There are many reasons for vaginal bleeding in pregnancy. While many are nothing to worry about, others are quite serious and require a doctor's immediate attention. Pregnant women should educate themselves about the various causes of early and late abnormal bleeding so they can determine when emergency medical help is necessary.
Miscarriage
Of the 20 to 30 percent of pregnant women who experience bleeding, only 15 to 20 percent of these result in miscarriage, according to the American Pregnancy website. The majority of all miscarriages occur during the first trimester. Signs of miscarriage include bleeding accompanied by menstrual-like cramps and lower back pain, along with tissue discharge that may be clumpy.
Ectopic Pregnancy
An ectopic pregnancy occurs when a fertilized egg implants outside the uterus during its journey down the fallopian tube. Ectopic pregnancies are less common than miscarriages, according to the American Congress of Obstetricians and Gynecologists, and occur in approximately one in 60 pregnancies.
Signs of an ectopic pregnancy include vaginal bleeding together with lower abdominal cramps that resemble strong menstrual cramps, and sharp abdominal pains. Women with a fallopian tube infection, a history of pelvic surgery or previous ectopic pregnancy, are at greater risk for this type of pregnancy occurring.
Molar Pregnancy
Molar pregnancies are a rare cause of early bleeding, and are essentially a cluster of abnormal tissue that forms in lieu of an embryo. In addition to vaginal bleeding, American Pregnancy says other molar pregnancy symptoms get diagnosed at a doctor's office. They include the absence of a fetal heartbeat, high HcG levels, and grape-like clusters in the uterus that can be seen on ultrasound.
Problems with the Placenta
During the second and third trimester, heavy bleeding often involves a problem with the placenta, according to the American Pregnancy website. Placental abruption occurs when the placenta detaches from the uterine wall before of during labor. Pain and bleeding usually ensue. Occurring in just once percent of pregnant women, this rare condition usually occurs during the last trimester and can affect the baby's ability to get oxygen in utero. Women older than age 35, those with sickle cell anemia, or women with a history of placental abruption, have an elevated chance of it occurring again.
Placenta previa occurs when the placenta partially or fully covers the cervix. A telltale sign of this condition, according to the American Congress of Obstetricians and Gynecologists, is painless vaginal bleeding. Occurring in one in 200 pregnancies, placenta previa is more common in women who have had a previous cesarean birth or uterine surgery, have other children, or who have a pregnancy with multiples. Placenta previa is a serious condition that requires immediate medical attention.
Labor and Pre-Term Labor
Late in pregnancy, vaginal bleeding is often an indication of labor caused by the passing of the bloody mucus plug from the cervix. Losing the mucus plug is only a concern if it happens earlier than 37 weeks of pregnancy.
Preterm labor is any bleeding accompanied by discharge, regular contractions, and a lower backache before 37 weeks of pregnancy. When this occurs, pregnant women should call their doctor immediately. According to the American Congress of Obstetricians and Gynecologists, conditions that cause bleeding late in pregnancy pose risk to both mother and fetus, and may require a premature delivery.
