Evaluation of success rate of second curettage of hydaditiform mole on prevention of development of the persistent trophoblastic disease

Suction curettage is the preferred method for evacuation of hydatidifrom mole. The possibility of the persistent of the disease after first curettage is about 20%. Residual tissue is one of the causes of continue secretion of hCG and misappropriate decrease of hCG. The purpose of this study was to evaluate the efficacy of second curettage to remove any residual tissue in the uterine cavity in decreasing the possibility of development of persistent trophoblastic disease. Subjects and In this case-control study we followed 160 patients, in two equal case and control groups, with hydatidiform mole after routine evaluation. We performed an ultra-sonograpahy a few hours after first suction curettage for case–group and a second curettage on the next day when endometrial thickness above 10mm or any residual tissue in uterine cavity was observed. While in control group routine suction curettage was performed. Both groups were followed-up routinely until negative or persistent βhCG weekly. There was no significant differences between the groups with respect of age, parity, uterine size and other risk factors. Sonography results in case group was abnormal in 34.8% of patients. Twenty five percent of case group developed persistent trophoblastic disease, in whom 8% showed normal, and 17 % showed abnormal sonography. While 34 % of control cases developed persistent trophoblastic disease, in whom showed normal and abnormal sonography respectively. This study showed that in the first instance, the prognosis is much better of no residual tissue is left after the first evacuation. Secondly if a residual tissue is present, a second curettage is effective in reducing the incidence of development of persistent trophoblastic disease more than suction method. Finaly the stage of the disease is a good prognostic factor in overall response to treatment.