Pregnancy Bleeding - First Trimester

Vaginal bleeding during pregnancy is a scary thing - regardless the cause. Vaginal bleeding is any bleeding coming from the vagina but usually refers to abnormal bleeding that is not associated with a regular menstrual period.

First Trimester Bleeding

First trimester bleeding is considered to be any bleeding that occurs during the first three months of gestation. It may vary from light spotting to heavy bleeding complete with clots. It occurs commonly in early pregnancies, causing complications in 20 to 30 percent of all pregnancies. Sometimes a woman will have light bleeding during the first month of her pregnancy, after conception. It is nothing to be very worried about, but it still causes concern. Often it is implantation bleeding and occurs about the time her normal menstrual cycle would start.

Second and Third Trimester Bleeding

Second and third trimester bleeding (from the third month to the end of pregnancy) has concerns other than what are involved in first trimester bleeding. Any type of bleeding in this period is considered to be abnormal and cause for concern. If bleeding occurs after the 28^th week of pregnancy, it is a serious concern and an emergency in the true sense of the word. Whether very mild or extremely intense, accompanied by abdominal pain or not, bleeding at this point is dangerous. Hemorrhage complicates four percent of all pregnancies and is the most common cause of death in mothers at this stage in the US.

Blighted Ovum

Along with the implantation bleeding and postcoital bleeding in the first trimester, there are other causes of bleeding. Blighted ovum, also called an embryonic failure, is when the embryo fails to develop as it should in the proper location in the uterus. If the embryo or fetus is abnormal in some way, this is often the result. It isn't anybody's fault and it isn't anything you did or didn't do - it just is.

Intrauterine Fetal Demise

Intrauterine fetal demise (IUFD) can occur at any point in a pregnancy, however, it often happens in the first trimester. An ultrasound confirms the diagnosis. The reasons for an IUFD are essentially the same as they are for a threatened miscarriage that occurs during the early stages of pregnancy. It is uncommon for IUFD to occur past the first trimester. However, if it does occur later, it includes placental separation from the uterine wall (placenta abruption) or happens because the placenta didn't receive enough blood flow.

Ectopic Pregnancy

Ectopic pregnancy, also referred to as tubal pregnancy, is another reason for first trimester bleeding. This type of bleeding is very dangerous and occurs as a result of the fertilized egg implanting in the fallopian tube. There isn't room for the baby to grow in such a small space and as a result it can rupture the tube, causing life-threatening bleeding. Most frequently the pregnancy ends before the 10^th week. The fetus cannot develop and will die because of the lack of nutrients. Ectopic pregnancy occurs in about three percent of all pregnancies.

There are definite risk factors for ectopic pregnancy, including:

· history of a prior ectopic pregnancy

· history of pelvic inflammatory disease (PID)

· history of Fallopian tube surgery or ligation

· history of infertility for more than two years

· having an IUD (intrauterine device) in place

· smoking

· frequent (daily) douching

Nearly half of all women who experience an ectopic pregnancy have risk factors - the other half does not.

Molar Pregnancy

A molar pregnancy, technically called gestational trophoblastic disease, is evidenced by an ultrasound that shows the presence of abnormal tissue inside the uterus rather than a developing fetus. Actually, this is a type of tumor that is a result of the hormones present during pregnancy and is not usually life threatening. In rare cases, the tumor is malignant and can potentially penetrate the uterine wall and spread to other parts of the body. The cause of molar pregnancies is unknown.

First trimester bleeding can be caused by reasons that are not related to pregnancy. Trauma or tears to the vaginal wall can cause bleeding as can some infections.

To learn more about pregnancy bleeding, see our article in this section.