Abstract
As age at first birth continues to increase in the United States, the use of medically assisted reproduction (MAR) has likely increased. Using population-level data of births in the United States from the National Vital Statistics System from 2010 to 2021, the authors document the proportion of births due to MAR with a focus on parents 40 years or older, disaggregating by parental age combinations and parity. Although MAR-related births constitute a small proportion of all births, there is a growing and sizable proportion of first births to women 40 years or older due to MAR. Specifically, 28.2 percent, 21.5 percent, and 15.3 percent first births involved MAR among mothers 40 or older with an unknown father’s age, both parents 40 or older, and mothers 40 or older with fathers younger than 40, respectively. Thus, for some groups, MAR is a particularly important component of the pathway to parenthood.
Childbearing in the United States is increasingly delayed, with birth rates to women 40 years and older rising even while overall birth rates are falling (Osterman et al. 2023). Postponing parenthood means that more individuals and couples will experience difficulty conceiving or carrying a pregnancy to term. As a result, the use of medically assisted reproduction (MAR)—the broader term for the use of treatments such as fertility-enhancing drugs, artificial insemination, and assisted reproductive technology—has grown substantially (De Geyter et al. 2020). Given delayed childbearing, growing coverage of celebrities using MAR to have children at older ages (e.g., Cheung 2023; Dodd 2022), and the mainstreaming of related procedures such as egg freezing (Agarwal et al. 2021), the contribution of MAR to overall birth levels in the United States may be sizable, especially among births at older ages.
Methods and Results
We use data from the National Vital Statistics System from 2010 to 2021 to calculate the share of all births involving MAR and among those involving at least one parent 40 years or older. Given age patterns of partnering across gender as well as the emergence of single mothers by choice (Hertz 2006), we disaggregate across four age combinations: both parents 40 or older; only father 40 or older; only mother 40 or older; and mother 40 or older, father age unknown. We further distinguish between all births (Figure 1A) and first births (Figure 1B). The distribution for all parities and age groupings is in the supplement, along with other details about the data.
Percentage of total births due to medically assisted reproduction (MAR) for all groups and for parental age combinations with one or more parents 40 years or older by all parities (A) and parity 1 births (B).
In both Figures 1A and 1B, the black lines indicate that MAR’s overall contribution to births is quite low, accounting for 2.1 percent of all births and 2.6 percent of first births in 2021. The share of births involving MAR is much higher (and increased more over time) when the mother is 40 years or older, especially for first births. By 2021, 12.0 percent of births and 28.2 percent of first births to mothers 40 or older and fathers of unknown age involved MAR, followed by 11.2 percent and 21.5 percent, respectively, when both parents are 40 or older and 8.1 percent and 15.3 percent, respectively, of births when the mother is 40 or older and the father is younger than 40.
Conclusions
Although a very low share of U.S. births involve MAR, it is considerably higher for births to mothers 40 years or older, especially to first-time mothers. Among first births to women 40 or older, either having a birth with a partner who is also 40 or older or with a partner of unknown age (perhaps reflecting donor sperm), more than one in five involve MAR. The contribution of MAR to birth levels would likely be higher if MAR were more accessible; it remains out of reach for many because of cost (Weigel et al. 2020). Furthermore, if the age at parenthood continues to rise, we can expect the share to continue to grow, though MAR births will likely remain a low share of all births that will not fully offset fertility declines (Hoorens et al. 2007).
Supplemental Material
sj-docx-2-srd-10.1177_23780231231205191 – Supplemental material for Medically Assisted Reproduction in the United States: A Focus on Parents 40 and Older
Supplemental material, sj-docx-2-srd-10.1177_23780231231205191 for Medically Assisted Reproduction in the United States: A Focus on Parents 40 and Older by Katherine I. Tierney and Karen Benjamin Guzzo in Socius
Supplemental Material
sj-txt-1-srd-10.1177_23780231231205191 – Supplemental material for Medically Assisted Reproduction in the United States: A Focus on Parents 40 and Older
Supplemental material, sj-txt-1-srd-10.1177_23780231231205191 for Medically Assisted Reproduction in the United States: A Focus on Parents 40 and Older by Katherine I. Tierney and Karen Benjamin Guzzo in Socius
Footnotes
Acknowledgements
This research uses data from the National Center for Health Statistics. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the National Center for Health Statistics, which is responsible for only the initial data.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research was partially supported by a center grant from the Eunice Kennedy Shriver National Institutes of Child Health and Human Development to the University of North Carolina at Chapel Hill’s Carolina Population Center (P2C-HD050924).
Supplemental Material
Supplemental material for this article is available online.
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