Study question: What is the effect of a legal limitation of the number of embryos that can be transferred in an assisted reproductive technology (ART) cycle on the multiple delivery rate?
Summary answer: The Belgian national register shows that the introduction of reimbursement of ART laboratory costs in July 2003, and the imposition of a legal limitation of the number of embryos transferred in the same year, were associated with a >50% reduction of the multiple pregnancy rate from 27 to 11% between 2003 and the last assessment in 2010, without any reduction of the pregnancy rate per cycle.
What is known already: Individual Belgian IVF centres have published their results since the implementation of the law, and these show a decrease in the multiple pregnancy rate on a centre by centre basis. However, the overall national picture remains unpublished.
Study design, size, duration: Cohort study from 1990 to 2010 of all ART cycles in Belgium (2685 cycles in 1990 evolving to 19 110 cycles in 2010), with a retrospective analysis from 1990 to 2000 and prospective online data collection since 2001.
Participants/materials, setting, methods: Registration evolved from paper written reports per centre to a compulsory online registration of all ART cycles. From 2001 up to mid-2009, data were collected from Excel spread sheets or MS Access files into an MS Access database. Since mid-2009, data collection is done via a remote and secured web-based system (www.belrap.be) where centres can upload their data and get immediate feedback about missing data, errors and inconsistencies.
Main results and the role of chance: National Belgian registration data show that reimbursement of IVF laboratory costs in July 2003, coupled to a legal limitation in the number of embryos transferred in utero, were associated with a 50% reduction of the multiple pregnancy rate from 27 to 11% without reduction of the pregnancy rate per cycle, and with an increase in the number of fresh and frozen ART cycles due to improved access to treatment.
Limitations, reasons for caution: There is potential underreporting of complications of ART treatment, pregnancy outcome and neonatal health.
Wider implications of the findings: Over the 20 years of registration, the pregnancy rate has remained constant, despite the reduction in the number of embryos transferred, optimization of laboratory procedures and stimulation protocols, introduction of quality systems and implementation of the EU Tissue Directive over the period 2004-2010.
Study funding/competing interest(s): No external funding was sought for this study. None of the authors has any conflict of interest to declare.
Keywords: Belgium; IVF; assisted reproductive technology; multiple pregnancies; registration.