Differential Diagnosis for Spotting in Pregnancy at 26 Weeks

• Single most likely diagnosis
  • Placenta previa: This condition, where the placenta partially or completely covers the cervix, is a common cause of spotting in the second and third trimesters of pregnancy. The risk increases with gestational age, making it a likely consideration at 26 weeks.
• Other Likely diagnoses
  • Cervical polyps or cervical lesions: These can cause spotting due to the increased blood flow and sensitivity of the cervix during pregnancy.
  • Vaginal or cervical infections: Infections such as bacterial vaginosis or cervicitis can lead to spotting.
  • Sexual intercourse: Spotting can occur after sexual activity due to the increased blood flow to the cervix and vagina during pregnancy.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Placental abruption: Although less common than placenta previa, placental abruption (where the placenta separates from the uterus) is a life-threatening condition for both the mother and the fetus, requiring immediate medical attention.
  • Uterine rupture: This rare but potentially catastrophic event can occur in women with a history of uterine surgery, including cesarean deliveries, and can present with spotting along with severe abdominal pain.
• Rare diagnoses
  • Molar pregnancy complications: Although molar pregnancies are typically diagnosed earlier in pregnancy, complications can arise later, including spotting, especially if there are residual trophoblastic disease issues.
  • Uterine or cervical cancer: These are rare in pregnancy but can cause spotting. Given the potential severity, they should be considered in the differential diagnosis, especially if other risk factors are present.