Projecting the Contribution of Assisted Reproductive Technology to Completed Cohort Fertility

Abstract

Assisted reproductive technology (ART) is increasingly influencing the fertility trends of high-income countries characterized by a pattern of delayed childbearing. However, research on the impact of ART on completed fertility is limited and the extent to which delayed births are realized later in life through ART is not well understood. This study uses data from Australian fertility clinics and national birth registries to project the contribution of ART for cohorts of women that have not yet completed their reproductive life and estimate the role played by ART in the fertility 'recuperation' process. Assuming that the increasing trends in ART success rates and treatment rates continue, the projection shows that the contribution of ART-conceived births to completed fertility will increase from 2.1% among women born in 1968 to 5.7% among women born in 1986. ART is projected to substantially affect the extent to which childbearing delay will be compensated at older ages, suggesting that its availability may become an important factor in helping women to achieve their reproductive plans later in life.

Supplementary information: The online version contains supplementary material available at 10.1007/s11113-023-09765-3.

Keywords: Assisted reproductive technology; Australia; Cohort fertility; Fertility postponement; Fertility projections; Fertility recuperation.

Fig. 1

Share of women wishing to have at least one (more) child by age group and parity, Australia, 2001–2018. Source: Authors’ computations based on Household Income and Labour Dynamics in Australia (HILDA) survey, waves 1–18, release 18 (weighted)

Fig. 2

Causal loop diagram showing the contribution of ART treatment rates, ART success rates and childbearing postponement to ART births and to the total number of births. A balancing loop (B) stabilizes a component of the system while a reinforcing loop (R) reinforces such component. The “ + ” sign indicates a positive relationship between variables, while the “ − “ sign indicates a negative relationship between variables

Fig. 3

A simplified scheme of postponement and recuperation, indicating the potential contribution of ART. The design is inspired by Sobotka et al., (Fig. 1, p. 422) and adapted by the authors to show how accessibility to ART affects the demographic processes of fertility postponement and recuperation

Fig. 4

Estimated (2006–2009), observed (2010–2017) and projected (2018–2022) ART age-specific success rates A and ART age-specific treatment rates B. Due to the small number of ART births after age 45, the data for computing success rates at age 46–49 are aggregated. Results are obtained using Eq. (3). Source: Authors’ computations based on ANZARD and ABS data

Fig. 5

Observed (1968) and projected (1969–1986) percentage ART contribution to CFR. See section “Projection scenarios of ART fertility rates” for a detailed description of each scenario’s assumptions. Source: Authors’ computations based on ANZARD and ABS data

Fig. 6

Observed (1968) and projected (1969, 1974, 1980, 1986) percentage ART contribution to age-specific fertility rates. Projected values are obtained using the extrapolated success and treatment rates Scenario (S4). Source: Authors’ computations based on ANZARD and ABS data

Fig. 7

Projected cumulated cohort fertility of women born in 1974, 1980, and 1986 compared to the observed reference cohort (born in 1968), Scenario 4. Completed fertility of the reference cohort does not include ART births. Source: Authors’ computations based on ANZARD and ABS data. Source: Authors’ computations based on ANZARD and ABS data