Analyzed the dynamic measurement of the growth and development to children born of vanishing twin syndrome : A propensity matching study

Abstract Objective: The purpose of this study was to estimate the effect of vanishing twin syndrome (VTS) on the dynamic measurement of growth and development to the singletons (0-3years) born from frozen embryo transfer(FET). Methods: This study was a retrospective cohort design and was carried out at a single center from January 2017 to December 2023. The follow-up data of the children were obtained from the Jiangsu Province Maternal and Child Database. A total of 719 singleton live births were included,according to whether or not VTS occurred,they were divided into two groups resulting to the 653 children and 66 children, respectively. To optimize statistical efficiency and reduce confounding variables, singletons conceived using VTS were matched at a 4:1 ratio based on the couple's ages, BMI, occupation, women's AMH, and embryo status, ultimately 66 children in the VTS group and 264 children in the non-VTS group were included in the final analysis. Results: After the propensity matching , there was no significant difference in growth and development of children between the VTS group and non-VTS group. The number of the embryo transfer in VTS group were higher than the non-VTS group(p＜0.0001).The height and the head circumference (3 months) in VTS group were lower than the non-VTS group(p＜0.05). Conclusions: The occurrence of VTS did not detrimental affect the growth and development of offspring(0-3years) from FET. More reasonable, comprehensive and long-term follow-up results are needed for further verification. More than one embryo transfer not only increases the rate of multiple births, but also increases the occurrence of VTS in assisted reproductive technology(ART).