The U.S. infant mortality rate rose last year for the first time in two decades. The rate refers to the number of infants who died before their first birthdays out of every 1,000 live births.

The U.S. recorded 5.6 infant deaths per 1,000 live births in 2022, a 3% increase over the previous year, according to a report Wednesday from the Centers for Disease Control and Prevention.

The last year-to-year increase was from 2001 to 2002, when the rate similarly rose by 3%.

The 2022 data are estimates based on birth and death records submitted to the CDC’s National Center for Health Statistics. The CDC will most likely release a final report next year following a more comprehensive review of the data.

According to Danielle Ely, a co-author of the report and a health statistician at the health statistics center, “there were a number of states that had increases in the number of infant deaths and in their rates from 2021 to 2022.”

But the rise in infant mortality rates was most pronounced in four states, she said: Georgia, Iowa, Missouri and Texas.

Reproductive health experts who weren’t involved in the CDC report have a few theories about why the trend reversed course last year.

According to Dr. Pat Gabbe, a clinical professor of pediatrics at the Ohio State University Wexner Medical Center, some pregnant people may not have received proper medical care during the Covid pandemic because they were seeing doctors virtually or hesitated to visit hospitals for pregnancy complications.

“Every time we’ve measured infant mortality, it has trended down, and what’s changed? Covid. It’s disrupted all the community support we developed that helped women access prenatal care,” Gabbe said.

The pandemic also led to job loss and economic instability, which can increase stress levels among pregnant people, said Martine Hackett, an associate professor of health professions at Hofstra University.

“One of the leading factors that contribute to babies born too small and babies born too early is stress,” Hackett said.

But Dr. Tracey Wilkinson, an associate professor of pediatrics at the Indiana University School of Medicine, said the increase in infant mortality is a byproduct of ending the constitutional right to abortion. Georgia, Missouri and Texas all instated new abortion bans around the time Roe v. Wade was overturned in June 2022.

“I look at this data and it breaks my heart as a pediatrician, of course. But I also could tell you that anybody who’s in the reproductive health space could and did warn that this is the type of data we were going to start seeing when we took away the federal protections to abortion access,” Wilkinson said.

Why are infants dying?

Birth defects are the leading cause of infant deaths, followed by preterm births (before 37 weeks’ gestation) and low birth weight. But those rates didn’t change much in 2022, according to the CDC report.

Instead, the report found an increase in infants who died from pregnancy complications, such as the cervix’s opening too early or the amniotic sac’s rupturing before labor begins. Such complications can lead to premature birth, miscarriage or infection.

The report also detected an increase in the number of infants who died from bacterial sepsis — a life-threatening response to infection — in 2022.

Hackett said the fatal health outcomes could be triggered by stress during pregnancy, while Wilkinson said they’re likely to be driven by limited access to specialists who can treat complicated pregnancies.

Around 2.2 million women of childbearing age and nearly 150,000 babies live in counties where there are no hospitals or birth centers that offer obstetric care or have obstetric providers, according to a report last year from March of Dimes, a nonprofit group that researches premature birth.

“While some of those places could probably deliver a straightforward, non-complicated pregnancy, the minute it becomes complicated, you are not going to have the expertise within that building to care for either the pregnant person or the infant,” Wilkinson said.

Specialists are becoming even less available now that abortion bans limit certain types of reproductive care, she added.

“We’re starting to see graduating medical students choose not to go into OBGYN, and then we’re starting to see OBGYN residents choose not to train in states where it is hard for them to get comprehensive training,” Wilkinson said.

Rates rose for white babies despite higher overall rates for Black infants

Overall, the U.S. infant mortality rate has been declining for at least a century, but racial disparities persist: Black infants still die at more than twice the rate of white infants, and they are nearly four times more likely to die from complications related to low birth weight.

In 2022, infants born to Black women had a mortality rate of 10.9 per 1,000 live births, though the rate didn’t increase measurably compared to 2021.

Infants born to white women, on the other hand, had a mortality rate of 4.5 per 1,000 live births — a nearly 4% increase.

Infant mortality rates also rose last year for male infants, infants born to women ages 25 to 29 and preterm infants, according to the CDC report.

Reproductive health experts said male babies have historically been more vulnerable to early death than female babies, perhaps because they are biologically more susceptible to diseases or more likely to be born prematurely.

But the rise among white babies and babies born to women in their late 20s is unusual, they said, and it may be driven by the same factors that influenced the national trend.

Experts predicted that infant mortality would also rise this year, because many people still have limited access to prenatal care. The 12-month period ending in March of this year had a higher infant mortality rate than the 12-month period ending in March 2022, according to CDC data.

“We have to be committed to turning this back,” Gabbe said. “There’s no excuse.”