Merck Manual

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Some Causes and Features of Vaginal Bleeding During Late Pregnancy

Some Causes and Features of Vaginal Bleeding During Late Pregnancy

Cause

Common Features*

Tests

Passage of a discharge containing a small amount of blood mixed with mucus (bloody show) and no further bleeding

Contractions in the lower abdomen at regular intervals plus opening (dilation) and thinning and pulling back (effacement) of the cervix

Other typical signs of labor

A doctor's examination

Sometimes ultrasonography

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 but sometimes only slight bleeding

Sometimes low blood pressure in the woman, with fainting, light-headedness, or a racing heart

An abnormal heart rate in the fetus

A doctor’s examination

Ultrasonography

Placenta previa (an abnormally located placenta)

Painless vaginal bleeding with bright red blood

Little or no tenderness when the uterus is touched

Routine ultrasonography or transvaginal ultrasonography (using an ultrasound device inserted into the vagina) by an experienced practitioner

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

Routine ultrasonography or 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

Slight to moderate vaginal bleeding

A doctor’s examination

Laparotomy (surgery involving an incision into the abdomen)

*Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

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.