Aim: This study investigated whether trophoectoderm (TE) biopsy adversely impacts serum β-human chorionic gonadotropin (hCG) level on the 15th day of embryo transfer (ET), delivery week and birthweight, between biopsied and unbiopsied embryo groups, in a cohort of women who delivered a singleton baby, following frozen–thawed ET. Methods: All women having had a live birth after blastocyst ETs following frozen ET cycles with preimplantation genetic testing (PGT) were included. A control group was selected among women who had a live birth following single frozen blastocyst transfer without PGT-A at the same period in our clinic Results: One hundred fifteen and 173 cycles with- and without-PGT, respectively, were included. Serum β-hCG level on the 15th day after ET was comparable between the groups (p =.336). Average birthweight of the babies born following biopsied embryos were significantly lower (3200 vs. 3380; p =.027). Women who received trophectoderm biopsied embryos had a significantly higher probability of having a baby weighing ≤1500 g and 1500–2500 g (p =.022) or ≤2500 g (p =.008). Proportion of preterm delivery was significantly higher in the biopsy group (p =.023). However, after adjusting for potential covariates, trophectoderm biopsy did not seem to increase the risk of preterm birth (OR 1.525; 95% CI, 0,644–3.611; p =.338) Conclusions: TE biopsy does not seem to impact serum β-hCG level on the 15th day after ET. Average birthweight is lower when a biopsied embryo was transferred. After adjusting for potential covariates, trophectoderm biopsy does not seem to increase the risk of preterm birth [ABSTRACT FROM AUTHOR]