Triploidy

Incidence

 * 1-3% of recognized pregnancies

Molecular Etiology

 * Diandry: fertilization with 2 sperm or diploid sperm
 * Digyny: complete nondisjunction or fertilization of primary oocyte

Diandric Features

 * partial hydatidiform mole
 * malformed fetus
 * microcephaly


 * Grape-like villi in placenta
 * choriocarcinoma risk

Digynic Features

 * Severe IUGR
 * macrocephaly
 * Abnormally small, non-molar placenta

Prognosis

 * Rare survival to term; incompatible with life

Recurrence

 * General Population