Stanford, J. B., Harris, E. R., Najmabadi, S., & Smith, K. R. (2026). Potential increase of the U.S. total fertility rate resulting from restorative treatment of unresolved subfertility: a simulation study. Frontiers in Reproductive Health. https://doi.org/10.3389/frph.2026.1856175
Stanford JB, Harris ER, Najmabadi S, Smith KR. Potential increase of the U.S. total fertility rate resulting from restorative treatment of unresolved subfertility: a simulation study. Frontiers in Reproductive Health. 2026. doi:10.3389/frph.2026.1856175
Stanford, J. B., et al. "Potential increase of the U.S. total fertility rate resulting from restorative treatment of unresolved subfertility: a simulation study." Frontiers in Reproductive Health, 2026.
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A simulation projects RRM access could raise the U.S. fertility rate
A simulation of U.S. women ages 20 to 44 found that wider access to restorative reproductive medicine (RRM) could raise the U.S. fertility rate 1.0% to 14.5% in the model, depending on the scenario. The modeled couples had trouble getting pregnant. RRM birth rates came from the iNEST cohort, counting medical treatment only. Eligibility and use assumptions set the range.
About 2 in 10 women had a live birth within 1.5 years of medical treatment in the iNEST cohort. Source: Stanford JB et al., 2026, DOI 10.3389/frph.2026.1856175.Study at a glance, simulation study of U.S. women ages 20 to 44: Modeled access to RRM raised the U.S. fertility rate 1.0% to 14.5%. Source: Stanford JB et al., 2026, DOI 10.3389/frph.2026.1856175.
Key Findings
The U.S. total fertility rate was 1.77 in 2015-2019 before any change. The authors estimated that 13.5% of women aged 20-44 have trouble getting pregnant.
Lowest gain: if half would have a baby anyway, 20% used RRM, and only married women trying for 12 months or more were eligible, the rate reached 1.79 (+1.0%, absolute +0.02).
Highest gain: if a quarter would have a baby anyway, 50% used RRM, and every woman with trouble getting pregnant was eligible, the rate reached 2.02 (+14.5%, absolute +0.26), near replacement level.
Among married women with trouble getting pregnant, with 50% having a baby anyway and 50% using RRM, RRM live birth rates of 18% to 41% gave rates of 1.84 to 1.93.
In the iNEST cohort, crude live births within 1.5 years of medical treatment were 20.7% at all ages, ranging from 23.5% at ages 20-24 to 13.5% at ages 40-44.
Interpretation
This simulation study modeled U.S. fertility rate changes under different RRM eligibility and uptake assumptions, using live birth rates from the iNEST cohort. The authors call these projections theoretical. They ask for empirical studies to test them. The findings support larger studies of RRM's effect on fertility rates.
RRM Context
The authors describe RRM as finding the fertile window, working on behavioral factors, and treating the conditions behind low fertility in both partners. They state that primary care clinicians can be trained to deliver it without surgery. Roughly 2% of U.S. births follow IVF. An estimated 5% follow other fertility treatments that skip IVF. Workforce capacity, insurance coverage, and equitable access would need to change for a wider rollout.
Our editorial summary of this paper, not the article's abstract.
Abstract
Background
The total fertility rate (TFR) in most developed countries has been declining for decades. In the United States (U.S.), the total fertility rate has remained below replacement level since 2007. Subfertility affects at least 15% of women or couples over their reproductive lifespan and contributes to reduced TFR. Restorative reproductive medicine (RRM) is a medically based approach to subfertility care that can be delivered in primary care settings to increase live birth rates.
Objective
To estimate the theoretical impact of use of RRM among subfertile couples in the United States.
Methods
We conducted a simulation study. Model inputs included the number of women of reproductive age in the United States by 5-year age groups; current age-specific and total fertility rates; the proportion of women in each age group with subfertility; estimated spontaneous live birth rates among women with subfertility; and age-specific crude live birth rates with RRM treatment. We evaluated fifteen scenarios including sensitivity analyses: two different varying assumptions for live births from spontaneous conception (25% vs. 50%), two levels of RRM utilization among subfertile women (20% vs. 50%), three different estimates of the number of subfertile women who would be potentially eligible for RRM treatment, and 4 different levels of effectiveness (live birth) from RRM treatment.
Results
The baseline TFR in the United States was 1.77 during 2015-2019, and 13.5% of women ages 20-44 were estimated to have subfertility. In a conservative scenario (50% spontaneous births; 20% RRM utilization; married women trying to conceive for at least 12 months, 20.7% RRM live births), the TFR increased to 1.79, representing a 1.0% relative increase (absolute +0.02). In an optimistic scenario (25% spontaneous births; 50% RRM utilization; all subfertile women), the TFR increased to 2.02, a 14.5% relative increase (absolute +0.26), approaching replacement-level fertility.
Conclusion
Simulation results suggest that expanding access to RRM within primary care settings could meaningfully increase the U.S. TFR, by reducing unresolved subfertility. Realizing this potential would require policy and health system changes to address workforce capacity, insurance coverage, and equitable access. These findings underscore the potential contribution of non-IVF fertility care pathways in addressing population-level fertility decline.
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