No increase in pregnancy-related death for African American women

However, the results show a significant increase in maternal mortality for women who live greater distances from the hospital, according to the study Dr Michael Froelich of University of Alabama at Birmingham (UAB) and colleagues. The findings point to differences in health care access as a possible explanation for racial differences in pregnancy-related death in the United States.

Maternal Death Differs by Distance, Not Race

The study included 77 women who died during pregnancy, childbirth, or the postpartum period (after delivery) at UAB Hospital from 1999 to 2010. The largest hospital in Alabama, UAB Hospital averages about 4,500 deliveries per year. Because the hospital sees roughly equal proportions of African American and Caucasian patients, "the study population is ideal for the study of race as a possible determinant of health care outcomes," the researchers write.

The maternal deaths were matched as closely as possible to 154 women who survived pregnancy and childbirth during the same period. For each woman who died, the researchers performed on in-depth analysis of the cause of death. Race was analyzed as a possible risk factor for pregnancy-related death, along with other potential contributing factors.

"There was insufficient evidence to suggest racial disparity," Dr Froelich and coauthors write. African American women accounted for 57 percent of the maternal death group and 61 percent of surviving women. Although the difference was not significant, before statistical adjustment, the risk of death was actually lower for African American compared to Caucasian women.

However, distance from the hospital differed significantly by race. African American women lived an average of 14 miles from UAB Hospital, compared to 34 miles for Caucasian women. (UAB Hospital is located in the center of Birmingham.) For women who died, average distance to the hospital was 90 miles, compared to only 24 miles for the comparison group.

"Overall, longer distance was associated with more frequent mortality," according to the authors. After adjustment for distance, the relationship between race and mortality was still nonsignificant -- however, the trend was now towards a higher risk of death among African American women. Dr Froelich and colleagues note, "Residential proximity had to be considered to get a better characterization of the odds of death by race."

Findings Point to Differences in Access to Care

Lack of recommended prenatal care was also a risk factor for maternal death. As expected, pregnancies ending in the death of the mother were associated with higher rates of adverse outcomes such as preterm birth, cesarean delivery, and fetal death.

National data have shown sharp increases in the risk of maternal mortality over the past two decades: from 7.4 per 100,000 live births in 1986 to 14.5 in 2005. In 2005, the mortality rate in African American women was more than three times higher among African American versus Caucasian women.

In contrast to these national trends, the new study finds no direct link between race and maternal mortality at UAB Hospital -- but does show a strong effect of distance from the hospital. This suggests that increases in the risk of pregnancy-related death may be related to delays in the decision to seek medical care, as well as delays in accessing recommended prenatal care. "If there are racial differences in these delays, these factors could also explain disparities in maternal mortality," Dr Froelich and colleagues write.

If so, then efforts to identify and prevent delays in transferring very ill women from low-resource, outlying hospitals to referral facilities such as UAB Hospital might help to lower maternal mortality rates. The researchers conclude, "We suggest that the next step towards understanding racial differences in maternal deaths reported in the United States should be directed at the health care delivery outside the tertiary care hospital setting and particularly at eliminating access barriers to health care for all women."