Some Causes and Features of Vaginal Bleeding During Late Pregnancy
Cause | Common Features* | Diagnostic Approach†,‡ |
|---|---|---|
Begins with passage of a small amount of blood, sometimes mixed with mucus (mucus plug or bloody show) Uterine contractions at regular intervals plus opening (dilation) and thinning and pulling back (effacement) of the cervix | Pelvic examination and monitoring of woman's vital signs Fetal heart rate monitoring | |
Placental abruption (premature detachment of the placenta from the uterus) | Pain or tenderness when the uterus is touched Passage of dark, clotted, or bright red blood that can be light or heavy bleeding Sometimes low blood pressure in the woman, with fainting, light-headedness, or a rapid heart rate Sometimes an abnormal heart rate in the fetus | Pelvic examination and monitoring of woman's vital signs Fetal heart rate monitoring Complete blood cell count and blood tests to determine whether blood is clotting normally Often ultrasonography |
Placenta previa (an abnormally located placenta) | Painless vaginal bleeding Little or no tenderness when the uterus is touched Often, a low-lying placenta detected earlier in pregnancy on ultrasonography | Complete blood count Ultrasonography |
Vasa previa (growth of the fetus’s blood vessels across the cervix, blocking the fetus's passageway) | Painless vaginal bleeding Often signs of labor, such as contractions at regular intervals An abnormal heart rate in the fetus Sometimes, suspected based on findings during routine screening ultrasonography | Transvaginal ultrasonography using techniques to show blood flow (color Doppler ultrasonography) |
Severe abdominal pain and tenderness when the abdomen is touched Stopping of contractions and often loss of muscle tone in the uterus Baby moves back up into the birth canal Slight to moderate vaginal bleeding A slow heart rate in the fetus or no heartbeat A rapid heart rate in the woman Usually, a history of prior cesarean delivery or other uterine surgery | The doctor's suspicion, based on characteristic symptoms Emergency cesarean delivery | |
* Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present. | ||
† In pregnant women with concerning symptoms, the doctor assesses maternal vital signs, does a physical examination, and evaluates the fetus with a fetal heart rate monitor or ultrasonography. | ||
‡ Ultrasonography is typically done in women with bleeding late in pregnancy, and a complete blood cell count, blood type, and Rh status (positive or negative) are usually determined. | ||