The strategy of frozen-thawed blastocyst transfer in women over 40 years / 中国医师杂志

ABSTRACT

Objective:To explore the selection strategy of blastocyst transfer number in freeze-thaw cycle for women over 40 years old, so as to provide reference for reducing twin rate and improving perinatal clinical outcome.Methods:A retrospective analysis was made of 377 patients who underwent freeze-thaw blastocyst transplantation in the reproductive center of Guangdong Maternal and Child Health Hospital from January 2017 to December 2019. They were divided into single blastocyst and double blastocyst transplantatio groups according to the number of blastocyst transplantation. The clinical pregnancy rate, implantation rate, abortion rate, live birth rate, premature delivery rate, twin rate and singleton delivery rate were compared between the two groups.Results:⑴There was no significant difference between two groups regarding the majority of baseline characteristics, including age at retrieval, age at transfer, body mass index (BMI), antral follicle count (AFC), basal follicle stimulating hormone (FSH), anti Mullerian hormone (AMH), endometrial thickness at transfer day, number of oocytes retrieved, Gn starting dose, Gn days, Gn dosage, embryos at cleavage stage and top-quality embryos ( P>0.05). ⑵ There was no significant difference in the rate of implantation, early pregnancy loss, late pregnancy loss and live birth between two groups ( P>0.05). ⑶ The preterm birth rate was higher in the double blastocyst transplantation group compared with the single blastocyst transplantation group, albeit not reaching significant difference (31.7% vs 12.5%, P=0.083). ⑷ The clinical pregnancy rate and the twin pregnancy rate was significantly higher in the double blastocyst transplantation group compared with the single blastocyst transplantation group ( P<0.05). ⑸ The singleton birth rate was significantly lower in the double blastocyst transplantation group compared with the single blastocyst transplantation group (75.61% vs 95.83%, P<0.05). Conclusions:In women ≥40 years old, transferring a single blastocyst can result in live birth rate that is similar as transferring two blastocysts while dramatically reducing the risk of twin pregnancy rate and increasing singleton birth rate.