Abortion Law and Abortion Rates

Many people – pro-life and pro-choice alike – believe that abortion restrictions don’t impact overall abortion rates. This is a myth. Relatively minor restrictions such as limits on taxpayer funding and mandatory waiting periods significantly reduce abortion rates. Abortion bans have an even greater effect. These results hold when accounting for illegal “off the books” abortions.

Below we link to research in chronological order presented over decades in a variety of publications establishing that abortion restrictions decrease abortions.

Research accounting for illegal abortions

While illegal abortions are difficult to quantify, births are more straightforward. If it were true that all people who want abortions obtain them regardless of the law, abortion laws should have no relationship to birth rates. That’s not the case. Below is a list of research that examines abortion laws in relation to birth rates, fertility rates, unintended births, and similar metrics. The research finds that greater abortion restrictions are associated with more births and more lax restrictions are associated with fewer births, suggesting that when abortions are less accessible, fewer women obtain them.

Analysis of statewide data from the three States indicated that following restrictions on State funding of abortions, the proportion of reported pregnancies resulting in births, rather than in abortions, increased in all three States.

Trends in Rates of Live Births and Abortions Following State Restrictions on Public Funding of Abortion,” Korenbrot, Brindis, & Priddy, Public Health Reports, November-December 1990, Vol. 105, No. 6

The decline in geographic access to abortion providers during the 1980s accounted for a small but significant portion of the rise in the percentage of women heading families.

State abortion policy, geographic access to abortion providers and changing family formation,” Lichter, McLaughlin, & Ribar, Family Planning Perspectives, Nov-Dec 1998:30(6):281-7

States legalizing abortion experienced a 4% decline in fertility relative to states where the legal status of abortion was unchanged.

Roe v Wade and American fertility,” Levine, Staiger, Kane, & Zimmerman, American Journal of Public Health, 1999 February; 89(2): 199-203

Our results indicate that much of the reduction in fertility at the time abortion was legalized was permanent in that women did not have more subsequent births as a result.

Abortion Legalization and Life-Cycle Fertility,” Ananat, Gruber, & Levine, The Journal of Human Resources, Vol. 42, No. 2 (Spring, 2007) pp375-397

Overall, the results show that laws that increased minors’ access to abortion in the 1960s and 1970s had a larger impact on minors’ birthrates than laws that increased oral contraceptive access.

Fertility Effects of Abortion and Birth Control Pill Access for Minors,” Guldi, Demography, v.45(4); 2008 Nov

Approximately one-fourth of women who would have Medicaid-funded abortions instead give birth when this funding is unavailable … Studies have found little evidence that lack of Medicaid funding has resulted in illegal abortions.

Restrictions on Medicaid Funding for Abortions: A Literature Review,” Henshaw, Joyce, Dennis, Finer, & Blanchard, Guttmacher Institute, June 2009

Robustness tests supported the association between access to abortion and decreased birthrates, while the relationship between access to the pill and birthrates received less support.

Abortion or Pill Access Is Associated with Lower Birthrates Among Minors,” Thomas, Perspectives on Sexual and Reproductive Health, Volume 41, Issue 1, March 2009, Page 65

Minors in states with mandatory waiting periods were more than two times as likely to report an unintended birth.

How Are Restrictive Abortion Statutes Associated With Unintended Teen Birth?” Coles, Makino, Stanwood, Dozier, & Klein, Journal of Adolescent Health, Volume 47, Issue 2, August 2010, Pages 160-167

[If Roe v. Wade were overturned] abortion rates would fall by 14.9 percent nationally, resulting in at most, 178,800 additional births or 4.2 percent of the U.S. total in 2008. A ban in 17 states would result in a 6.0 percent decline in abortions and at most, 1.7 percent rise in births.

Back to the Future? Abortion Before & After Roe,” Joyce, Tan, & Zhang, National Bureau of Economic Research, August 2012

We estimated that each year more than 4000 US women are denied an abortion because of facility gestational limits and must carry unwanted pregnancies to term.

Denial of Abortion Because of Provider Gestational Age Limits in the United States,” Upadhyay, Weitz, Jones, Barar, & Foster, American Journal of Public Health, 2014, 104, 1687_1694

I estimate an increase in the birthrate of 4% to 12% when abortion is restricted. In the absence of anti-abortion laws, fertility would have been 5% to 12% lower in the early twentieth century.

The Effect of Anti-Abortion Legislation on Nineteenth Century Fertility,” Laney, Demography, 2014 Jun; 51(3): 939-948

This [ultrasound] law caused an increase in viewing rates and a statistically significant but small increase in continuing pregnancy rates.

