Outcome of subsequent pregnancies in familial molar pregnancy.

Familial recurrent molar pregnancy is an exceedingly rare condition, in which complete hydatidiform moles are mostly diploid but biparental in origin and the outcome of subsequent pregnancies is likely to be a hydatidiform mole or other type of reproductive loss. We previously reported a case of familial molar pregnancy (family K) comprising five affected members (four sisters and one of their cousins) each with at least one hydatidiform mole (HM). In addition to the molar pregnancies, these patients have a total of three miscarriages and 8 normal pregnancies leading to healthy children; but the youngest member of this family has given birth to a boy with Down syndrome. Our second family (case S) includes two sisters with diploid biparental complete moles. They have a total of six molar pregnancies with no living child. Recently the younger sister had a partial molar pregnancy with apparently normal XX fetus accompanying diffuse molar changes of the placenta that led to preeclampsia and preterm delivery. Overall, these families have had 26 pregnancies including 12 molar pregnancies (complete or partial) and three abortions. We concluded that these families are predisposed to various genetic mutations, chromosomal abnormalities and clinical manifestations, which affect their offspring. Further studies of patients are needed to determine any relationship between a history of familial molar pregnancy and trisomy or other chromosomal abnormalities in offspring and genetic mutations in the products of conception to complete the puzzle and manage familial molar pregnancy.