Martha Bailey · National Bureau of Economic Research 2022 · Retrospective population registry analysis · n=?

The Covid-19 Baby Bump: The Unexpected Increase in U.S. Fertility Rates in Response to the Pandemic

Cited 128 times in the scientific literature.

Level 3 - non-randomized controlled study

Level by design analogy (non-clinical): retrospective population-level longitudinal registry study.

OpenAlex W4306648520 · doi:10.3386/w30569 · record verified 2026-08-28

What was done

Researchers analyzed restricted natality microdata covering all recorded births in the United States from 2015 to 2021, alongside California birth records extending through August 2022, to assess fertility rate shifts associated with the COVID-19 pandemic across different maternal demographics.

What was found

The abstract reports directional trends without exact numerical rates or percentages. Births among foreign-born mothers dropped immediately following initial lockdowns in 2020 (timing consistent with reduced travel rather than altered conception rates). Conversely, a small 'baby bump' occurred among U.S.-born mothers in 2021, representing the first major reversal in declining U.S. fertility rates since 2007. The increase was most pronounced for first births, mothers younger than 25, and college-educated mothers aged 30–34. California records indicated that elevated birth levels persisted through the third quarter of 2022.

Why it matters

Contrary to early expectations of a prolonged pandemic-induced baby bust, the findings demonstrate a demographic rebound in U.S. fertility, potentially driven by accelerated family formation in younger women and work-from-home flexibility among college-educated mothers.

Limits

The abstract does not report exact numerical effect sizes, percentage changes, or confidence intervals. Because the study relies on administrative birth records, proposed mechanisms—such as the influence of working from home or changes in travel patterns—are inferred rather than directly measured at the individual level.

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