Can I prevent a miscarriage?

Miscarriages are extremely common. Approximately 1 in 5 pregnancies will end in miscarriage. Many women wonder if there is anything they can do to prevent a miscarriage. For the vast majority of miscarriages, there is nothing you can do to prevent it from happening.

Most miscarriages are caused by one time, non-repeating genetic defects in the embryo. The egg might be abnormal, the sperm might be abnormal or the combination might be abnormal. This does not mean that either you or your partner has a genetic defect. Every woman has some abnormal eggs and every man produces some abnormal sperm.

An embryo that has one of these one time, non-repeating genetic defects is destined to miscarry from the moment of conception. That’s why there is nothing that you can do to prevent the miscarriage. At some point, the embryo will stop growing and developing and be expelled by your body.

If you’ve had a miscarriage, you don’t have to wonder if you did anything to cause it. Nothing you can do can cause a miscarriage. It is true that doctors sometimes recommend bed rest for women who have bleeding in early pregnancy. However, all medical studies show that bed test cannot prevent a miscarriage.

There is a small group of miscarriages that can be prevented. These miscarriages are causes by a progesterone deficiency (luteal phase defect). Progesterone is needed to support the growth of a pregnancy. In the early weeks of pregnancy, the mother’s body produces the progesterone. By about 8-9 weeks of pregnancy, the placenta usually takes over the production of progesterone. Women who don’t produce enough progesterone in the early weeks of pregnancy may have repeated miscarriages. These miscarriages can be prevented by progesterone supplements.

Only a small percentage of women have a progesterone deficiency. The most common symptom of progesterone deficiency is a menstrual cycle that is less than 26-27 days long. A progesterone deficiency can be diagnosed by tests done before you get pregnant. Women who do not have a progesterone deficiency will not benefit from progesterone supplements.

Measuring progesterone levels at the beginning of pregnancy may show dropping levels of progesterone before a miscarriage. However, it seems more likely that levels drop because the pregnancy is no longer growing, not because the dropping levels cause the miscarriage. Therefore, taking progesterone supplements will not prevent the miscarriage.

The bottom line is that in the vast majority of miscarriages, you could not have caused the miscarriage, and you could not have prevented it.