Impact of chromosomal polymorphisms on pregnancy outcomes after in vitro fertilization or intracytoplasmic sperm injection: A systematic review and meta-analysis.

Objective: Chromosomal polymorphisms (CPs), subtle variations in chromosome structure, have been previously reported in individuals with infertility, particularly among men. This systematic review and meta-analysis aim to analyze associations between CPs and pregnancy outcomes, focusing on spontaneous abortion rates. Methodology: A comprehensive literature search was conducted across three databases Medline, Google Scholar and Science Direct databases from inception to December 2023 for articles reporting the impact of CPs on selected fertilization and pregnancy outcomes among men/women/couples who had sought assisted reproductive technologies [ART; either in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI)]. We applied the inverse variance method for pooled risk ratios (RR) with 95% confidence intervals (CIs). Results: From an initial 4271 articles, 16 studies met the inclusion criteria. The analysis evaluated CPs in relation to reproductive outcomes, including abortion rates (AR), fertilization rates (FR), cleavage rates (CR), clinical pregnancy rates (CPR), and good-quality embryo rates (GQER). No significant associations were observed between CPs and AR across men, women, or couples, though high heterogeneity suggested variability in study populations. CPs were associated with a modest reduction (7%) in FR (RR 0.93, 95% CI 0.88-0.97, I2 = 67.8; P-value = 0.04), and GQER (RR 0.93, 95% CI 0.89-0.96, I2 = 17.4; P-value = 0.30), and a small but statistically significant reduction CRs (RR 0.98, 95% CI 0.97-0.99, I2 = 0.0; P-value = 0.48). Conclusions: The study highlights the influence of CPs on certain fertilization and pregnancy outcomes, particularly GQER, FR and CR, while their impact on miscarriage and clinical pregnancy outcomes remains inconclusive. Further large-scale studies are necessary to investigate further associations.