Management of Molar Pregnancy
The management of molar pregnancy requires suction dilation and curettage (D&C) under ultrasound guidance as the primary treatment, regardless of uterine size, for patients who wish to preserve fertility. 1, 2
Diagnosis
- Vaginal bleeding is the most common presenting symptom, typically occurring between 6-16 weeks of gestation 2
- Ultrasound examination is the primary imaging modality for initial diagnosis, with characteristic findings including:
- Serum hCG measurement is typically elevated beyond the expected level for gestational age 2, 3
- Blood group determination is required for potential anti-D immunization in Rh-negative women 2
- Chest X-ray is recommended if clinical suspicion of metastases exists or as baseline 2
- Thyroid function tests should be performed if hyperthyroidism is suspected 2
Treatment
- Suction D&C under ultrasound control is the safest method of evacuation to ensure adequate emptying of uterine contents and avoid uterine perforation 1, 4
- Blood should be available pre-operatively due to risk of significant hemorrhage 2
- Hysteroscopic resection is a feasible alternative procedure for management of molar pregnancy, though further studies are needed to compare this technique with D&C 5
- Re-biopsy to confirm malignant change is not advised because of the risk of triggering life-threatening hemorrhage 1
- Histological examination is essential to achieve a correct diagnosis, as ultrasound has high false positive and negative rates, especially for partial molar pregnancy 1
Post-Evacuation Assessment
- Ultrasound or hysteroscopy should be performed to ensure complete evacuation 2
- Histologic examination is the definitive method for diagnosis and classification, differentiating between complete and partial hydatidiform mole 2
- Reference pathology review in a Gestational Trophoblastic Disease center within 2 weeks is considered best practice 2
Follow-up After Treatment
- All women with a diagnosis of molar pregnancy require careful hCG monitoring to detect recurrent disease 1, 2
- Serum hCG monitoring at least once every 1-2 weeks until normalization is recommended 2, 3
- For complete hydatidiform mole, monthly hCG for up to 6 months after normalization is recommended 2, 6
- For partial hydatidiform mole, one more normal serum hCG measurement one month after initial normalization is recommended 2, 6
- Malignant change is indicated by plateaued hCG on three consecutive samples or rising hCG on two consecutive samples 1
- Hormonal contraception is indicated during postmolar follow-up to maintain the reliability of hCG as a tumor marker 6
Special Considerations
- Prophylactic chemotherapy may be useful in the management of high-risk molar pregnancy, especially when hormonal follow-up is either unavailable or unreliable 4
- Endometrial ablation is contraindicated in patients with a history of molar pregnancy due to the increased risk of undetected recurrent gestational trophoblastic disease 7
- Twin pregnancies with a coexistent normal twin and complete hydatidiform mole result in healthy babies in approximately 40% of cases, without an obvious increase in the risk of malignant change 1
- The reproductive outcomes after molar pregnancy are comparable with those of the general population, except for a higher occurrence of recurrent molar pregnancy (1.0-2.0% of subsequent pregnancies) 6
Complications and Risks
- Post-molar gestational trophoblastic neoplasia (GTN) develops in about 15% to 20% of complete moles and 1% to 5% of partial moles 1
- Patients with recurrent complete hydatidiform mole may have familial recurrent hydatidiform mole (FRHM), an autosomal recessive condition associated with mutations in NLRP7 and KHDC3L genes 1
- Women with FRHM are unlikely to achieve a normal pregnancy except through ovum donation from an unaffected individual 1
- Molar pregnancy can be associated with hyperthyroidism, early onset pre-eclampsia, or abdominal distension due to theca lutein cysts 8