Are fertility drugs a risk factor for persistent trophoblastic tumour?

BACKGROUND The introduction of ovulation-inducing drugs has raised concern that women exposed to these therapies may be at increased risk of cancer. We assessed the potential association between exposure to fertility drugs and the risk of developing persistent trophoblastic tumour (PTT). METHODS We conducted a systematic review of the English and non-English language literature using the National Library of Medicine's Medline to identify all observations of patients with hydatidiform mole (HM) after treatment with ovulation-inducers. RESULTS Fifty-two cases were considered including 26 singleton molar pregnancies and 26 multiple molar pregnancies consisting of an HM and one or more co-existent fetus(es) (HM-and-CF). PTT occurred in 15% of patients with singleton HM and in 42% of patients with HM-and-CF, 15% of whom had a metastatic disease. Of those patients with HM-and-CF, 16 patients delivered at <24 weeks gestation, mostly because of vaginal haemorrhage. Ten patients delivered at > or = 24 weeks of gestation, six of whom (25%) had a normal live child. These results are similar to spontaneously conceived pregnancies. CONCLUSIONS Although women having an HM after therapy with ovulation-inducing drugs seem to have no added risk of PTT, multiple pregnancies are more likely to occur, and the overall risk may be increased.