Differential Diagnosis
- Single most likely diagnosis
- Monochorionic-diamniotic twin pregnancy: This diagnosis is the most likely due to the presence of two 8-week intrauterine gestations with a single placenta and no dividing intertwin membrane on ultrasound. The patient's history of ovulation induction also increases the risk of multiple gestations.
- Other Likely diagnoses
- Threatened abortion: The patient presents with light vaginal spotting and mild abdominal cramping, which are common symptoms of a threatened abortion. However, the presence of two intrauterine gestations with normal heartbeats makes this diagnosis less likely.
- Miscarriage: Although the patient has a history of infertility and prior ectopic pregnancy, the ultrasound findings of two viable gestations make miscarriage less likely.
- Do Not Miss
- Ectopic pregnancy: Although the ultrasound shows two intrauterine gestations, the patient's history of prior ectopic pregnancy and current presentation with vaginal spotting and abdominal cramping make it essential to rule out another ectopic pregnancy, especially if there are any concerns about the ultrasound findings or if the patient's symptoms worsen.
- Placenta previa: Although not directly suggested by the ultrasound findings, placenta previa can cause vaginal bleeding in pregnancy and should be considered, especially if the patient's bleeding worsens or if there are concerns about the placental location.
- Rare diagnoses
- Molar pregnancy: Although rare, a molar pregnancy can cause vaginal bleeding and should be considered if the ultrasound findings are atypical or if the patient's symptoms worsen.
- Heterotopic pregnancy: This is a rare condition where there is both an intrauterine and an ectopic pregnancy. Although the ultrasound shows two intrauterine gestations, the patient's history of prior ectopic pregnancy and current presentation make it essential to consider this rare diagnosis, especially if there are any concerns about the ultrasound findings or if the patient's symptoms worsen.