Evaluating the impact of a mandatory pre-abortion ultrasound viewing law: A mixed methods study,” Upadhyay, Kimport, Belusa, Johns, Laube, & Roberts, PLoS One. 2017; 12(7); e0178871

We estimate that over the past 25 years, parental involvement laws have resulted in half a million additional teen births.

Did Parental Involvement Laws Grow Teeth? The Effects of State Restrictions on Minors’ Access to Abortion,” Myers & Ladd, Social Science Research Network, 31 Aug 2017

(See an SPL blog post about this specific paper here.)

Participants were asked if they had considered abortion for this pregnancy and, if so, reasons they did not obtain one…more participants who had considered abortion in Louisiana than Maryland reported a policy-related reason (primarily lack of funding for the abortion) as a reason (22% Louisiana, 2% Maryland, p < 0.001).

Consideration of and Reasons for Not Obtaining Abortion Among Women Entering Prenatal Care in Southern Louisiana and Baltimore, Maryland,” Roberts, Kimport, Kriz, Holl, Mark & Williams, Sexuality Research and Social Policy, 16, 476-487 (2019)

29% of Medicaid eligible pregnant women who would have an abortion with Medicaid coverage, instead give birth.

Estimating the proportion of Medicaid-eligible pregnant women in Louisiana who do not get abortions when Medicaid does not cover abortion,” Roberts, Johns, Williams, Wingo, & Upadhyay, BMC Women’s Health, 19, 78 (2019)

Greater exposure to ARs [abortion restrictions] was associated with increased risk of UIB [unintended birth].

Implications of Restrictive Abortion Laws on Unintended Births in the U.S.: A Cross-Sectional Multilevel Analysis,” Rice & Hall, Rollins School of Public Health, Emory University, from APHA’s 2019 Annual Meeting and Expo, November 2019

We examine characteristics and experiences of women who considered, but did not have, an abortion for this pregnancy….Interviewees who considered abortion and were subject to multiple restrictions on abortion identified material and instrumental impacts of policies that, collectively, contributed to them not having an abortion.

Complex situations: Economic insecurity, mental health, and substance use among pregnant women who consider – but do not have – abortions,” Roberts, Berglas, & Kimport, PLoS ONE, 15(1): e0226004, January 2020

We find that a 100-mile increase in distance to the nearest clinic is associated with 30.7 percent fewer abortions and 3.2 percent more births.

Undue Burden Beyond Texas: An Analysis of Abortion Clinic Closures, Births, And Abortions in Wisconsin,” Venator & Fletcher, Journal of Policy Analysis and Management, Volume 40 Issue 3, 03 November 2020

Restrictive state-level abortion policies are associated with not having an abortion at all.

State abortion policies and Medicaid coverage of abortion are associated with pregnancy outcomes among individuals seeking abortion recruited using Google Ads: A national cohort study,” Upadhyay, McCook, Bennett, Cartwright, & Roberts, Social Science & Medicine, Volume 274, April 2021

Research not accounting for illegal abortions

Below is a list of research that examines abortion restrictions in relation to abortion rates and finds that increased restrictions are associated with decreased rates and vice-versa. However, this research does not explicitly account for changes in illegal abortion rates. We want to be transparent about that context, although the results below would be consistent with the research listed above which did account for potential illegal abortions.

If all states observed the Hyde Amendment restrictions, many thousands of Medicaid-eligible women who would have obtained abortions under the 1977 funding policy would not receive them.

The impact of restricting Medicaid financing for abortion,” Trussell, Menken, Lindheim, & Vaughan, Family Planning Perspectives, May-Jun 1980; 12(3):120-3, 127-30

The data show that 13% fewer had abortions in August through December than would have been expected on the basis of the number who had abortions in January through July.

The Effects of Mandatory Delay Laws On Abortion Patients and Providers,” Althaus & Henshaw, Family Planning Perspectives, Vol. 26, No. 5 (Sep-Oct 1994)

A maximal estimate suggests that 22 percent of the abortions among low-income women that are publicly funded do not take place after funding is eliminated.

State abortion rates the impact of policies, providers, politics, demographics, and economic environment,” Blank, George, & London, Journal of Health Economics, Volume 15, Issue 5, October 1996, pages 513-553

Access variables, including the restrictiveness of state laws regulating abortion, state funding of abortions for poor women and the availability of hospital abortions, affect abortion rates directly.

