- Prolactin – prolactin is the hormone responsible for milk production, so for moms who elect to breastfeed, this hormone remains persistently elevated. Prolactin generally leads to feelings of relaxation and calm, but it directly counteracts dopamine, which plays a big role in sexual arousal and gratification. Thus, you can feel pretty serene while you’re breastfeeding, but you might be so content that you don’t care about having sex.
- Oxytocin – during breastfeeding, this hormone increases and causes milk letdown and release. It’s also associated with bonding both with breastfeeding and sex. During intercourse, it’s released during orgasm, so it’s not uncommon for milk leakage to happen during sex. Depending on the amount of leakage that happens, some women can become a bit self-conscious, and in turn, this can decrease desire for intercourse.
- Estrogen – estrogen will be low for at least the first several months after delivery, and it may continue to be low throughout breastfeeding. Low estrogen can cause menopausal-type changes within the vagina, leading to decreased lubrication and elasticity with increased tightness, which, in turn, can cause painful intercourse. That drop in estrogen after delivery also plays a big role in postpartum hair loss. While this should resolve in few months to year and typically only involves catching up with the normal loss that doesn’t happen during pregnancy, for some women the sudden large amounts of hair loss can be pretty traumatic. Be sure to continue prenatal vitamins, use gentle brushing and hair car techniques, and remember that this change should be temporary.
- Testosterone – this hormone plays a role in libido/desire, and it is suppressed in the postpartum period and with breastfeeding.
- FSH – this hormone is responsible for menstrual cycle regulation, and while levels don’t change much during the postpartum period and breastfeeding, it’s level of activity can. Change in FSH activity may contribute to anovulation (not releasing an egg). While change in FSH activity can be helpful in preventing pregnancy for some women (some women can still get pregnant while breastfeeding), it can also be a culprit for some pretty erratic bleeding. Both menstrual and nonmenstrual bleeding can be very unpredictable for women while breastfeeding, with cycles ranging from completely absent to dysfunctional bleeding nearly every day. The same irregularity can be present with fertility while breastfeeding as well, with some women who don’t ovulate and can’t get pregnant to those with resumption of normal cycles and fertility to those who become pregnant even before they have their first menstrual cycle after their baby is born.