During pregnancy, having a medical condition can increase the risk of pregnancy complications for the pregnant woman or the fetus. The disorder may be one that
A woman had before she became pregnant (preexisting disorders)
Develops during the pregnancy but is not directly related to the pregnancy
Diabetes and high blood pressure are examples of preexisting disorders that increase the risk of health problems during pregnancy. If women have such a disorder and wish to become pregnant, they should first talk with a doctor and take any steps necessary to manage the disorder as well as possible before they become pregnant. Once women with medical conditions become pregnant, they may need special care, often from a team of medical specialists. The team may include an obstetrician (who may also be a specialist in care of the disorder during pregnancy), a specialist in the disorder, and other health care professionals (such as nutritionists).
Sometimes disorders that are not directly related to pregnancy develop during pregnancy. Some of them increase the risk of problems for the pregnant woman or the fetus. They include disorders that
Affect the blood flow to the placenta
Increase the risk of forming blood clots
Are infections that can cause severe illness or fetal abnormalities
Involve something in the pregnant woman's blood that can pass through the placenta and harm the fetus
Some disorders are more likely to occur during pregnancy because of the many changes pregnancy causes in a woman’s body. Examples are
Blood clots in the legs or lungs (thromboembolic disorders)