Determinants of the choice for single or double embryo transfer in twin prone couples.

BACKGROUND: Some 84% of all European in vitro fertilisation (IVF) and intracytoplasmatic sperm injection (ICSI) cycles is performed with the transfer of more than 1 embryo, with 22% resulting in twin pregnancies. At many centres, the choice for one or more embryos is made through a shared decision-making process. To reduce the twin rate in a twin prone population by increasing the use of elective single embryo transfer (eSET), it is important to identify which objective patient factors are related to the choice for double embryo transfer (DET) and eSET. Therefore, the aim of this study was to identify determinants related to the choice for the transfer of eSET or DET in a twin prone population. METHODS: A retrospective study was performed on 477 twin prone couples at 2 Dutch IVF centres. We collected data on possible objective patient determinants, and a multivariate logistic regression analysis was performed to determine the impact of these determinants on the decision for DET. RESULTS: Of the twin prone couples, 61% opted for DET in their first IVF/ICSI cycle. Within the multivariate analysis, two objective patient determinants acted as a risk factor for the choice of DET - a lower number of available embryos (p=0.03) and a previous ongoing pregnancy after IVF/ICSI (p=0.04). The explained variance of the determinants was 3%. CONCLUSIONS: In twin prone couples, 61% still opted for DET in their first IVF/ICSI cycle. We identified 2 objective patient determinants for DET, but with an explained variance of only 3%. Therefore, further research is necessary to identify barriers and facilitators for eSET at both the level of the couples and clinicians