What causes bleeding due to contractions during the second trimester of pregnancy, and what should be done?

Generally, bleeding caused by uterine contractions during the second trimester of pregnancy is due to conditions such as placenta previa, placental abruption, cervical insufficiency, cervicitis, or cervical polyps. This can be treated through general therapy, medication, and other approaches. If experiencing any physical discomfort, prompt medical attention is recommended. Detailed explanations are as follows:

1. Placenta Previa

When the uterus contracts, the lower segment of the uterus gradually stretches, but the placenta attached to the lower segment or the internal cervical os cannot stretch correspondingly. This mismatch can cause displacement between the placenta and the uterine wall, leading to rupture of capillaries at the placental edge and subsequent bleeding. Typically, no specific treatment is required. It is recommended to rest in bed as much as possible and avoid strenuous activity and sexual intercourse.

2. Placental Abruption

Placental abruption can be caused by external abdominal trauma or maternal conditions such as gestational hypertension. During uterine contractions, the separation between the placenta and the uterine wall may worsen, causing blood vessels at the abruption site to rupture and bleed. It is often accompanied by significant abdominal pain. Treatment may include medications such as amoxicillin capsules, tranexamic acid tablets, and progesterone capsules under a doctor's guidance.

3. Cervical Insufficiency

Cervical insufficiency may result from congenital underdevelopment or acquired damage. When uterine contractions occur, pressure is transmitted to the cervix. Due to cervical insufficiency, the cervical opening may gradually dilate, making the capillaries in the cervical mucosa prone to rupture and causing bleeding. The bleeding is typically light red or dark red in color. Medications such as nifedipine sustained-release tablets, ritodrine hydrochloride tablets, and dydrogesterone tablets may be used under medical supervision.

4. Cervicitis

Cervicitis is usually caused by cervical injury and infection with pathogens. Inflammation causes the cervical mucosa to become congested and edematous. When uterine contractions occur, the cervix is stimulated, making the congested mucosal blood vessels prone to rupture and bleeding. Treatment may include medications such as roxithromycin dispersible tablets, azithromycin tablets, and traditional Chinese medicine like Fuke Qianjin tablets, following a doctor's instructions.

5. Cervical Polyps

Cervical polyps are benign growths formed by localized hyperplasia of the cervical mucosa. Uterine contractions may cause the surface blood vessels of the polyp to rupture, leading to vaginal bleeding. The blood is typically bright red in color. Treatment may involve medications such as cefuroxime axetil capsules, ribavirin capsules, and ibuprofen sustained-release tablets, following a doctor's advice.

In daily life, pregnant women should maintain a light and healthy diet, consume nutritious foods, and seek timely medical care for any discomfort to avoid delaying treatment.