Differential Diagnosis for Vaginal Spotting at 28 Weeks Gestation after Sex

• Single most likely diagnosis
  • Cervical ectropion or cervical friability: This condition is common in pregnancy due to hormonal changes and increased blood flow, making the cervix more prone to bleeding, especially after sexual intercourse.
• Other Likely diagnoses
  • Placenta previa: Although less common, placenta previa can cause vaginal bleeding during pregnancy, and sexual activity may precipitate bleeding in some cases.
  • Vaginal or cervical trauma: Sexual activity can cause minor trauma to the vagina or cervix, leading to spotting.
  • Infection (e.g., cervicitis): Infections of the cervix can cause bleeding, especially after sexual activity.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Placental abruption: This is a serious condition where the placenta separates from the uterus, and it can cause vaginal bleeding. Although it's not directly related to sexual activity, any vaginal bleeding in pregnancy warrants consideration of this diagnosis.
  • Uterine rupture (in women with a previous uterine scar): Although rare, uterine rupture is a life-threatening emergency that could potentially be triggered by sexual activity in women with a previous uterine scar.
• Rare diagnoses
  • Molar pregnancy (if not previously diagnosed): Although typically diagnosed earlier in pregnancy, a molar pregnancy could potentially cause bleeding later in gestation.
  • Uterine or cervical malignancy: Cancer of the uterus or cervix is rare in pregnancy but could cause abnormal vaginal bleeding.
  • Vasa previa: A condition where fetal blood vessels are exposed in the lower uterine segment, which can cause significant bleeding if ruptured, potentially during sexual activity.