Vaginal bleeding in pregnancy is bleeding coming through the vagina during pregnancy, for any reason.

Up to 10% of women have vaginal bleeding at some time during their pregnancy, especially in the first trimester (first 3 months). Bleeding is even more common with twins.

To help prevent a miscarriage or other problems during pregnancy, avoid smoking and the use of drugs of any kind, including alcohol. Eat a well-balanced diet, and obtain regular medical checkups.

Any vaginal bleeding at any point in pregnancy should always be reported to your doctor.

Vaginal bleeding during the first 3 months of pregnancy may be an indication of a spontaneous abortion (miscarriage). See the doctor immediately.

Vaginal bleeding during the fourth to ninth month of pregnancy may be caused by a miscarriage, but may also be an indication of abnormal location of the placenta, such as placenta previa or abruptio placentae.

An ectopic pregnancy, in which the embryo becomes implanted outside the uterus, is often accompanied by unexpected vaginal bleeding and severe abdominal pain. Ectopic pregnancy is sometimes associated with current use of an IUD.

A cervical infection can cause bleeding at any time, including during pregnancy.

Trauma to the cervix from intercourse may cause a small amount of bleeding.

Early labor is sometimes accompanied by a small amount of bleeding (bloody show).

There may be other causes of vaginal bleeding in pregnancy. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of vaginal bleeding during pregnancy can include other diseases and medications. The causes may be different depending on the age of the woman. Specific characteristics of this symptom can indicate its different causes. Such characteristics  include quality (light or heavy bleeding, with or without pain), length of bleeding, aggravating factors (what makes the bleeding worse), relieving factors (what makes it better), and related complaints.

Any bleeding during pregnancy should be evaluated by your health care provider. For a threatened miscarriage, follow the doctor's orders. Medication is usually not necessary -- don't take any medication without consulting the doctor. Avoid sexual intercourse until the outcome of the bleeding is known. Drink only fluids if the bleeding and cramping is severe.

If a miscarriage occurs, expect a small amount of vaginal bleeding for up to 10 days. Avoid using tampons for 2 to 4 weeks. For vaginal bleeding caused by placenta previa, get to the hospital immediately. Bed rest in the hospital, at least until bleeding stops, is mandatory, and a cesarean section is likely if it is close to the delivery date, or if the bleeding persists.

For bleeding caused by an ectopic pregnancy, surgery or medical treatment to remove the growing embryo and control internal bleeding is likely to be needed.

Vaginal or cervical infection is treated with antibiotics that are safe for a developing fetus.