Study question: What is the impact of the Belgian legislation (1 July 2003), coupling reimbursement of six assisted reproduction technology (ART) cycles per patient to restricted embryo transfer policy, on cumulative delivery rate (CDR) per patient?
Summary answer: The introduction of Belgian legislation in ART had no negative impact on the CDR per patient based on realistic estimates within six cycles or 36 months.
What is known already: The introduction of Belgian legislation limiting the number of embryos for transfer resulted in a reduction of the multiple pregnancy rate (MPR) per cycle by 50%.
Study design, size, duration: A retrospective cohort study with a study group after implementation of the new ART legislation (July 2003 to June 2006) and the control group, before legislation (July 1999 to June 2002).
Participants/materials, setting, methods: CDR was compared in an academic tertiary setting between a study group after legislation (n = 795 patients, 1927 fresh and 383 frozen-thawed embryo transfer (FET) cycles) and a control group before legislation (n = 463 patients, 876 fresh and 185 FET cycles) within six cycles or 36 months, delivery or discontinuation of treatment. The CDR was estimated using life table analysis considering pessimistic, optimistic and realistic scenarios and compared after adjustment for confounding variables. In the realistic scenario we included information on embryo quality to define the prognosis of each patient discontinuing treatment.
Main results and the role of chance: In the realistic scenario, CDR within 36 months was comparable (all ages, P = 0.221) in study group (60.8%) and control group (65.6%), as well as in different age groups (<36 years, P = 0.242; 36-39 years, P = 0.851; 40-42 years, P = 0.840). In the realistic scenario applied to six cycles, we found lower CDRs in the study group than in the control group within the two first cycles (all ages, P = 0.009; <36 years, P = 0.007) but no difference in CDRs between the two groups within the four subsequent cycles (all ages P = 0.232; <36 years, P = 0.198). The CDR within six cycles was 60 and 65.3% for study group and control group, respectively, for all ages, and 65.8 and 70.4%, respectively, in the subgroup younger than 36 years. In women ≥36 years, CDR within six cycles was comparable in both groups (36-39 years, 43% in study versus 44.4% in control group, P = 0.730; 40-42 years, 21% in study versus 23% in control group, P = 0.786).
Limitations, reasons for caution: A retrospective cohort study design was the only way to study the impact of legislation on CDR. Owing to the retrospective nature of this analysis over a long period of time, our data are potentially influenced by improvements in techniques and therefore improved success rates in ART over time.
Wider implications of the findings: This 'Belgian model' can now be considered for application worldwide in countries with the aim to reduce the main ART side effect (high MPR) and its associated costs without a negative effect on the main intended effect (high CDR).
Study funding/competing interest(s): The authors have no conflict of interest to declare. No funding was obtained for this study.
Keywords: assisted reproduction technology; cumulative delivery rate; health policy; legislation; multiple pregnancy.