Estrogen While Breastfeeding
During pregnancy, circulating levels of the sex hormones estrogen and progesterone rise to prepare your body for lactation. After you give birth, however, levels of these hormones drop as your body increases production of prolactin. As levels of this lactation-inducing hormone increase with decreasing estrogen levels, high estrogen levels after you give birth may make it difficult for you to breastfeed your baby.
Estrogen and Prolactin
In a typical pregnancy, estrogen levels rise to promote the development of milk ducts in your breasts. While high estrogen levels help to prevent you from lactating during your pregnancy, they also trigger the production of prolactin to prepare you for lactation after giving birth. Once prolactin levels reach a certain point, they prevent the ongoing production of estrogen. As such, estrogen levels typically drop toward the end of your pregnancy as prolactin levels rise, allowing you to breastfeed normally after you give birth.
Estrogen Dominance
While they typically drop after you give birth, estrogen levels may remain high despite your body's boost in prolactin production. This may be due to a condition known as estrogen dominance, which involves high levels of estrogen and low levels of progesterone. As these high levels of estrogen mimic those of pregnancy, your body may continue to behave as though pregnant after your body's birth. As such, estrogen dominance may block prolactin's milk-producing abilities, potentially preventing you from lactating after you give birth.
Causes
High estrogen levels following pregnancy may arise from exposure to external sources of estrogen or estrogen-like chemicals. These may include hormone-replacement therapies, petrochemicals and solvents, which may be present in cleaning products, cosmetics, soaps and shampoos. Antibiotics, pesticides and growth hormones present in commercially farmed animal products and produce may also contribute to high estrogen levels, because these products can disrupt natural changes in hormone balance. Other causes may include obesity or excess body fat, high fat intake, liver disease, high alcohol consumption, magnesium and vitamin B6 deficiencies, and stress. This decrease in estrogen can have many effects:
Absent periods—When ovulation is blocked, a woman will not get normal periods. Don’t be alarmed: many women love this “side effect” of nursing! In fact, some women use what is called lactational amenorrhea (LAM) as a form of birth control, but it is important that certain criteria are met for it to be considered effective.
This lack of periods, or very irregular ones, may not be welcome if a woman is nursing and trying to conceive. If this is the case for you, be sure to discuss it with your doctor or midwife.
Vaginal dryness—Normal estrogen levels are what help maintain the tissues of the vagina. The low levels seen in breastfeeding can mimic the decreased hormone levels seen in menopause and can result in the same kind of thinning of the skin and increased vaginal dryness postmenopausal women sometimes experience. This may make sex uncomfortable and lead to small tears during intercourse.
Decreased libido—It is hard to test out if decreased libido is truly related to breastfeeding or to the fact that having a newborn and the subsequent sleep deprivation might leave little time (or desire) for intimacy! Some studies have shown that formula-feeding moms tend to have sex sooner, while others have shown the opposite. Therefore, it’s hard to say how breastfeeding really plays into this. Some nursing moms will not want their breasts touched during sex, or may be embarrassed if they leak milk (the same hormone responsible for milk let-down—oxytocin—also plays a role in orgasm). The bottom line is that open lines of communication are important, and weaning should not be suggested as a cure-all to a subpar post-baby sex life.
Treatments
Regular exercise may help to lower your estrogen levels by lowering stress and body fat, potentially reducing complications that may arise when trying to breastfeed. Reducing your fat and alcohol intake, eating more foods rich in vitamin B6 and magnesium, and replacing commercially-produced food with organically farmed products may also help to reduce post-delivery estrogen levels. Because these lifestyle changes may not have immediate effects, the use of an anti-estrogen drug, such as the steroid clomiphene, may help to quickly reduce estrogen levels and allow you to breastfeed properly.