Differences in current clinical features of diploid and triploid hydatidiform mole

Abstract

Objective: To describe and compare the current clinical features of diploid and triploid molar pregnancy and to evaluate whether the presenting clinical features can predict the ploidy of a molar pregnancy.

Design: A retrospective study of the clinical features and ploidy of hydatidiform moles.

Setting: The Departments of Clinical Genetics and Pathology, Aarhus University Hospital and 13 gynaecological wards, Jutland, Denmark.

Population: A total of 259 women with molar pregnancy diagnosed between April 1986 and June 2003.

Methods: A review of medical records of consecutively collected, clinically suspected cases of molar pregnancy was performed. The molar ploidy was determined by karyotyping, flow cytometry, and/or analysis of polymorphic DNA markers.

Main outcome measures: Maternal characteristics, presenting symptoms, initial human chorionic gonadotrophin (hCG), and molar ploidy.

Results: In a multiple logistic regression model, initial hCG of > or = 100,000 iu/l (P < 0.001), first-trimester gestational age (P < 0.001), vaginal bleeding (P < 0.001), and maternal age of > or = 40 years (P = 0.03) were independent predictors of diploid mole. Women with excessive uterine size more frequently had a diploid than a triploid mole (P < 0.001). Fifty-four percent of the women with triploid mole and 27% of the women with diploid mole were diagnosed before onset of symptoms (P < 0.001).

Conclusions: The current clinical features of diploid mole are different from those of triploid mole. The presenting clinical profile of a molar pregnancy may be used as an early predictor of the molar ploidy and thus of the prognosis.