Heterogeneity in the origin of recurrent complete hydatidiform moles: not all women with multiple molar pregnancies have biparental moles

Hydatidiform moles of two women, each with three molar pregnancies, were examined in order to study their origin. Multiple recurrences have previously been associated with women who have biparental complete hydatidiform moles (CHM). However, all the moles examined in this study were androgenetic CHM (AnCHM), indicating that recurrent (>2) moles, particularly in the absence of a positive family history, may be androgenetic rather than biparental. These data suggest that some women have a specific liability for having AnCHM. Making the distinction between a biparental or an androgenetic origin of recurrent moles is of relevance for counselling and when considering therapeutic options. Therefore, we propose that all recurrent moles should be investigated using molecular techniques.