Molar pregnancy


  • Type of gestational trophoblastic disease
    • Neoplasm of placental hCG-producing trophoblast cells
    • Non-invasive (invasive form is choriocarcinoma, can metastasize to brain, liver, lung)
  • Non-viable fertilized egg implants in uterine wall
    • Complete: all chorionic villi are vesicular, swollen, with no embryonic development
      • 46, XX karyotype
    • Partial: some vesicular chorionic villi, +/- (nonviable) embryonic development
      • 69, XXX or 69, XXY

Clinical Features

Due primarily to elevated levels of hCG[1]

Differential Diagnosis

Nausea and vomiting in pregnancy


Molar pregnancy on ultrasound (transvaginal)
Molar pregnancy on ultrasound (transabdominal)
Hydatidiform mole on CT, sagittal view (not study of choice)
  • Serum hCG > 100,000 mIU/mL suggest excessive trophoblastic growth[2]
    • Normal hCG level does not exclude molar pregnancy
    • Partial molar pregnancies are more likely to produce lower hCG levels
  • Evaluate for other causes of or electrolyte derangements due to vomiting
  • Other serum lab workup
    • CBC
    • BUN/Cr/Electrolytes
    • LFTs
    • Thyroid function tests
  • Consider CXR or CT chest if there is suspicion of pulmonary metastases[3]
  • Pelvic ultrasound
    • Complete mole - enlarged uterus with interspersed lucent and brighter areas ("snowstorm" appearance)
    • Before 12 weeks, may show a fine vascular or honeycomb appearance
    • Ovaries may contain multiple large theca-lutein cysts due to excessive beta-hCG
    • Partial mole - more difficult to diagnose, with the fetus possibly being viable
      • Scattered cystic spaces within placenta
      • Ovarian cystic changes less pronounced than in complete mole


  • Ob/gyn consult
    • Suction curettage as inpatient (due to risk of bleeding)
  • Resuscitate if severe bleeding
  • Treat preeclampsia
  • Symptomatic treatment of nausea/vomiting


  • Admit

See Also

External Links


  1. Cavaliere A et al. Management of molar pregnancy. J Prenat Med. 2009 Jan-Mar; 3(1): 15–17.
  2. Diagnosis and treatment of gestational trophoblastic disease: ACOG Practice Bulletin No. 53. Soper JT, Mutch DG, Schink JC, American College of Obstetricians and Gynecologists. Gynecol Oncol. 2004 Jun; 93(3):575-85.
  3. Initial management of hydatidiform mole. Schlaerth JB, Morrow CP, Montz FJ, d'Ablaing G. Am J Obstet Gynecol. 1988 Jun; 158(6 Pt 1):1299-306.