Age at menarche and risk of ovarian hyperstimulation syndrome in women undergoing IVF/ICSI cycles: a retrospective cohort study

Objectives We aimed to explore the association between age at menarche (AAM) and ovarian hyperstimulation syndrome (OHSS) in fresh in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles.Design A retrospective cohort study.Setting Data were collected from a large obstetrics and gynaecology hospital in Sichuan, China.Participants This study included 17 419 eligible women aged <= 40 years who underwent the first IVF/ICSI cycles from January 2015 to December 2021. Women were divided into three groups according to their AAM: <= 12 years (n=5781), 13-14 years (n=9469) and >= 15 years (n=2169).Results The means of age at recruitment and AAM were 30.4 years and 13.1 years, respectively. Restricted cubic spline models suggested that early menarche age increased the risk of OHSS. The multivariable logistic analysis showed that women with menarche age <= 12 years were more likely to suffer from OHSS (OR 1.321, 95% CI 1.113 to 1.567) compared with those aged 13-14 years among the whole cohort. This significant relationship remained in women administered with different ovarian stimulation protocols and gonadotrophin doses. When stratified by female age, this correlation was presented only in patients aged <= 30 years (OR 1.362, 95% CI 1.094 to 1.694). And the mediation analysis showed that the relationship between AAM and OHSS was totally mediated by antral follicle counts (AFC).Conclusion Menarche age earlier than 12 years may increase the OHSS risk in women aged <= 30 years through the mediation of AFC. More prospective studies are required to verify the results.