Very little is known about the numbers of women who give birth behind bars each year.

In 2016, there were more than 111,000 women in American prisons, an almost 800 percent increase from 1980. Yet the number of women who enter prison pregnant ― and the outcomes of their pregnancies ― is entirely unknown as no federal agency tracks that information.

Now, a first-of-its-kind study conducted by Carolyn Sufrin, assistant professor of gynecology and obstetrics at the Johns Hopkins University School of Medicine, is starting to fill in the gaps.

From 2016 to 2017, Sufrin collected data on pregnancy in 22 state prison systems and the Federal Bureau of Prisons, which together encompassed 57 percent of all women in prison in the U.S.

The results of her study, which were published on Thursday in the American Journal of Public Health, offer a snapshot of a relatively unseen phenomenon, hidden from the public by prison walls.

“Incarcerated women are one of the most marginalized groups of people in our country,” Sufrin said, noting that the majority are in their childbearing years and already are mothers. “The utter lack of data we have [on pregnancy behind bars] is problematic and reflects more broadly the neglect of this population.”

For the study, Sufrin persuaded corrections officials across the country to voluntarily report the number of female prisoners who were pregnant and the number of births, miscarriages, abortions, stillbirths and other pregnancy outcomes over the course of a year.

Three states with large prison populations ― New York, California and Florida ― declined to participate.

Over the course of one year, 1,396 pregnant women were admitted to state and federal prisons. A one-month snapshot in December 2016 found that 3.8 percent of newly admitted women and 0.6 percent of all incarcerated women were pregnant.

Of the pregnancies tracked, 92 percent resulted in a live birth. Six percent of women miscarried. One percent chose to terminate their pregnancies, and a half percent had a stillbirth.

The low number of abortions was striking, Sufrin said. In the general population, approximately 19 percent of pregnancies end in termination.

“It’s quite possible that there were women who wanted abortions but had difficulty accessing them,” she said, noting that prisoners have a constitutional right to abortion.

The miscarriage rate was slightly lower among incarcerated women than the general public. But she cautioned that the discrepancy could be due to female prisoners miscarrying before they knew they were pregnant. Prisons that administered pregnancy tests when women were first admitted reported higher rates of miscarriage, she said.

About 30 percent of babies were delivered via cesarean section, which aligns with national statistics.

Gaps In Reporting

There is scant official data on pregnancy in prison. Federal agencies that track birth data, like the National Center for Health Statistics, don’t gather those numbers from prisons. The Bureau of Justice Statistics, which collects data on incarceration trends, has not previously tracked pregnancies or births during custody. But the First Step Act, which became law in December, does require the agency to begin reporting the number of female prisoners “known by the Bureau of Prisons to be pregnant” and the outcomes of those pregnancies.

Women in prison tend to have high rates of poverty and substance abuse, putting them at greater risk for poor pregnancy outcomes, said Caroline Sten Hartnett, a demographer at the University of South Carolina. And prison itself is stressful, which is also bad for pregnancy outcomes.

Sufrin’s study is an important start, but it also “reveals how much there is left to do,” Hartnett said. She would like to see more research examining the quality of care that female prisoners are receiving and the health of the babies born.

“These women are under the care and guardianship of the government, and the government has a responsibility to make sure they get what they need in order to be safe and healthy,” Hartnett said.

Moreover, she said, “If we are interested in reducing health disparities as a society, we need to know what is going on with the most disadvantaged women.”

Only The Beginning

Sufrin, who began her career working as an OB-GYN at a jail in San Francisco and wrote a book about her experience there, said she plans to publish more research from her study soon.

She said she hoped her data will be used by other researchers and lawmakers to advocate for additional policy changes. Ideally, she said, the public will gain greater awareness about the not-insignificant number of women who are pregnant behind bars and will think about what that experience is like.

Neel Shah, an OB-GYN and professor at Harvard Medical School, called the study a breakthrough moment.

“It raises a number of really important questions about the capacity of our prison system to treat these folks with basic human dignity, let alone safety,” he said. “In medical ethics, pregnant women are considered a vulnerable population. Prisoners are considered a vulnerable population. You put them together, and these are some of the most vulnerable human beings out there.”