How Could One Sperm and One Oocyte Proceed To Molar Pregnancy? Prevalence of Molar Pregnancy during ICSI Procedure in Over 25,000 Fresh Embryo Transfers: A Retrospective Cross-Sectional Study

Gestational trophoblastic disease (GTD) is a heterogeneous group of diseases characterized by excessive proliferating trophoblastic tissue. The prevalence of GTD has a varied geographical distribution. However, its frequency following intracytoplasmic sperm injection (ICSI) cycles has not yet been reported. This study aimed to estimate GTD frequency and prevalence after ICSI cycles. This retrospective cross-sectional study included all patients diagnosed with GTD subsequent to ICSI and segmental embryo transfer procedure during 2011-2019 at Royan Institute. GTD diagnosis was established for patients who met all three criteria: beta-human chorionic gonadotropin (β-hCG) levels greater than 100,000 mIU/mL, vesicular ultrasonographic pattern, and presence of pathologic features of hydatidiform mole. Although we assessed the GTD frequency in all ICSI cycles, GTD cases were only observed following fresh embryo transfer ICSI procedures. We evaluated 25,667 fresh embryo transfer ICSI procedures out of 41,540 ICSI cycles. This study identified a total of 10 GTDs confirmed by all criteria which were mentioned previously. Of these 10 GTDs, nine cases had hydatidiform mole, and one had gestational trophoblastic neoplasia. The frequency of GTD was calculated 10 cases in 41,540 (0.240 per 1000) ICSI procedures and 10 in 25,667 (0.389 per 1000) fresh embryo transfers following ICSI cycles. Also, we detected 10 GTD cases in 8,196 (1.220 per 1000) clinical pregnancies. We discuss that the possibility of GTD after ICSI procedure is not as low as expected. Thus, the previous theses are insufficient to explain all aspects of molar pregnancy, and more research is required.