This study analyzed the effects of the day of trophectoderm (TE) biopsy and blastocyst grade on clinical and neonatal outcomes. The results showed that the implantation and live birth rates of day 5 (D5) TE biopsy were significantly higher compared with those of D6 TE biopsy. The miscarriage rate of the former was lower than that of the latter, but there was no statistically significant difference. Higher quality blastocysts can achieve better implantation and live birth rates. Among good quality blastocysts, the implantation and live birth rates of D5 and D6 TE biopsy were not significantly different. Among fair quality and poor quality blastocysts, the implantation and live birth rates of D5 TE biopsy were significantly higher compared with those of D6 TE biopsy. Neither blastocyst grade nor the day of TE biopsy significantly affected the miscarriage rate. Neonatal outcomes, including newborn sex, gestational age, preterm birth, birth weight and low birth weight in the D5 and D6 TE biopsies were not significantly different. Both blastocyst grade and the day of TE biopsy must be considered at the same time when performing preimplantation genetic testing-frozen embryo transfer.
Keywords: Clinical outcomes; FET; Neonatal outcomes; PGT; Trophectoderm biopsy.