Molar Pregnancy (Hydatidiform Mole)

Definition

Molar pregnancy is a gestational trophoblastic disease where tissue that normally develops into a fetus grows abnormally, forming a mass of cystic vesicles in the uterus. It is potentially malignant and requires prompt diagnosis and treatment.

• Two main types:

  1. Complete mole – No viable fetus; entire placental tissue abnormal

  2. Partial mole – Abnormal fetus present, often non-viable

Epidemiology / Risk Factors

• Most common in women under 20 or over 35 years of age

• Previous history of molar pregnancy

• Nutritional deficiencies (e.g., low carotene or protein)

• History of miscarriage or infertility treatment

Clinical Presentation

Signs and Symptoms

• Vaginal bleeding (often brownish, watery, or grape-like tissue)

• Uterus larger than gestational age, with no palpable fetal parts

• Severe nausea and vomiting (hyperemesis gravidarum)

• Excessive vaginal discharge of trophoblastic tissue

• Rapid uterine growth

• Signs of anemia due to heavy bleeding

• Occasionally, hyperthyroidism (due to high hCG levels)

Investigations

1. Laboratory Tests

   • Serum β-hCG: markedly elevated for gestational age

   • CBC: assess for anemia

   • Liver and renal function tests if persistent vomiting or systemic effects

2. Imaging

   • Ultrasound: classic “snowstorm” or “cluster of grapes” appearance

   • Absence of fetal cardiac activity in complete mole

   • Assess for theca lutein cysts in ovaries

3. Histopathology

   • Confirm diagnosis post-evacuation (MVA or D&E)

   • Helps distinguish between complete and partial mole

Treatment

Immediate Measures

• Stabilize patient if bleeding or anemia is present

• Correct fluid and electrolyte imbalances

Uterine Evacuation

• Preferred method: Suction curettage (Manual Vacuum Aspiration – MVA or Electric Vacuum Aspiration)

• Cervical preparation may be required for large uterine size

• Avoid sharp curettage to reduce risk of perforation

Post-Evacuation Care

• Monitor β-hCG levels weekly until undetectable, then monthly for 6 months to 1 year

• Contraception: Avoid pregnancy for 6–12 months to allow monitoring

• Follow-up imaging if β-hCG plateau or rises (rule out persistent trophoblastic disease)

Complications to Monitor

• Persistent gestational trophoblastic neoplasia

• Excessive hemorrhage

• Hyperthyroidism or pre-eclampsia-like symptoms in early pregnancy

• Rarely, pulmonary embolism

Pharmacologic Support

• Blood transfusion if severe anemia

• Anti-emetics for hyperemesis

• Methotrexate or chemotherapy if persistent disease

Patient Education

• Importance of regular follow-up and β-hCG monitoring

• Signs of complications: heavy bleeding, abdominal pain, fever

• Avoid conception during monitoring period

• Psychosocial support, as this may be emotionally distressing

Summary / Key Points

1. Molar pregnancy is a gestational trophoblastic disorder requiring prompt diagnosis and evacuation

2. Classic signs: vaginal bleeding, large uterus, absent fetal parts, hyperemesis

3. Diagnosis: Ultrasound + β-hCG

4. Treatment: Suction curettage with follow-up β-hCG monitoring

5. Complications: persistent trophoblastic disease, anemia, hyperthyroidism

6. Contraception and psychosocial support are essential for post-treatment care