Mortality Rates Up in Pregnant Women

Mortality rates among pregnant and recently pregnant women rose consistently in recent years, but increases were not primarily driven by obstetric complications, researchers found.

While all-cause mortality rates among recently pregnant women increased from 44.4 to 53.9 per 100,000 live births from 2015 to 2019 — for an annual percentage change (APC) of 4.4% — deaths due to pregnancy-specific causes remained stagnant (APC -1.5, 95% CI -10.7 to 7.7, P=0.64), reported Jeffrey Howard, PhD, of the University of Texas at San Antonio, and colleagues.

Death rates from drug or alcohol poisoning rose from 4.3 to 8.8 per 100,000, for an APC of 17.4%, they noted in a JAMA research letter.

The rise in both all-cause mortality and mortality from drug or alcohol poisoning was higher among recently pregnant women than it was in the total population of reproductive-age women, for whom mortality rates did not increase for any cause during the study period.

In addition, mortality rates for homicide increased from 2.0 to 3.9 per 100,000, for an APC of 13.5%, which was not statistically significant (P=0.07).

“The maternal mortality problem has been framed as one of healthcare access and delivery issues,” Howard told MedPage Today, adding that maternal death data have typically focused on complications related to delivery, both during pregnancy and immediately after birth.

“What I think these data suggest is that there’s a much bigger issue around this population of women, that … really extends into a broader set of social issues that need to be addressed,” he added.

Maternal deaths related to pregnancy-specific causes are higher in the U.S. than in most other high-income countries, and have continued to trend upward. The U.S. maternal mortality rate climbed in 2019 — the most recent year that data are available — from 17.4 per 100,000 live births in 2018 to 20.1 per 100,000, according to a CDC report. There are significant racial disparities in maternal death rates in the U.S., with Black people facing an increased risk of mortality.

But data on deaths that are both unrelated to pregnancy and outside of the immediate postpartum period are limited, Howard noted.

In this study, Howard and colleagues aimed to define both pregnancy-related mortality and other causes of mortality among pregnant and recently pregnant people in the U.S., including women who were up to a year post delivery.

They analyzed causes of death and live births from 2015 to 2019, using data from the CDC’s National Center for Health Statistics and the WONDER database. They stratified information by causes of death, which were identified as pregnancy-related, or due to drug or alcohol poisoning, motor vehicle collision, homicide, or suicide. They also compared deaths among pregnant and recently pregnant people versus those in the total U.S. population of reproductive-age women.

In total, 9,532 women who were pregnant or recently pregnant died during the study period. The pregnancy-related mortality rate in 2019 was 27.5 per 100,000 live births, which was not significantly different than the rate of 26.7 in 2015.

Howard and colleagues recognized that this study may be limited by a potential misclassification of cause of death and inaccurate pregnancy checkbox documentation on death certificates. Additionally, recently pregnant women were included in the total population of reproductive-age women, thus the differences between the two groups may be conservative.

While these data did not account for race or ethnicity in pregnancy-related death rates, Howard noted that future analyses will include more information on demographics.

He added that the data underscore a need to alter how researchers and policymakers think about data collection around pregnancy-related deaths. A broader analysis of causes of death, as well as an expanded period of time to define pregnancy-related mortality, may inform prevention measures related to drug and alcohol abuse or violence, he explained.

“My hope is that out of this we can start to understand better the contributors and drivers of these unfortunate outcomes, so we can prevent it,” he said.