Differential Diagnosis for Early Gestational Failure

Given a patient with a gestational sac and ongoing lower serum beta hCG, the following differential diagnoses can be considered:

• Single Most Likely Diagnosis
  • Miscarriage (Spontaneous Abortion): This is the most likely diagnosis given the presence of a gestational sac and declining beta hCG levels. A miscarriage is a common cause of early gestational failure, and the symptoms and lab findings align with this diagnosis.
• Other Likely Diagnoses
  • Ectopic Pregnancy: Although less likely if a gestational sac is seen in the uterus, an ectopic pregnancy cannot be entirely ruled out without further investigation, especially if the beta hCG levels are not rising appropriately.
  • Molar Pregnancy: This condition, characterized by abnormal trophoblastic proliferation, can present with a gestational sac and abnormal beta hCG levels. However, it typically presents with higher than expected beta hCG levels for the gestational age.
• Do Not Miss Diagnoses
  • Heterotopic Pregnancy: This is a rare condition where there is both an intrauterine and an ectopic pregnancy. It is crucial to consider this diagnosis, especially in patients undergoing fertility treatments, as missing an ectopic pregnancy can be life-threatening.
  • Pregnancy with a Coexisting Medical Condition: Certain medical conditions, such as thyroid dysfunction or multiple gestations, can affect beta hCG levels and the progression of pregnancy. Identifying and managing these conditions is critical for the health of both the mother and the fetus.
• Rare Diagnoses
  • Pseudocyesis (False Pregnancy): A condition where a woman believes she is pregnant along with some physical symptoms of pregnancy, but without an actual pregnancy. This could potentially present with confusing symptoms and lab results.
  • Choriocarcinoma: A rare type of cancer that occurs in the uterus, often following a molar pregnancy, miscarriage, or ectopic pregnancy. It can present with high beta hCG levels, but the clinical context would typically be different from early gestational failure.