The role of access in explaining state abortion rates,” Gober, Social Science & Medicine, Volume 44, Issue 7, April 1997, Pages 1003-1016

The incidence of abortion is found to be lower in states where access to providers is reduced and state policies are restrictive.

The effects of economic conditions and access to reproductive health services on state abortion rates and birthrates,” Matthews, Ribar, & Wilhelm, Family Planning Perspectives, Mar-Apr 1997; 29(2):52-60

The Texas parental notification law was associated with a decline in abortion rates among minors from 15 to 17 years of age.

Changes in Abortions and Births and the Texas Parental Notification Law,” Joyce, Kaestner, & Colman, The New England Journal of Medicine 2006; 354:1031-1038

A series of regressions on a comprehensive time series cross-sectional data set provides evidence that several types of state-level anti-abortion legislation result in statistically significant declines in both the abortion rate and the abortion ratio.

Analyzing the Effect of Anti-Abortion U.S. State Legislation in the Post-Casey Era,” New, State Politics & Policy Quarterly, Vol 11, Issue 1, 2011

The empirical results add to the substantial body of peer-reviewed research which finds that public funding restrictions, parental involvement laws, and properly designed informed consent laws all reduce the incidence of abortion.

Analyzing the Impact of U.S. Antiabortion Legislation in the Post-Casey Era: A Reassessment,” New, State Politics & Policy Quarterly, Vol 14, Issue 3, 2014

We found that a 100-mile increase in distance to the nearest abortion facility was associated with a 10% decrease in the overall abortion rate.

Abortion Facility Closings and Abortion Rates in Texas,” Quast, Gonzalez, Ziemba, INQUIRY: The Journal of Health Care Organization, Provision, and Financing. January 2017.

Counties with no facility in 2014 but no change in distance to a facility between 2012 and 2014 had a 1.3% (95% CI, −1.5% to 4.0%) decline in abortions. When the change in distance was 100 miles or more, the number of abortions decreased 50.3% (95% CI, 48.0% to 52.7%).

Change in Distance to Nearest Facility and Abortion in Texas, 2012 to 2014,” Grossman, White, & Hopkins, JAMA, 2017;317(4):437-439

Increases in distance have significant effects for women initially living within 200 miles of a clinic. The largest effect is for those nearest to clinics for whom a 25-mile increase reduces abortion 10%.

How Far is Too Far? New Evidence on Abortion Clinic Closures, Access, and Abortions,” Cunningham, Lindo, Myers, & Schlosser, Social Science Research Network, April 2017

Trends in sexual behavior suggest that young women’s increased access to the birth control pill fueled the sexual revolution, but neither these trends nor difference-in-difference estimates support the view that this also led to substantial changes in family formation. Rather, the estimates robustly suggest that it was liberalized access to abortion that allowed large numbers of women to delay marriage and motherhood.

The Power of Abortion Policy: Reexamining the Effects of Young Women’s Access to Reproductive Control,” Myers, Journal of Political Economy, Volume 125, Number 6, December 2017

…the abortion rate is predicted to fall by 32.8% (95% confidence interval 25.9-39.6%) in the year following a Roe reversal.

Predicted changes in abortion access and incidence in a post-Roe world,” Myers, Jones, & Upadhyay, Contraception, 2019 Nov; 100(5): 367-373

A highly restrictive policy climate, when compared with a less restrictive one, was associated with a significantly lower abortion rate by 0.48 abortions per 1000 women, representing a 17% decrease from the median abortion rate of 2.89 per 1000 women.

Association of Highly Restrictive State Abortion Policies With Abortion Rates, 2000-2014,” Brown, Hebert, & Gilliam, JAMA Network, 2020;3(11):e2024610

A note on international comparisons

The above research focuses on the United States. Frequently people will point to international trends, citing an apparent lack of correlation between abortion laws and abortion rates as evidence that laws don’t decrease rates. These comparisons typically fail to account for confounding variables, most notably unintended pregnancy rates. Often the same countries with stricter abortion laws have higher unintended pregnancy rates. The law decreases abortion while the higher unintended pregnancy rate increases it, so the two factors have mitigating outcomes that mask their individual effects. When we control for unintended pregnancy rates, data indicate abortion laws decrease abortion rates even on an international scale. Our Executive Director, Monica Snyder, discusses this phenomenon in detail in her presentation “Deconstructing Three Pro-Choice Myths,” which you can view here. You can also read more in her post “Abortion laws decrease abortion rates internationally, but high unintended pregnancy rates can mask this effect.