Under a complete national abortion ban, the incidence of neonatal single-ventricle cardiac defects would likely increase, as would the associated resource utilization, according to a decision analysis.

Using the predictions of a decision-tree model based on pregnancy and birth data from the existing literature, neonatal single-ventricle cardiac defects would jump by 53.7%, translating to an additional nine cases per 100,000 live births, with a complete abortion ban, reported Hayley Miller, MD, of Stanford University’s Center for Academic Medicine in Palo Alto, California, and co-authors.

This increase would result in an additional 531 neonatal heart surgeries, 16 heart transplants, 77 extracorporeal membrane oxygenation (ECMO) utilizations, and 102 neonatal deaths annually, they noted in Obstetrics & Gynecology. In total, a complete abortion ban model predicted 1,517 heart surgeries, 44 heart transplants, 219 ECMO utilizations, and 291 neonatal deaths.

“Universal abortion bans will significantly increase the incidence of neonatal single-ventricle cardiac defects, associated morbidity, and resource utilization,” the authors concluded. “States considering limiting abortion access should consider the implications of such policies on the resources required to care for the increasing number of children that will be born with significant and complex medical needs, including congenital heart disease.”

Miller and team also modeled abortion bans at 13 weeks and 20 weeks of gestation. For a 13-week ban, the model predicted 1,357 heart surgeries, 40 heart transplants, 196 ECMO utilizations, and 261 neonatal deaths. A 20-week ban would result in 1,333 heart surgeries, 39 heart transplants, 192 ECMO utilizations, and 256 neonatal deaths.

Using a scenario of existing abortion restrictions prior to the 2022 Dobbs v. Jackson Women’s Health Organization Supreme Court decision that overturned Roe v. Wade, the researchers estimated 1,006 cases of single-ventricle cardiac defects — “defects in which biventricular circulation is not possible, and as a result, surgical single-ventricle palliation is indicated” — among 6,369,000 annual pregnancies.

Miller and colleagues noted that approximately 3% to 4% of pregnancies are complicated by structural birth defects, and “there are additional life-limiting fetal anomalies that would likely contribute to increased healthcare resource utilization in the setting of abortion bans, including severe neurologic anomalies, other cardiac defects, abdominal wall defects, lung lesions, and genetic syndromes.”

Most fetal anatomic anomalies are detected on ultrasound during the second trimester. Past studies have shown that many people choose to terminate their pregnancy if significant fetal anomalies are found, the authors said. Cardiac malformations are the most prevalent congenital abnormality.

David Hackney, MD, a maternal-fetal medicine doctor at Case Western Reserve University in Cleveland, said that a common anti-abortion argument is that life-threatening fetal abnormalities are rare.

“However, even statistically rare events can still have an enormous impact when extrapolated over the entire population of a country. For any individual pregnant person, the probability of a single-ventricle cardiac defect is profoundly small, but across an entire country in the scenario of a national ban, the impact is in the hundreds,” Hackney explained to MedPage Today.

He also pointed out that quantifying an issue can help inform policymakers.

“It is one thing to discuss the likely increase as a broad concept and another to give actual numbers, which then drive the point home more starkly,” said Hackney, who was not involved in this study.

He also added that this research has the same limitations as any decision analysis. “It is probably worth noting that research on outcomes or future projected resource utilization … does not exactly map to the underlying ethical concerns, as patients should have autonomy even if the clinical outcomes would be improved or if resource utilization went down instead of up,” Hackney said.

The analysis was based on current clinical pathways and known probabilities and included a theoretical cohort of 6,369,000 people, which is the approximate number of pregnancies in 2021. These pregnancies resulted in 3,664,292 live births.

Though the four national abortion legal frameworks assessed were theoretical, three of the bans were based on real proposed legislation.

The study had several limitations, including that the theoretical scenarios do not reflect all the current abortion legislation and that the model didn’t incorporate cases of single-ventricle cardiac defects caught in the first trimester. Additionally, the model did not capture the lifetime of additional healthcare resources required beyond the neonatal period. The authors also noted that the findings do not apply to neonates who aren’t surgical or biventricular candidates.