of labor and the use of pain medications, can interfere with the natural hormonal processes of giving birth. These procedures can sometimes lead to a cascade of interventions that can result in a cesarean birth. By understanding the natural birth process, a woman can work with her healthcare professional to make informed decisions that best fit her situation and childbirth preferences.