Characteristics of women with recurrent molar pregnancies

Objectives. The aim of this study was to examine the incidence and characte ristics of women who develop a second molar pregnancy after a previous epis ode of gestational trophoblastic disease. Methods. A retrospective analysis was carried out on completed registration forms from referring hospitals in the North of England to the Sheffield Tr ophoblastic Screening Service over a 13-year period. Ail cases of second mo lar pregnancy were identified. Details of histology, blood group, ethnic or igin, age, and subsequent pregnancies were examined. Results. Between 1 January 1985 and 31 December 1997, 5030 patients were re gistered for follow-up and 275 (5.5%) required treatment for persistent dis ease. Thirty-five women had a subsequent molar pregnancy, a total of 0.70% of all registrations. There was no significant difference in age at first r egistration between those who were registered for one molar event and those who developed a subsequent molar pregnancy. The risk of a second molar eve nt was highest in the second year after the initial diagnosis and reduced t hereafter. There was a trend toward an increased risk of second molar pregn ancy in Indian/Pakistani women when compared to Caucasian women (relative r isk 2.4) but this was not significant at conventional levels. There was a s ignificantly increased incidence of blood group B in patients that develope d a molar pregnancy when compared to the normal population (P < 0.05), but there was no difference in distribution of blood group between those regist ered for their first molar event and those with two or more events. Patient s who presented with a partial mole tended to have a partial mole as the se cond event but patients who presented with a complete mole were at risk of a subsequent complete mole, partial mole, or choriocarcinoma. Six percent o f patients required chemotherapy for the second molar event, indicating no increase in aggressiveness in second moles. Two patients had three molar ev ents. Conclusion. In the United Kingdom the risk of second molar pregnancy is les s than 1%. There is an increased risk of molar pregnancy in women with bloo d group B and a trend toward an increased risk of second molar pregnancy in Indian/Pakistani women. Only 6%\ of patients required chemotherapy for the second mole; a second molar pregnancy is not an indication for chemotherap y. (C) 2000 Academic Press.