Purpose: Hydatidiform mole (HM) is the commonest type of gestational trophoblastic disease (GTD), a human pregnancy characterized by excessive trophoblastic proliferation and abnormal embryonic development. Recurrent hydatidiform mole (RHM) is a rare genetic disorder defined by the occurrence of at least two molar pregnancies in the same patient. The frequency of RHMs is very variable between different ethnicities and countries.
Materials and Methods: An observational prospective study to investigate risk factors, reproductive history and reproductive outcome in RHM patients at GTD clinic, Mansoura university hospital.
Results: Twenty-five cases of RHM were reported. Mean age of the studied cases was 29.56 years ±4.60 SD. Nineteen cases (76%) were nulliparous. Medical history of hypertension was observed in four cases (16%). Four cases of familial RHM with a history of consanguinity between the patients' parents were reported. Recurrent complete hydatidiform moles (CHM) were reported in 13 cases (52%) while recurrent partial hydatidiform moles (PHM) were reported in 3 cases (12%). Rate of GTN progression after complete and partial moles was 28% and 4% respectively. Viable term pregnancy was achieved in five cases (20%) during follow up while 11cases (44%) resulted in molar pregnancy.
Conclusion: Recurrent molar pregnancy in Egypt appears to involve about 10% for a second or more molar pregnancies. For two consecutive episodes of molar pregnancy, subsequent molar pregnancy risk rises to 44%. Prior molar pregnancy, type of the preceding mole (CHM), nulliparity, parent consanguinity and family history of similar conditions are considered risk factors implicated in the causation of RHM.