Estrogen is the talk of the town in women’s circles. From the mood swings to the feminine features, estrogen takes the stage by storm. And during menopause, who do women miss the most? Estrogen, of course. But when we are talking about pregnancy, a second female hormone becomes the boss: progesterone.
Both estrogen and progesterone are produced primarily by the ovaries, and their monthly rhythmic rise and fall orchestrate women’s menstrual cycles. Estrogen promotes cell division. In contrast, progesterone inhibits cell division but promotes cell maturation. Thus, during the menstrual cycle, estrogen first builds up the lining of the uterus. Once the uterine lining is thick enough, progesterone matures the lining so that it can sustain fetal implantation. In other words, estrogen builds the house, and estrogen takes care of the furnishings to make the lining suitable for the survival of the fetus. So in truth, both are essential for a successful pregnancy. [Note: menstruation is caused by the drop in progesterone and the resultant breakdown of the uterine lining]
However, progesterone is called the “pregnancy hormone” because of two pregnancy-sustaining functions:
· Once the fetus implants on the lining of the uterus, progesterone prevents the immune system of the mother from attacking the fetus, which can be considered by the maternal immune system as “foreign.”
· Progesterone also relaxes smooth muscles, including the muscles of the uterus (the ones that contract during menstrual cramps). This is so that the fetus and uterine lining are not expelled.
· However, while progesterone inhibits milk production by the breasts, it does help the cells of the mammary glands mature to be able to perform their life-giving function after birth.
Not all peachy
Unfortunately, it is also because of some of the effects of pregnancy that women suffer from the many pregnancy-associated ills and discomforts. First of all, progesterone relaxes not just the muscles of the uterus but also the muscles of the gut. Because of this, pregnant women commonly suffer from indigestion, heartburn, bloatedness, and constipation—all because of gut sluggishness caused by progesterone.
Oftentimes, progesterone can also soften cartilage and loosen joints and cartilages. That’s why during the third trimester, many women complain of aches and pains in the hips and pelvis. No, it’s not just the weight of the baby bearing on your hips, but also because of progesterone.
Lastly, through mechanisms that are still not very clear, progesterone seems to play a role in gum swelling and gum bleeding, which are common afflictions of pregnant women.
Low on progesterone?
Many women who have difficulty becoming pregnant or carrying a pregnancy to term may have low progesterone to blame, at least partly. Many women have repeated miscarriages because of low progesterone levels. Low progesterone levels means poor inhibition of uterine contractions. For these women, progesterone-like medications are sometimes given to help relax the uterus and carry the pregnancy to term. A similar strategy is also used to stop preterm labor.
Additionally, some women have menstrual disorders as a result of low levels of progesterone. In these cases, the ovaries do not produce enough progesterone. Because menstruation is caused by the drop in progesterone, menstruation does not happen in these women because progesterone never rose in the first place. For these women, obstetricians may at times attempt to induce menstruation by giving progesterone, and then stopping it after a couple of days.
Other uses of progesterone
Some studies suggest that estrogen replacement therapy may increase the risk of disorders of the uterine lining, such as abnormal uterine bleeding or endometrial cancer. Thus, for menopausal women on estrogen replacement therapy, progesterone replacement therapy may also be recommended to counter these adverse effects of estrogen in the context that progesterone can regulate the effects of estrogen.
Just like normal uterine lining tissue, endometriosis proliferates as a response to estrogen exposure. And so, during menstruation, these tufts of tissues may also “bleed” inside the pelvis, causing recurrent pelvic pain, dysmenorrhea, or even infertility. Progesterone may be used to inhibit the effects of estrogen on these abnormal tissues.
You and progesterone
All in all, progesterone is very much as important as estrogen to women and their health. It helps prepare for pregnancy, and helps carry the pregnancy through. It regulates your mood, and tempers the effects of estrogen. It is also a useful treatment for a number of reproductive or infertility problems.
All hail progesterone!