Abstract
AbstractBackgroundTo study the relationship between blastocyst morphology and the sex ratio of singleton births in single blastocyst transfer cylces.MethodsThis retrospective cohort study included women who underwentin vitrofertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) from January 2017 to December 2019 and obtained a single live baby following a single blastocyst transfer. The sex ratio which influenced by many possible factors were studied. Age-stratified analysis was performed for the maternal and paternal groups younger and older than 35 years. The 3108 cycles included here were grouped by sex at birth (male: 1777 cycles and female: 1331 cycles). Blastocysts were conceived via 2834 IVF and 274 ICSI treatments, and were used for 1054 fresh ET cycles and 2054 frozen-thawed embryo transfer (FET) cycles.ResultsSex ratio among singleton of poor blastocyst decreased significantly compared to those of good blastocyst (51.5% vs 60%,P<0.001). The results of multivariate logistic analysis showed that high-quality blastocysts had a 151% higher probability of being male singleton than poor-quality blastocysts (P<0.001). Further stratified analysis shows that in both group younger than 35 the sex ratio increased significantly in grades A and/or B trophectoderm (P<0.001) and good-quality blastocysts (P<0.001). While grade A inner cell mass (ICM) degree was significantly associated with a lower sex ratio than grade B (P<0.05).ConclusionsA single high-quality blastocyst transfer was significantly associated with a higher neonatal sex ratio. Grade A trophectoderm and grade B ICM contributed to improving the implantation potential of male blastocysts, especially in infertile men or women ≤35 years old.
Publisher
Cold Spring Harbor Laboratory