Cumulative live birth rates following blastocyst- versus cleavage-stage embryo transfer in the first complete cycle of IVF: a population-based retrospective cohort study

AbstractSTUDY QUESTIONIs there a difference in the odds of a live birth following blastocyst- versus cleavage-stage embryo transfer in the first complete cycle of IVF?SUMMARY ANSWERAfter adjusting for indication bias, there was not enough evidence to suggest a difference in the odds of live birth following blastocyst- versus cleavage-stage embryo transfer in the first complete cycle of IVF.WHAT IS KNOWN ALREADYReplacement of blastocyst-stage embryos has become the dominant practice in IVF but there is uncertainty about whether this technique offers an improved chance of cumulative live birth over all fresh and frozen-thawed embryo transfer attempts associated with a single oocyte retrieval.STUDY DESIGN, SIZE, DURATIONNational population-based retrospective cohort study of 100  610 couples who began their first IVF/ICSI treatment at a licenced UK clinic between 1 January 1999 and 30 July 2010.PARTICIPANTS/MATERIALS, SETTING, METHODSData from the Human Fertilisation and Embryology Authority (HFEA) register on IVF/ICSI treatments using autologous gametes between 1999 and 2010 were analysed. The primary outcome was the live birth rate over the first complete cycle of IVF. Cumulative live birth rates (CLBR) were compared for couples who underwent blastocyst and cleavage transfer, and the adjusted odds of live birth over the first complete cycle were estimated for each group using binary logistic regression. This analysis was repeated within groups of female age, oocytes collecte...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research