Objective: To examine the impact of laser-assisted hatching (LAH) technique on perinatal outcomes in blastocyst culture of low-grade cleavage embryos, so as to provide insights into improving the utilization of low-grade cleavage embryos and embryo quality. Methods: A total of 369 single live births after transfer of thawed blastocysts following in vitro fertilization or intracytoplasmic sperm injection at Zhejiang Provincial People's Hospital were selected as subjects, and they were divided into 51 conventional culture blastocysts and 318 LAH blastocysts based on whether LAH was performed on day 4 of blastocyst culture. Gestational age, birth weight, birth defects and maternal perinatal information were collected, and the prevalence of premature birth, birth weight and birth defects were analyzed after propensity score matching (PSM). Results: After PSM, 98 matched cases were included in the study. There were no statistically significant differences in maternal age, body mass index, type of infertility and blastocyst age (P>0.05), indicating effective matching. The birth weight of offspring in the LAH group was lower than that in the conventional culture group [(3 261.08±432.24) g vs. (3 464.18±444.46) g; P<0.05]. Conclusion The birth weight of offspring can be reduced by using LAH during blastocyst culture of low-grade cleavage embryos.