Demographic impact of In Vitro Fertilization in Spain

Abstract

In this paper, we analysed In Vitro Fertilization (IVF) data from the registry of the Spanish Society of Fertility (SEF). This registry is not complete until 2014, when it started to be mandatory, as a part of the clinics did not report until that year. Also, information on patients is very limited. Our first purpose was to estimate the number of births obtained by IVF in Spain for the period 1999–2019, correcting for non-participation. In this sense, we stressed the importance of estimating the number of pregnancies with unknown evolution and the demand for IVF by non-resident women in the country, to arrive at a correct estimate of the weight of IVF in total births. We also discuss what kind of improvements could make this registry more useful, for the purposes of demographic and social analysis, but also to be able to better measure the effectiveness of these techniques. This paper shows the limits of having only aggregated data. In the near future, the SEF registry will become individual, and it is hoped that it can be even more useful in determining the impact of IVF and to what degree public demand is fulfilled.

Background and objectives

The registry of In Vitro Fertilization (IVF) in Spain is not complete until 2014. Here we reconstruct the series of cycles for the period 1999–2019 correcting for non-participation which allows us to estimate the weight of births from IVF in Spain, taking also into account pregnancies with unknown evolution as well as the demand of women residing abroad. We also discuss what kind of improvements could make this registry and the corresponding reports made by the Sociedad Española de Fertilidad (SEF) more useful, for the purposes of demographic and social analysis, in the light of the transition to an individual registry in upcoming years.

Materials and methods

We use SEF reports on IVF and information on comparable registries for other countries and for Catalonia. We use also the Spanish Fertility Survey of 2018 to check the results of our estimates.

Results

We estimate that in year 2019 around 6.5% of births in Spain correspond to IVFs, very close to the figure for Denmark, the European country with the highest level. The proportion of deliveries lost to follow-up was high in the 2000s, over 20%, but lowered in the 2010s down to less than 10% and we estimate that in year 2019 around 35% of cycles were for women residing abroad. These estimates correlate well with what we observe from the Spanish Fertility Survey of 2018.

Conclusions

Using data on IVF in Spain for demographic analysis is harder than it should be, which forces to conduct a very thorough analysis of the reports and to make guess estimates in order to obtain useful results. Also, the aggregate nature of the registry considerably limits the analysis. We hope that the individual register which will start hopefully in 2022 or 2023 will help in improving the quality of the research on factors and characteristics of IVF in Spain.