Sex-selective abortion bans (SSABs) - which prohibit the seeking of abortions based on the fetus' sex - increase the likelihood of low birth weight and preterm births among infants born to Asian immigrant mothers, according to a new study by Yale sociologist Emma Zang.
The study also shows that the bans, which are law in 14 U.S. states, do not affect male-female sex ratios among infants born to these mothers, undermining the rationale behind them, Zang said.
Critics of the laws argue that proponents have invoked stereotypes about Asian immigrants holding a preference for male children.
"Advocates for sex-selective abortion bans often have justified them by invoking xenophobic stereotypes that frame Asian cultures and immigrants as incompatible with American values of gender equality," said Zang, associate professor of sociology, biostatistics, and global affairs in Yale's Faculty of Arts and Sciences and the Yale Jackson School of Global Affairs. "Our findings link these bans to negative birth outcomes for Asian immigrant women and show they do nothing to achieve their stated purpose of reducing sex-selective practices. They suggest that the bans stigmatize Asian immigrants, fostering a hostile social environment that harms maternal and infant health."
The researchers found that the probability of low birth weight (newborns weighing less than 5 pounds, 8 ounces) and preterm birth (infants born before 37 weeks of pregnancy) increased by 0.3 and 0.5 percentage points, respectively, among Asian immigrant mothers in states with SSABs, compared to other foreign-born mothers. This translates to an additional 1,086 infants with low birth weight and 1,810 preterm births among the 362,045 children born to Asian immigrant mothers in six states with SSABs that were examined for the study.
Prior research, the study's authors say, has demonstrated that pregnant women respond to external stressors, such as those caused by living in a hostile social environment, with fluctuations in blood pressure, inflammation, and other biomarkers that can negatively affect the mental and physiological development of fetuses. SSABs effectively create a hostile social environment for Asian immigrant women, Zang said.
The study also found no evidence that the bans affected the male-female ratio for infants born to Asian immigrant mothers relative to all other immigrant mothers.
The study, published in the journal Social Science & Medicine, is only the second to empirically investigate the effects of SSABs, which prohibit doctors from performing an abortion if they suspect the patient is seeking the procedure due to a preference for the sex of the fetus. It focused on six states that enacted bans between 2010 and 2014: Oklahoma, Arizona, Kansas, North Carolina, North Dakota, and South Dakota.
For the study, Zang and her co-authors analyzed birthrate data from the National Vital Statistics System, a federal database compiled annually that provides information on all registered U.S. births. Their dataset included all single-infant births to foreign-born mothers residing in the United States between 2005 and 2019, accounting for more than 12 million births.
Several of the states with bans in place have experienced rapid growth in Asian immigrant populations over the past decade, including South Dakota, North Dakota, and North Carolina, the researchers said. They cited specific examples in which legislators advocating for SSABs used rhetoric rooted in racial stereotypes that paint Asian immigrants as culturally irreconcilable with U.S. norms.
"These laws are distinct in the way they co-opt feminist rhetoric to justify abortion restrictions, framed as measures to combat gender discrimination while simultaneously reinforcing xenophobic stereotypes," the researchers note.
Empirical evidence does not support the claim that sex-selective abortion is widespread in the United States, even among groups historically associated abroad with a preference for sons, they added. They acknowledge that modern reproductive technologies, such as sperm sorting and pre-implantation genetic diagnosis, offer alternative means for sex selection that SSABs do not regulate.
"Our work demonstrates how SSABs and other symbolic policies - those primarily meant to convey a message rather than address a real-world problem - can have serious consequences on people's health and well-being, particularly when they are motivated by fear of foreign 'others,'" Zang said. "It also underscores the need for more nuanced policy discussions in the United States surrounding abortion access, anti-Asian stigma, and immigration."
The study was co-authored by Keitaro Okura, a graduate student in Yale's Department of Sociology, and Melissa Tian, a 2024 graduate of Yale College and former research assistant in the Department of Sociology.
