For several weeks a year, the work of nurse-midwife Karen Sheffield-Abdullah is really detective work. She and a team of other medical investigators with the North Carolina public health department scour the hospital records and coroner reports of new moms who died after giving birth.

These maternal mortality review committees look for clues to what contributed to the deaths — unfilled prescriptions, missed postnatal appointments, signs of trouble that doctors overlooked — to figure out how many of them could have been prevented and how.

The committees are at work in almost 40 states in the U.S. and in the latest and largest compilation of such data, released in September by the Centers for Disease Control and Prevention, a staggering 84% of pregnancy-related deaths were deemed preventable.

Even more striking to nurse-detectives like Sheffield-Abdullah, is that 53% of the deaths occurred well after women left the hospital, between seven days and a year after delivery.

"We are so baby focused," she says. "Once the baby is here, it's almost like the mother is discarded. Like a Reese's Peanut Butter Cup. The mom is the wrapper, and the baby is the candy. Once you remove the wrapper, you just discard the wrapper. And what we really need to be thinking about is that fourth trimester, that time after the baby is born."

Mental health conditions were the leading underlying cause of maternal deaths between 2017 and 2019, with white and Hispanic women most likely to die from suicide or drug overdose, while cardiac problems were the leading cause of death for Black women. Both conditions occur disproportionately later in the postpartum period, according to the CDC report.

What it means to focus on the 'fourth trimester'

The data highlights multiple weaknesses in the system of care for new mothers, from obstetricians who are not trained (or paid) to look for signs of mental trouble or addiction, to policies that strip women of health coverage shortly after they give birth.

The number one problem, as Sheffield-Abdullah sees it, is that the typical six-week postnatal checkup is way too late. In the North Carolina data, new moms who later died often missed this appointment, she says, usually because they had to go back to work or they had other children to care for.

"We really need to stay connected while they're in the hospital," Sheffield-Abdullah says, then make sure patients are referred to the appropriate follow-up care "within one to two weeks after delivery."

Increased screening for postpartum depression and anxiety, starting at the first prenatal visit and continuing throughout the year after birth, is another CDC recommendation, as is better coordination of care between medical and social services, says David Goodman, who leads the maternal mortality prevention team at the CDC's Division of Reproductive Health, which issued the report.

A common crisis point in the months after childbirth is when a parent's substance use problem gets so bad that child protective services takes the baby away, precipitating a mother's accidental or intentional overdose. Having access to treatment and making sure child visitations happen regularly could be a key to preventing such deaths, Goodman says.

The most important policy change underscored by the data, he says, has been the expansion of free health coverage through Medicaid. Until recently, pregnancy-related Medicaid coverage typically expired two months postpartum, forcing women to stop taking medications or seeing a therapist or doctor because they couldn't afford the cost out of pocket.

Now, 36 states have either extended or plan to extend Medicaid coverage to a full year postpartum, partly in response to the early work of maternal mortality review committees. For years, the data showed about a third of pregnancy-related deaths occurred one year after delivery, but in this report, they jumped to more than half, Goodman says, putting even more urgency on the importance of longer-term coverage.

"If this is not a call to action, I don't know what is," says Adrienne Griffen, executive director of the Maternal Mental Health Leadership Alliance, a nonprofit focused on national policy. "We've long known that mental health issues are the most common complication of pregnancy and childbirth. We just haven't had the will to do anything about it."

Will abortion rulings threaten maternal mortality further?

The latest CDC study from September analyzed 1,018 deaths in 36 states, almost double the 14 states that participated in the previous report. The CDC is providing even more funding for maternal mortality reviews, Goodman says, with the hope of bringing in more complete data from more states in the future.

Advocates and doctors have been heartened by the increased awareness and attention on maternal mortality, especially the efforts to correct racial disparities: Black women are three times more likely to die from pregnancy-related complications compared to white women.

But many of these same advocates for better maternal care say they are dismayed by the recent U.S. Supreme Court decision eradicating the federal right to abortion; restrictions around reproductive health care, they say, will erode the gains.

Since states like Texas began banning abortions earlier in pregnancy and making fewer exceptions for those cases where the pregnant person's health is endangered, some women are finding it harder to get emergency care for a miscarriage. States are also prohibiting abortions — even in cases of rape or incest — in young girls, who face much higher risk of complications or death from carrying a pregnancy to term.

"More and more women and other birthing individuals are receiving messages that, 'You don't have ownership of your body,'" says Jameta Nicole Barlow, an assistant professor of writing, health policy and management at George Washington University. "Whether it's through policy, whether it's through your doctor who has to adhere to policy, whether it's through your daily work experience, there's this acknowledgment that 'I don't own my body.' "

This will only exacerbate the mental health struggles women experience around pregnancy, Barlow says, especially Black women who are also coping with the long, intergenerational history of slavery and forced pregnancy. She suspects the maternal mortality numbers will get worse before they get better, because of how politics and policy and psychology are intertwined.

"Until we address what's happening politically," she says, "we're not going to help what's happening psychologically."