Background: The number of multiple pregnancies is considered to be the most important adverse effect of in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI). IVF or ICSI with transferring only one embryo, elective single embryo transfer (eSET), will reduce this incidence remarkably. Unfortunately, former research has documented that cycles with SET maintain lower pregnancy rates compared to double embryo transfer (DET). Implementation of eSET will require a carefully chosen and thoroughly defined implementation strategy focussed on the couple undergoing the subfertility treatment. This trial will investigate the (cost)effectiveness of a combined patient centred implementation strategy.

Objective: The main aim is to compare the effectiveness and costs of implementation of elective single embryo transfer (eSET) in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), between usual care and a combined patient-centred strategy.

Study design: A randomised controlled trial

Study population: Couples with a female age less than 40 years ongoing an IVF/ICSI treatment in 2 of the 13 Dutch IVF centres and their 4 satellite/transport centres.

Intervention A combined patient centred implementation strategy for eSET in IVF/ICSI. The strategy consists of counselling through an evidence based decision aid and reimbursement of a 4th cycle if couples have chosen for eSET in the first 2 cycles.

Primary study parameters/outcome of the study: the eSET occurrence rate, pregnancy outcomes and cost-effectiveness of the combined strategy.

Secondary study parameters/outcome of the study:

• patient knowledge
• patient decisional conflict
• patient satisfaction
• IVF/ICSI treatment outcome.

see above

Inclusion Criteria:

• Female age < 39 years
• In first cycle minimum of two embryos available for transfer

Exclusion Criteria:

• Medical necessity for single embryo transfer