摘要：Objectives. We examined how changes in risk factors over time influence fetal, first day, and combined fetal–first day mortality and subsequent racial/ethnic disparities. Methods. We selected deliveries to US resident non-Hispanic White and Black mothers from the linked live birth–infant death cohort and fetal deaths files (1995–1996; 2001–2002) and calculated changes over time of mortality rates, odds, and relative odds ratios (RORs) overall and among mothers with modifiable risk factors (smoking, diabetes, or hypertensive disorders). Results. Adjusted odds ratios (AORs) for fetal mortality overall (AOR = 0.99; 95% confidence interval [CI] = 0.96, 1.01) and among Blacks (AOR = 0.98; 95% CI = 0.93, 1.03) indicated no change over time. Among women with modifiable risk factors, the RORs indicated no change in disparities. The ROR was not significant for fetal mortality (ROR = 0.96; 95% CI = 0.83, 1.01) among smokers, but there was evidence of some decline. There was evidence of increase in RORs in fetal death among mothers with diabetes and hypertensive disorders, but differences were not significant. Conclusions. Disparities in fetal, first day, and combined fetal–first day mortality have persisted and reflect discrepancies in care provision or other factors more challenging to measure. Stillbirths (or fetal deaths) have recently received international attention as an unrecognized public health issue. 1 Although much of the focus has been on developing countries, fetal deaths continue to be a concern in developed nations. In the United States, there have been improvements in perinatal (fetal plus infant) mortality over the past few decades, with a 56% decline overall from 1970 (14.0 per 1000 live births plus fetal deaths) to 2005 (6.2 per 1000 live births plus fetal deaths). 2 However, substantial disparities remain and in some cases continue to grow. 3–7 The 2-fold disparities between non-Hispanic Blacks (Blacks) and non-Hispanic Whites (Whites) persist as demonstrated by several studies examining the racial and ethnic disparities in perinatal mortality. 4–9 The primary reason for this widening gap is in part attributable to larger declines in infant and fetal mortality among Whites compared with Blacks. Although many studies have considered temporal changes in perinatal death 5,10 and other studies have considered the influence of selected maternal characteristics and risk factors on adverse birth outcomes, 5,6,8,11 few studies have simultaneously examined these temporal changes in fetal and early infant death in the context of maternal characteristics and risk factors. Our purpose was to examine how temporal changes in maternal, sociodemographic, and medical risk factors influence the changes in fetal, first day, and combined fetal–first day (fetal plus first day death) mortality. We explored racial and ethnic variations and disparities for selected modifiable maternal characteristics and risk factors as related to mortality outcomes, possibly providing some insight into systematic disparities in perinatal health and clinical management. If differences in perinatal or fetal mortality exist between racial and ethnic groups with these potentially modifiable characteristics or behaviors, it is possible that there may be differentials in access to health care or provision of care. We chose to examine first day deaths in combination with fetal deaths because an artificial reduction in fetal deaths may account for a rise in infant deaths. Events once classified as fetal deaths may now be classified as first day deaths reflecting misclassification of the timing of death; changes in management of the delivery of very small, very early fetuses; or overall changes in baseline health.
