A miscarriage is a pregnancy loss that occurs within the first 20 weeks of pregnancy. It is estimated that 10 to 15 percent of women who know that they are pregnant will suffer a miscarriage. That number may be much higher, given that many women have early miscarriages before they ever know that they are pregnant. Miscarriages that occur in the early stages of pregnancy may be the result of hormonal problems.
Function of Pregnancy Hormones
Pregnancy hormones are responsible for maintaining a healthy pregnancy and growing a healthy baby. Until about week 10 of pregnancy, pregnancy hormones are produced by the ovaries. After that, the placenta takes over producing them. When the ovaries or the placenta do not produce the right amount of hormones needed to maintain a pregnancy, miscarriage can occur.
Pregnancy Hormones Associated with Miscarriage
While there are many hormones involved with pregnancy, there are two hormones that are most often associated with miscarriage. These hormones include progesterone, which maintains the pregnancy until the baby’s birth, and human chorionic gonadotropin (hCG), which supports the pregnancy by ensuring that the ovaries produce the proper levels of progesterone until the placenta takes over its production.
Hormone Levels Needed to Maintain a Pregnancy
Human chorionic gonadotropin is the hormone that is detected in a positive pregnancy test. In non-pregnant women, the level of hCG is less than 5.0 mIU/ml. After implantation occurs, hCG should rise and double every 48 to 72 hours. During pregnancy, hCG can range from 5 mIU/ml to 288,000 mIU/ml. Human chorionic gonadotropin levels peak at around 12 weeks, and then decline and maintain at a lower level for the remainder of the pregnancy. According to the American Pregnancy Association, during pregnancy, progesterone levels should fall between 9 to 47 ng/ml during the first trimester, 17 to 146 ng/ml during the second trimester, and 49 to 300 ng/ml during the third trimester.
The levels of both hCG and progesterone can vary from woman to woman and pregnancy to pregnancy. Low hormone levels can indicate a problem with the health of a pregnancy that may result in miscarriage. While hCG levels can indicate the viability of a pregnancy, a single number alone cannot be used to determine the health of a pregnancy. Low levels of hCG could represent that a pregnancy isn’t as far along as suspected. When using hCG to gauge the health of a pregnancy, how much the levels increase over time must be considered. Doctors monitoring hCG levels will often compare hCG levels taken over the course of several days.
Since there is no harm to the pregnancy when additional progesterone is introduced, progesterone supplements can be used to increase the level of progesterone, which may help prevent miscarriage. While there is synthetic and natural progesterone available, natural progesterone is the same hormone that a pregnant woman’s ovaries produce. Natural progesterone is available in oral preparations, but since it isn’t absorbed well when taken orally, it’s most often given by injection, vaginal suppository or gel application.