What causes bleeding after intercourse during the second trimester of pregnancy?

Generally, bleeding after intercourse during the second trimester of pregnancy may be caused by vaginal mucosal injury, cervical congestion, vaginitis, cervicitis, placenta previa, or other reasons. It is recommended to seek medical attention promptly, identify the underlying cause, and receive symptomatic treatment under a doctor's guidance. Specific analysis is as follows:

1. Vaginal Mucosal Injury: Excessive force or improper positions during intercourse can easily cause minor tears in the vaginal mucosa, leading to slight bleeding. Avoid sexual intercourse temporarily, maintain good external genital hygiene, wear loose and breathable cotton underwear; recovery usually occurs spontaneously within a few days.

2. Cervical Congestion: During mid-pregnancy, increased blood flow and softer, more fragile cervical tissue make the cervix prone to capillary rupture and bleeding following sexual stimulation. Reduce frequency of intercourse, use gentle movements, avoid excessive cervical stimulation, and clean the external genital area daily with warm water only.

3. Vaginitis: Hormonal changes during pregnancy reduce vaginal resistance, making it susceptible to bacterial or fungal infections that trigger inflammation. Inflamed mucosa may bleed after intercourse, often accompanied by itching and abnormal discharge. Treatments such as nitrofurantoin-miconazole vaginal soft capsules, clotrimazole suppositories, or metronidazole vaginal effervescent tablets may be used according to medical advice.

4. Cervicitis: Infection of the cervix by pathogens causes inflammation, resulting in redness, swelling, and congestion of the cervical mucosa, which may lead to post-coital bleeding, along with increased discharge and foul odor. Treatment may include azithromycin capsules, cefixime dispersible tablets, or doxycycline hydrochloride tablets under a doctor’s supervision.

5. Placenta Previa: When the placenta is implanted too low and covers the cervical opening, intercourse may compress the placenta and cause rupture of its blood vessels, resulting in potentially heavy bleeding. Sexual activity should be stopped immediately, bed rest is required, and medications such as progesterone soft capsules, magnesium sulfate injection, or ritodrine tablets should be administered per medical instructions to suppress contractions and preserve the pregnancy.

During the second trimester, intercourse should be performed gently and infrequently, using mild positions that avoid abdominal pressure. Monitor vaginal discharge regularly, maintain genital hygiene, avoid tub baths and douching to reduce the risk of infection.