Conceptualizing and Measuring the Contribution of Assisted Reproductive Technologies to Fertility Rates

Against the backdrop of the rising use of assisted reproductive technologies (ART), we argue that more reflection on the measurement and conceptualization of the contribution of ART to fertility rates is warranted. First, despite evidence of marked sociodemographic stratification in ART use, research on the ART contribution to fertility rates has largely overlooked how ART contributes differently to fertility levels across sociodemographic groups. Second, existing work tends to be ambiguous regarding what fertility would have looked like if ART had not been available. We demonstrate the importance of these points through period (1986–2018) and cohort (women born in 1949–1974) analyses using data from the Norwegian Population Registers. We demonstrate empirically the absolute and relative variation in the contribution of ART to fertility across sociodemographic subgroups. Whereas the relative ART contribution was highest and increasing steeply in recent years for women 40+, in absolute terms it was substantially higher for women in their thirties. Unlike natural fertility, differences in the absolute contribution of ART to the fertility of education groups were increasing over time. Then, considering a range of assumptions, we show that the “crude” contribution of ART may be either an overestimation or an underestimation compared to the “net” contribution. Our results prompt important reflections on how ART is framed in policy and scholarship.