When a woman is pregnant, the hormones her body makes can increase her risk of experiencing a blood clot. Other factors might increase this risk further.

As technology progresses, researchers must learn both the benefits and risks that new medical procedures offer. Using in vitro fertilization ( IVF ) to have a baby is one such technology.

Pregnant women are at higher risk for blood clots, which can be fatal. Doctors use ultrasound tests to look for clots, but it's not clear whether those tests are good enough.

Some people's immune systems produce antibodies that fight parts of their own bodies. These aren’t always a big deal. But sometimes they can contribute to stroke or miscarriage risk.