Association between embryo morphological quality and birth weight for singletons conceived via autologous fresh embryo transfer: an analysis using Society for Assisted Reproductive Technology Clinical Outcomes Reporting System

To determine if morphologically suboptimal embryo quality is associated with adverse perinatal outcomes.A retrospective cohort.SART CORS database.Singletons conceived from autologous in vitro fertilization fresh cycles.None.Birth weight (gram), birth weight z-score, low birth weight (LBW), small for gestational age (SGA), and large for gestational age (LGA).Among 5,869 in vitro fertilization fresh cycles, 71.1% transferred morphologically good embryos, and 27.0% and 1.9% transferred fair and poor embryo(s), respectively. Compared with singletons conceived from good embryos, singletons from poor embryos had a higher birth weight (3,415.8 ± 562.0 vs. 3,202.7 ± 639.9). Proportions of LBW, SGA, and LGA were comparable across embryo quality groups. Multivariate regression analysis comparing perinatal outcomes from fair vs. good embryos showed no association for birth weight (0.69-gram difference; 95% CI, -24.30-25.68), birth weight z-score (Coefficient, 0.00; 95% CI, -0.07-0.08), LBW (adjusted odds ratio [aOR], 0.84; 95% CI, 0.63-1.11), SGA (aOR, 0.93; 95% CI, 0.78-1.11), and LGA (aOR, 1.07; 95% CI, 0.86-1.33). Stratified analysis, considering cleaved and blastocyst embryo transfers separately, confirmed these findings. Sensitivity analysis revealed increased odds of LGA (aOR, 1.53; 95% CI, 1.04-2.24) with fair-quality embryos only among single embryo transfer cycles.Once a singleton live birth from fresh embryo transfer is achieved, fair morphological embryo quality is not associated with a reduction in birth weight or increased risks of LBW, SGA, and LGA.