Disparities in gestational age-specific fetal mortality rates in the United States, 2009-2013

Although studies have examined overall temporal changes in gestational age-specific fetal mortality rates, there is little information on the current status of racial/ethnic differences. We hypothesize that differences exist between racial/ethnic groups across gestational age and that these differences are not equally distributed.

Using the 2009-2013 data from US fetal death and live birth files for non-Hispanic white (NHW); non-Hispanic black (NHB); Hispanic; and American Indian/Alaska Native (AIAN) women, we conducted analyses to examine fetal mortality rates and estimate adjusted prevalence rate ratios and 95% confidence intervals (CIs).

There were lower risks of fetal mortality among NHB women (aPRR = 0.76; 95% CI = 0.71-0.81) and Hispanic women (aPRR = 0.89; 95% CI = 0.83-0.96) compared with NHWs at 22-23 weeks' gestation. For NHB women, the risk was higher starting at 32-33 weeks (aPRR = 1.11; 95% CI = 1.04-1.18) and continued to increase as gestational age increased. Hispanic and AIAN women had lower risks of fetal mortality compared with NHW women until 38-39 weeks.

Further examination is needed to identify causes of fetal death within the later pregnancy period and how those causes and their antecedents might differ by race and ethnicity.