Obstetrical and neonatal outcome after controlled ovarian stimulation for IVF using the GnRH antagonist ganirelix

BACKGROUND: To establish long-term safety, follow-up data on pregnancy, birth and neonatal outcome were collected during clinical development trials with ganirelix (Orgalutran) in women undergoing controlled ovarian stimulation for conventional IVF or ICSI. METHODS: Results of an analysis of the pooled data of all follow-up data of the phase 2 and 3 programme for the development of ganirelix are presented. Obstetrical data on 340 ongoing pregnancies (greater than or equal to16 gestational weeks) after ganirelix treatment and 134 pregnancies after GnRH agonist treatment in a long protocol are shown. Furthermore, the neonatal outcome of 432 children [258 (75.9%) singletons, 72 (21.2%) twins and 10 (2.9%) triplets] born in the ganirelix group is presented and compared with 184 children [91 (67.9%) singletons, 36 (26.9%) twins and seven (5.2%) triplets] in the agonist group. RESULTS: There were no differences between the two groups in pregnancy loss after 16 weeks gestation. Incidence and nature of complications during pregnancy and delivery did not differ between the two groups. The overall mean gestational age was similar to38.0 weeks, ranging from an average of 39 weeks for singletons to 34 weeks for triplets. No major differences were observed in neonatal characteristics of infants in the ganirelix and agonist groups, who had an overall mean birth weight of on average 3200 g for singletons, 2300 g for twins and 1800-1900 g for triplets. Congenital malformations were observed in 32 of 424 (7.5%) fetuses greater than or equal to26 gestational weeks in the ganirelix group and in 10 of 181 (5.5%) in the agonist group. When applying a broad definition of major malformation (a major congenital malformation is a condition that causes functional impairment or requires surgical intervention) the rates were 4.5 versus 3.3 (odds ratio 1.37, 95% confidence interval 0.54-3.48) for the ganirelix and agonist group respectively. CONCLUSIONS: Reviewing the presented data and the literature on obstetric and neonatal outcome after conventional IVF or ICSI, we conclude that a controlled ovarian stimulation protocol including the novel GnRH antagonist ganirelix has been shown to be safe for pregnant women and their newborn babies.