Evaluating the Impact of Female Factors on Specific Stages of Early Embryo Development: A Retrospective Analysis of 1372 IVF Cycles

Huan Jiang,1 Xiaolu Xia,1 Biyun Zhang,2 Haiyan Pan,3 Ying Luo,4 Shihao Qu,5 Jianying Xu4 1Department of Reproductive Endocrinology, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City (Affiliated Shenzhen Women and Children’s Hospital (Longgang) of Shantou University Medical College), Shenzhen, People’s Republic of China; 2School of Public Health, Guangdong Medical University, Dongguan, People’s Republic of China; 3Reproductive Immunology Department, Guangdong Provincial Reproductive Science Institute (Guangdong Provincial Fertility Hospital), NHC Key Laboratory of Male Reproduction and Genetics, Guangzhou, People’s Republic of China; 4Reproductive Medicine Center, Zhuhai Maternal and Child Health Care Hospital, Zhuhai, People’s Republic of China; 5Male Reproductive Health Department, Zhuhai Maternal and Child Health Care Hospital, Zhuhai, People’s Republic of ChinaCorrespondence: Huan Jiang, Department of Reproductive Endocrinology, Longgang District Maternity & Child Healthcare Hospital of Shenzhen City (Affiliated Shenzhen Women and Children’s Hospital (Longgang) of Shantou University Medical College), 6# Ailong Road, Longgang Central District, Shenzhen City, Guangdong, 518172, People’s Republic of China, Email [email protected] Jianying Xu, Reproductive Medicine Center, Zhuhai Maternal and Child Health Care Hospital, 543 Ningxi Road, Zhuhai City, Guangdong, 519000, People’s Republic of China, Email [email protected]: To ascertain whether female factors uniformly impact the entire spectrum of early embryo development during in vitro fertilization (IVF) treatments or if their influence is confined to specific stages.Methods: A retrospective observational study. Univariate and multivariate logistic regression analyses were performed to identify the influence of female factors on different stages of embryo development.Results: Significant differences in female age, AMH, AFC, and gonadotropin (Gn) dose were observed across the five groups (p< 0.001). When comparing the lowest (Group A) and highest (Group E) performance groups, female age (OR=1.18), AMH (OR=0.40), AFC (OR=0.86), and initial Gn dose (OR=0.99) were independent predictors of early embryo development (all p< 0.05). In contrast, when comparing intermediate (Group D) and high (Group E) performers, factors independently associated with high-quality day-5 blastocyst formation included female age (OR=1.08), AMH (OR=0.89), AFC (OR=0.91), and LH/FSH ratio (OR=1.37) (all p< 0.05).Conclusion: Female factors exert stage-specific effects on early embryo development in IVF, supporting the need for individualized clinical strategies. Notably, an optimal LH/FSH ratio was associated with improved blastocyst quality, although prospective studies are warranted to validate this threshold and its clinical applicability.Keywords: in vitro fertilization, early embryo development, LH/FSH ratio, cluster analysis, blastocyst quality