Differential Diagnosis for Vaginal Bleeding in Early Pregnancy

Given the symptoms and potential diagnoses, here's a structured approach to considering the possibilities:

• Single Most Likely Diagnosis:

  • Threatened Abortion: This is often the most common diagnosis in cases of vaginal bleeding in early pregnancy where the cervix is closed, and there's no passage of tissue. It's a condition where there's bleeding, but the pregnancy is still viable, and the cervix remains closed.

• Other Likely Diagnoses:

  • Incomplete Abortion: Characterized by the partial expulsion of products of conception, with the cervix open and some tissue passed. The presence of tissue and an open cervix differentiate it from a threatened abortion.
  • Missed Abortion: This occurs when the fetus has died but remains in the uterus, often with a closed cervix. It might present with a decrease in symptoms of pregnancy and could be suspected if there's no fetal heartbeat on ultrasound.

• Do Not Miss Diagnoses:

  • Ectopic Pregnancy: Although less common, an ectopic pregnancy is life-threatening and must be ruled out, especially if there's significant pain, a positive pregnancy test, and no evidence of an intrauterine pregnancy on ultrasound.
  • Molar Pregnancy: A rare condition where an abnormal fertilization event leads to an abnormal placenta and no viable fetus. It can cause significant bleeding and is associated with potential future malignancy, making early diagnosis crucial.

• Rare Diagnoses:

  • While all the above conditions can present with vaginal bleeding, other rare causes might include a heterotopic pregnancy (a simultaneous intrauterine and ectopic pregnancy, more common in assisted reproduction), placenta previa (where the placenta covers the cervix), or other less common conditions like a cornual pregnancy (a type of ectopic pregnancy in the cornu of the uterus). These are less likely but should be considered based on specific risk factors or ultrasound findings.