The following guidelines will help you determine the severity of your vaginal bleeding.

• Severe bleeding: You have continuous bleeding that soaks through your usual pad each hour for 2 or more hours. Note: A pregnant woman may have a gush of blood or pass a clot, but if the bleeding stops, it is not considered severe.
• Moderate bleeding: You soak more than 1 pad in 3 hours.
• Mild bleeding: You soak less than 1 pad in more than 3 hours.
• Minimal bleeding: You have "spotting" or just a few drops of blood from the vagina.

Vaginal bleeding can be a sign of miscarriage or premature labor during pregnancy in the first trimester. During the first trimester of pregnancy:

• Up to 25% of pregnant women have some spotting or light vaginal bleeding. Of these women, about 50% do not have a miscarriage. Vaginal bleeding during pregnancy is more common among women who have been pregnant before than in women who are pregnant for the first time.
• Very early spotting sometimes occurs when the fertilized egg implants in the uterus. Implantation takes place 6 to 10 days after fertilization, which usually occurs on the day of intercourse.

Bleeding in the second or third trimester of pregnancy may mean a problem is present, such as:

• Placenta previa. Normally, the placenta is attached to the top portion of the uterus. In less than 1% of all pregnancies, the placenta has attached low in the uterus, and partially or completely covers the cervix. This blockage of the cervix is called placenta previa.
• Placenta abruptio. Normally, the placenta is firmly attached to the uterine wall until birth. In about 1% of all pregnancies, the placenta separates from the uterus before the baby is delivered. This separation is called placenta abruptio or abruptio placenta or placental abruption. Placenta abruptio usually occurs in the third trimester of pregnancy, but it can occur any time after the 20th week.