During IVF treatment patient preference shifts from singletons towards twins but only a few patients show an actual reversal of preference.

Background: Knowledge of patients' preferences for elective single embryo transfer (eSET) or double embryo transfer (DET) and for singletons or twins is of great importance in counselling for embryo transfer (ET) strategies. In this study, the stability of IVF patients' preferences over time for either a healthy single child or healthy twins was measured and we investigated which factors could explain preference shifts.

Methods: Infertile women (n = 177) who participated in an RCT comparing one cycle eSET with one cycle DET were included. A satisfaction questionnaire was developed to measure patient preferences and attitudes at two moments in time, i.e. at 2 weeks before ET and at 2 weeks following ET, after the results of the pregnancy test. Regression analysis examined the effect of several variables on preference shifts.

Results: Before ET, most patients expressed a preference for a singleton, whereas most patients were indifferent 2 weeks after ET, resulting in an overall preference shift towards twins (P = 0.002; n = 145). Overall, 62% of patients showed a preference shift. Preference shifts were explained by patients' global satisfaction of the information given by the fertility clinic staff received by the fertility clinic staff, and an interaction between the occurrence of pregnancy and transfer policy (eSET or DET).

Conclusions: In general, patients' preferences for a singleton or twins are not stable during IVF treatment. Possible explanations of a shift in preference are that pregnant patients attuned their preferences to what they expect their pregnancy to result in, whereas non-pregnant patients shifted towards a preference for twins in order to be able to fulfil their ultimate child wish.