Marfan syndrome Marfan syndrome is a birth defect that affects the body's connective tissue. Learn the signs and symptoms of Marfan syndrome and how it's treated.
Rh disease RH factor is a protein on some people's red blood cells. Learn how RH disease affects your baby and how to prevent it.
Smoking during pregnancy Smoking during pregnancy can cause problems like premature birth and birth defects. If you need help to quit smoking, tell your health care provider.