Texas’ 2021 Ban on Abortion in Early Pregnancy and Changes in Live Births

Abstract

This study evaluates changes in the number of births in Texas after passage of Texas’ Senate Bill 8 (SB8), which bans abortions as early as 5 weeks’ gestation.

Texas’ Senate Bill 8 (SB8) became law on September 1, 2021, banning abortions as early as 5 weeks after the start of one’s last menstrual period. In the first month after SB8 went into effect, the total number of facility-based abortions provided to pregnant Texas residents in Texas or 1 of the 6 adjacent states decreased by 38% (2171 fewer abortions).¹ Many have speculated that as abortion becomes more difficult to access, people will be forced to carry pregnancies to term, thereby increasing births. However, no studies, to our knowledge, have examined fertility changes related to recent abortion restrictions. This study evaluated changes in the number of births in Texas associated with Texas’ SB8 policy.

Methods

We used publicly available monthly counts of live births in all 50 states plus the District of Columbia for 2016 through 2022 from National Center for Health Statistics birth certificate data.^2,3 The Johns Hopkins University Bloomberg School of Public Health institutional review board deemed this study exempt from ethical review.

We used a comparative interrupted time series with an augmented synthetic control approach to estimate differences between observed birth counts and counterfactual predictions of expected birth counts in Texas without SB8.⁴ This approach used a weighted combination of states to create a synthetic “Texas” based on prepolicy (January 2016-March 2022) outcome and covariate trends. The covariates included the percentage of monthly births to birthing people who were non–US-born Hispanic, non-Hispanic Black, aged 35 years or older, college educated, and using Medicaid. We also used state fixed effects to account for unobserved state-specific factors. We treated births in April 2022 as the first birth cohort exposed to the policy change because they (if full term) were at most 7 to 10 weeks’ gestation when SB8 went into effect on September 1, 2021. To evaluate whether our Texas results could be explained by a factor other than SB8 that was influencing fertility more broadly, we conducted 50 separate placebo tests in which we considered all states (and the District of Columbia) other than Texas as the “treated” state. We also confirmed that none of the states most heavily weighted in our synthetic control enacted new abortion restrictions during the relevant exposure period. We determined statistical significance by whether the 95% CI of the difference between the observed and predicted number of monthly births included 0; 95% CIs were estimated with a conformal inference procedure.⁵ All analyses were performed in R version 4.3.0 with the AugSynth package.⁴

Results

We estimated that the SB8 policy was associated with 9799 additional births in Texas between April and December 2022 (observed births, 297 088; expected births based on counterfactual estimate, 287 289). We detected increases in monthly birth counts above expectation of 1.7% to 5.1%, although April, May, and July differences were not significant (Table; Figure). The largest difference occurred in December 2022, with 1674 (95% CI, 671.7-2675.2) births occurring above the predicted 32 913. Placebo test results indicate this pattern was only evident in Texas.

Table. Estimated Difference in Observed vs Expected Births in Texas in Months Affected by Senate Bill 8^a.

Month	Observed births	Expected births	Difference (95% CI)	% Increase (95% CI)
April	29 757	29 263.0	494.0 (−412.4 to 1495.7)	1.7 (−1.4 to 5.3)
May	30 387	29 887.2	499.8 (−406.5 to 1501.5)	1.7 (−1.4 to 5.2)
June	32 127	30 707.0	1420.0 (513.7 to 2421.7)	4.6 (1.6 to 8.2)
July	33 494	32 849.8	644.2 (−262.2 to 1645.9)	2.0 (−0.8 to 5.2)
August	36 539	35 005.9	1533.1 (436.0 to 2630.3)	4.4 (1.2 to 7.8)
September	33 799	32 433.3	1365.7 (459.3 to 2367.4)	4.2 (1.4 to 7.5)
October	33 018	31 919.2	1098.8 (97.1 to 2100.6)	3.4 (0.3 to 6.8)
November	33 381	32 311.4	1069.6 (67.9 to 2071.4)	3.3 (0.2 to 6.6)
December	34 586	32 912.5	1673.5 (671.7 to 2675.2)	5.1 (2.0 to 8.4)

^a Observed birth data are for 2022 from the National Center for Health Statistics. Expected birth counts and corresponding statistics were calculated using a comparative interrupted time series with an augmented synthetic control approach.

Figure. Monthly Differences in the Number of Observed vs Expected Births in Texas, January 2016-December 2022.

Horizontal line at 0 indicates no difference between the observed and expected number of monthly births; dotted vertical line is March 2022, corresponding to the last birth cohort not exposed to Texas’ Senate Bill 8 that was used to generate the exposure period counterfactual; shading indicates the 95% CI in the policy exposure period. Observed birth data were from the National Center for Health Statistics. Expected birth counts and corresponding statistics were calculated using a comparative interrupted time series with an augmented synthetic control approach.

Discussion

This study found a greater than expected number of births in Texas in the months after a restrictive abortion law went into effect. Although there was an increase in abortions provided to Texans out of state¹ and requests for medication abortion pills obtained outside the formal health care system,⁶ results suggest not everyone who might have received an abortion in the absence of SB8 was able to obtain one.

Limitations include the use of aggregate provisional birth count data from 2022 that lack information on birthing people’s characteristics.² Additionally, results cannot be generalized because the analysis was restricted to 1 state.

Since the Supreme Court’s 2022 Dobbs v Jackson Women’s Health Organization decision, Texas has prohibited nearly all abortions, as have most neighboring states that provided key abortion access during the initial months of SB8. It is therefore crucial to continue closely monitoring any increases in the number of births that result from abortion restrictions because this may signal a curtailing of reproductive autonomy.

Section Editors: Jody W. Zylke, MD, Deputy Editor; Kristin Walter, MD, Senior Editor.

Supplement.

Data Sharing Statement