Shortened ovarian stimulation duration may not affect oocyte developmental competence: a retrospective study

Abstract

Abstract Background: In recent years, an increasing number of scholars have begun to pay attention to the effect of gonadotropin (Gn) on the quality of oocytes and embryos. Some studies have focused on the relationship between Gn time and in vitro fertilization (IVF) outcomes. The aim of this study was to evaluate the effect of shortened ovarian stimulation duration on oocyte developmental competence during an IVF cycle.Methods: A total of 1049 women undergoing first IVF cycles between January 2019 and December 2021 were included in this retrospective cohort study. The populations were stratified according to ovarian reserve. Polycystic ovary syndrome (PCOS) diagnosed by the Rotterdam criteria and diminished ovarian reserve (DOR), defined by the Bologna criteria. Criteria for normal ovarian reserve (NOR) are AMH levels > 1.4 ng/ml and AFC 7~20. The women were further grouped according to the duration of ovarian stimulation. A total of 139 (26.4%) patients were in the NOR≤8 days group, 387 (73.6%) were in the NOR>8 days group, 82 (27.6%) were in the PCOS≤8 days group, 215 (72.4%) were in the PCOS>8 days group, 54 (23.9%) were in the DOR≤7 days group, and 172 (76.1%) were in the DOR>7 days group. Oocyte development-related factors including oocyte retrieval rate, oocyte maturation rate, normal fertilization rate and normal cleavage rate were analysed. A generalized linear model was used to explore the association between ovarian stimulation duration and oocyte developmental competence.Results: The oocyte retrieval rate, oocyte maturation rate, normal fertilization rate and normal cleavage rate were not affected by shortened ovarian stimulation duration in any of the ovarian reserve populations. Although there were differences in baseline characteristics and ovarian stimulation-related factors among the groups, the results remained robust after we adjusted for these potential confounding factors using generalized linear model analysis.Conclusions: We did not find that a shortened duration of ovarian stimulation impaired oocyte developmental competence in any population. Shortened stimulation duration is not predictive of suboptimal results.