Early pregnancy loss rates were different among singleton gestations conceived by ICSI using GnRH agonist and antagonist.

This study compared early pregnancy losses (termination of pregnancy before 12 weeks of gestation, EPL) among conceptions achieved by ICSI according to the type of GnRH analogue for ovarian stimulation. Only singleton gestations (2,184) and fresh embryo transfers were included. GnRH agonist was used in 848 gestations out of 2,184 and GnRH antagonist was used in the remaining 1,336 gestations. EPL was found to be significantly higher in GnRH antagonist gestations compared to GnRH agonist (27.2% vs 18.9%). This significant difference persisted when gestations were segregated according to maternal age, especially among women younger than 35 years old. Therefore our results suggest that gestations conceived by ovarian stimulation including GnRH antagonists may have higher probability of having EPL.