Competence of mature oocytes from small follicles in natural and mild stimulation in vitro fertilization

Abstract

OBJECTIVE: To evaluate the incidence of ovarian hyperstimulation syndrome (OHSS) in potential hyper ovarian responders in corifollitropin alfa without routine GnRH antagonist protocol.DESIGN: Retrospective cohort study. MATERIALS AND METHODS: Two hundred fifty donors aged 20 -34 years with anti-M€ ullerian hormone (AMH) S2.5 ng/mL were included. According to the number of retrieved oocyte, all donors were divided into two subgroups: normal (retrieved 8-20 oocytes, n¼98) and hyper (retrieved >20 oocytes, n¼152) responders. The hormone levels were monitored for determining whether other additional injections (r-LH or/and r-FSH) were necessary after one corifollitropin alfa shot. Oocyte maturation was achieved by GnRH agonist administration and the oocyte pick-up (OPU) was performed at 36 hours after triggering. The diagnosis of OHSS was based on both clinical symptoms and laboratory results including four key indicators: WBC (Cumm), PLT (10 3 /Cumm), Hb (gm/dL) and Hct (%). The following clinical outcomes from recipients were also analyzed.RESULTS: In hyper responders, significantly higher levels of body weight (52.2 kg vs. 54.0 kg), AMH (6.1 ng/ mL vs. 9.9 ng/ mL), AFC (13.2 vs. 15.4), basal LH (4.0 mIU/ mL vs. 5.4 mIU/ mL), peak E2 (2979 pg/mL vs. 5259 pg/ mL) and retrieved oocytes (15.5 vs. 30.4) were observed. The two groups were comparable in age (24.7 vs. 24.5), basal E2 (38.6 pg/mL vs. 42.4 pg/ mL), peak LH (3.8 mIU/mL vs. 3.5 mIU/ mL)maturation rate (MR , 75.9 % vs. 74.5 %) and total supplemented dosage of r-FSH (496.1 IU vs. 447.2 IU) and r-LH (241.1 IU vs. 249.2 IU). For evaluation of OHSS incidence, the pre-and post-OPU laboratory results including WBC, PLT, Hb and Hct, were monitored, and no clinical significance was found. Therefore, the degrees of OHSS were mainly classified by the clinical symptoms. There were no significant difference in the incidences of mild or moderate OHSS between normal and hyper responders (mild: 6.1% vs. 5.9%, p¼0.95 ; moderate: 5.1% vs. 9.2%, p¼0.21 ). Under this stimulation protocol, most of cases occurred OHSS were mild or moderate in both groups. In addition, the clinical outcomes did not differ between normal and hyper responders.CONCLUSIONS: Accordingly, the most concern of corifollitropin alfa administration is the possibility of relatively higher incidence of OHSS in hyper responders. In this study, the results revealed that the incidence of OHSS is no significantly different between normal and hyper responders even without GnRH antagonist administration. Therefore, with well-monitoring, this patient-friendly protocol, less injection, is also suitable for the potential hyper responders.