Perinatal outcomes of singletons following vitrification versus slow-freezing of embryos: a multicenter cohort study using propensity score analysis

AbstractSTUDY QUESTIONIs embryo vitrification associated with a higher risk of adverse perinatal outcomes than slow-freezing?SUMMARY ANSWEREmbryo vitrification was not associated with increased risks of adverse perinatal outcomes of pre-term birth (PTB), low birthweight (LBW), small for gestational age (SGA), large for gestational age (LGA) and macrosomia, as compared to slow-freezing.WHAT IS KNOWN ALREADYVitrification is becoming a widely adopted technology for embryo cryopreservation with higher embryo survival rate and live birth rate than the slow-freezing technique. However, limited data are currently available on risks of adverse perinatal outcomes following vitrification as compared to that of slow-freezing. The impact of vitrification on perinatal outcomes remains further to be elucidated.STUDY DESIGN, SIZE, DURATIONSix large reproductive medical centers in Guangdong province, Southeast of China, took part in this multicenter retrospective cohort study. Cohorts of 3199 live born singletons after Day 3 frozen-thawed embryo transfer (FET) cycles with either vitrification or slow-freezing between January 2011 and December 2015 were included in the study. Each patient only contributed one cycle per cohort and vanishing twins were excluded. Propensity score (PS) matching was used to control for potential confounding factors.PARTICIPANTS/MATERIALS, SETTING, METHODSAll live-born singletons following either a vitrified or a slow-frozen cleavage FET cycle during the period fro...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research