Elective single embryo transfer

Abstract

The aim of the study was to evaluate if the elective single embryo transfer (eSET) strategy couldmaintain delivery rates, with at least one live born child, and at the same time decrease the rate ofmultiple births. A cost-effectiveness analysis was also performed between the elective single embryotransfer (SET) (1+1) and double embryo transfer (DET) (2+0) strategies. Another aim was toinvestigate whether it is possible, in a large randomized trial, to identify specific maternal and/orembryo variables that could independently predict ongoing implantation in IVF/ICSI.The study was a prospective randomized multicentre trial performed at five Swedish, four Danish andtwo Norwegian clinics. Patients under 36 years of age undergoing their first or second IVF cycle,resulting in at least two good-quality embryos, were randomized into two groups; one group received afresh eSET and if a live birth did not follow, a frozen SET and the other group received a DET on oneoccasion. Self-reporting questionnaires and medical records were collected to assess the obstetric andpaediatric outcomes and the costs. Two questionnaires were used to assess the quality of life of themothers. In the paper on predictors of ongoing implantation (n=521), an analysis was performed ofcycles with 0% or 100% ongoing implantation and with embryos transferred on day two, regardingmaternal and embryo variables.In the SET group a cumulative live birth rate of 128/330 (38.8%) was observed as compared with theDET group 142/331 (42.9%) (Difference 4.1%; 95% CI 3.4-11.6).The rates of multiple births in thetwo groups were 1/330 (0.8%) in SET and 49/331 (34.5%) in DET (p<0.0001). The complicationsduring pregnancy and delivery were significantly lower in the SET group, as was the rate of Caesareansections. The children in the SET group had statistically higher mean gestational ages, lower rates ofpremature birth (<37 weeks), higher mean birth weights and lower rates of low birth weight (<2500 g)as compared with those in the DET group. Perinatal morbidity was markedly higher in the DET group,and the children in the DET group had significantly more days of treatment in a neonatal ward. Theincremental cost-effectiveness ratio (ICER) was SEK 675,053 per extra delivery (n=14) in the DETgroup. Mean total cost for maternal and paediatric health care was SEK 87,434 in the SET group andSEK 115,768 in the DET group. When including the costs for loss of productivity the costs were SEK102,492 and SEK 137,935, respectively. In the paper concerning predictors of ongoing implantation,in the univariate analysis, first IVF cycle, conventional IVF as fertilization method and four-cellembryos showed a statistically higher ongoing implantation rate than did second IVF cycle, ICSI andnon-four cell embryos. In the multivariate analysis the same variables and also ovarian sensitivity,expressed as number of IU of FSH per oocyte retrieved, correlated independently to ongoingimplantation.In conclusion, the SET group achieved a rate of live birth not substantially lower than was achievablewith DET and with a lower rate of maternal and paediatric complications, especially premature births.The single embryo transfer strategy resulted in better cost-effectiveness than DET and can berecommended for good prognosis women in order to decrease the twin rate.