What causes slight bleeding in the third trimester of pregnancy without abdominal pain, and what should be done?

Light bleeding without abdominal pain in the late stages of pregnancy may be caused by bloody show, cervical polyps, placenta previa, early placental abruption, or vaginitis. Symptoms can be managed through symptom observation, bed rest, medication, and medical monitoring. If bleeding increases or abdominal pain occurs, immediate medical attention is required.

1. Bloody show: In late pregnancy, cervical maturation causes separation of the fetal membranes near the internal cervical os from the uterine wall, leading to rupture of capillaries and minor bleeding. The blood is typically small in amount and appears as brownish mucus. It is recommended to record the time and amount of bleeding, rest adequately to avoid fatigue, prepare for delivery, and seek medical care promptly when regular contractions begin.

2. Cervical polyps: Hormonal changes during pregnancy can cause cervical polyps to enlarge, with fragile surface blood vessels prone to rupture and cause slight bleeding, usually without abdominal pain. Avoid sexual intercourse and strenuous activity, seek timely medical evaluation, and follow a doctor’s guidance for appropriate management if necessary.

3. Placenta previa: The placenta attaches to the lower segment of the uterus or covers the cervical os. Uterine contractions in late pregnancy may cause rupture of blood vessels at the placental edge, resulting in variable amounts of painless bleeding. Immediate bed rest is required, along with complete restriction of physical activity. Follow medical advice to use medications such as magnesium sulfate injection, ritodrine tablets, or tranexamic acid injection to manage symptoms.

4. Early placental abruption: Partial detachment of the placenta may initially present only as painless bleeding, though abdominal pain may develop later. Immediate medical evaluation is essential to monitor fetal heart rate and placental status. Follow medical instructions to use medications such as ritodrine hydrochloride injection, dexamethasone injection, or etamsylate injection to manage symptoms.

5. Vaginitis: Reduced immunity during pregnancy can disrupt vaginal flora, causing inflammation that leads to mucosal congestion and bleeding, often accompanied by abnormal discharge and itching. Under medical supervision, use medications such as clotrimazole suppositories, nifuratel-nystatin vaginal soft capsules, or Hongke antiseptic wash solution to relieve symptoms.

Maintain external genital hygiene by washing with warm water, wear loose cotton underwear and change frequently, eat a light and nutritionally balanced diet, maintain emotional stability, avoid stress and anxiety, and attend regular prenatal checkups to monitor maternal and fetal health.