Study: Patients over 35 had better prenatal care, pregnancy outcomes than those slightly younger

People giving birth over the age of 35 are considered to be of “advanced maternal age” in clinical obstetrics, and at higher risk for poor pregnancy outcomes. Now, a new study has found that patients just over age 35 had better prenatal care and pregnancy outcomes compared to those who were only a few months younger.

The study, published December 3, 2021 in JAMA Health Forum, was co-authored by Jessica Cohen, Bruce A. Beal, Robert L. Beal, and Alexander S. Beal Associate Professor of Global Health at Harvard T.H. Chan School of Public Health.

The study looked at more than 50,000 births in the U.S. from 2008 to 2019. About half of those giving birth were between 34.7 and 34.9 years old, and the other half were between 35 and 35.3. The researchers found that prenatal care—including ultrasounds, visits with maternal-fetal medicine specialists, and special monitoring of the fetus—all increased among those who were over age 35. In addition, stillbirths and early newborn deaths dropped in that group.

In a December 3 USA Today article, Cohen said her personal experience inspired the study. She noticed a difference in care when she had her second child at age 36, compared with when she had her first at age 34. “When I had the second and I noticed how carefully I was being watched I was like, ‘Wow, I wish I had this the first time,’” she said.

The authors noted that more study is needed to understand which kinds of prenatal care make the biggest difference in improving pregnancy outcomes.

Read the USA Today article: Pregnancy risks increase with age but there’s no reason to believe risks ‘jump’ after turning 35, study suggests

Read New York Times coverage: Expecting or Planning? There’s Nothing Magic About Age 35.

Listen to Freakonomics podcast: When is a ‘High-Risk’ Pregnancy a Good Thing?