CDC Releases Updated Maternal Mortality Data

For the first time since 2007, the National Center for Health Statistics (NCHS) issued a report on maternal mortality, which they define as any death that occurs while a woman is pregnant or within 42 days following the termination of the pregnancy. The center also released reports on life expectancy and mortality for 2018.

Although they are sometimes conflated, maternal mortality differs from pregnancy-related death, as the latter is classified as any death that occurs when a woman is pregnant or within 100 days after the pregnancy ends.

Researchers found in 2018, “The maternal mortality rate is 17.4 per 100,000 live births in the United States.”

The NCHS released a total of 3 reports concerning evaluation of pregnancy status checkboxes for identifying maternal mortality, the impact of pregnancy checkboxes and misclassification on maternal mortality trends in the United States, and changes in coding, publication, and data release on US maternal mortality.

According to NCHS’s acting Associate Director for Science, Amy Branum, PhD, the gap in reporting on maternal mortality was due to insufficient and inconsistent record keeping among states. In 2003, a pregnancy checkbox item was included on death certificates to help facilitate identification of maternal deaths. “While some states began implementing a checkbox item…this was not adopted in a uniform way across all of the states,” she said.

“As more states revised their certificates, it became evident that in many records, the checkbox was the only indication of pregnancy on the record. When that happened, any of the causes of death recorded in the written section, which in these cases were not necessarily related to pregnancy, became converted to maternal causes and the record then became coded as a maternal death,” Branum said.

Additional high rates of false positives and false negatives were found in the records. “As state systems diverged, the comparability of data diminished to the point where, in 2007, NCHS suspended the publication of national maternal mortality data,” according to the CDC.

Now that states are using more comparable methods, the NCHS reevaluated maternal death reporting and, using new coding methods, was able to report maternal mortality data more accurately from 2015 to 2018.

Wide racial and ethnic gaps were highlighted by the new coding method. Per 100,000 live births, for non-Hispanic black women, the rate was 37.1 deaths; for non-Hispanic white women, 14.7 deaths; and for Hispanic women, 11.8 deaths.

According to Branum, classification of rates outside of these ethnicities is difficult due to the discrepancies in how race is reported on death certificates.

When it comes to age, women 41 and older had a rate of 81.9 deaths per 100,000. That number shrunk to 16.6 per 100,000 for women aged 25 to 39.

Under new guidelines, maternal mortality rates will be measured for women aged 10 to 44. In the past, the rate was measured up to age 54. However, “That doesn’t mean that for women over 44, they never get coded as a maternal death. It’s just that we rely solely on the cause of death information for those records,” as opposed to marking the checkbox, Branum explained.

She hopes with more accurate measurements of maternal mortality now in place, more robust data will be available in the future.