People say a lot of things about what does and does not cause miscarriages, and a lot of it can be confusing. Even doctors don't give the same information on a lot of issues. For example, one person might tell you that stress can cause miscarriages, but then another might claim that to be a myth.
The truth is usually somewhere in the middle. The following are common claims that are out there about miscarriage causes and risk factors. Before you get started, it helps to read up on the difference between a cause and a risk factor.
Truth: There could be a grain of truth to this one. There are studies that have found an increased risk of miscarriage in women who had terminated a pregnancy. But the evidence is mixed, and any theoretical increased risk might be limited to women who had an abortion via D & C.
Truth: This might be true. There have been several studies in recent years that found evidence of a link between stress and miscarriage or stillbirth, although the evidence doesn't prove that the stress is what caused the miscarriages in those cases. If there is a link between stress and miscarriages, it's not likely that average amounts of stress would play a role in miscarriage, but more that unusual or chronic stress might be a factor.
Truth: There is evidence that using non-steroidal anti-inflammatory drugs can increase risk of miscarriage, but the evidence on aspirin is mixed -- and some doctors even prescribe low dose aspirin as a part of recurrent miscarriage treatment.
Truth: Although taking a large dose of birth control pills within a few days of intercourse can work as emergency contraception, there is no evidence that birth control pills will cause a miscarriage in an established pregnancy or that taking birth control pills will increase risk of future miscarriage.
Truth: No one knows for sure. There was a large study in 2007 that indicated women who engaged in strenuous exercise were more likely to have miscarriages, but there have been other studies that found no link between exercise and miscarriage. Light and moderate exercise during pregnancy are almost certainly beneficial. Some doctors advise keeping your heart rate under 140 beats per minute to be on the safe side.
Truth: This is partially true. There is a risk of miscarriage if you contract food poisoning from listeriosis, salmonella, or toxoplasmosis during pregnancy -- and you can be more likely to get sick with food poisoning when you're pregnant. But you don't have to avoid all cheese or deli meats; you just have to choose pasteurized dairy products or meats that have been thoroughly cooked.
Truth: There's no evidence that sex during pregnancy poses any risk. Sex doesn't even seem to be able to trigger labor in women with full-term pregnancies, so you should definitely not worry about orgasms or uterine contractions causing miscarriage. There are a few exceptions, however, such as women with a condition called placenta previa.