Racial disparities in outcomes of military and civilian births in California.

OBJECTIVE: To examine racial disparities in prenatal care utilization, birth weight, and fetal and neonatal mortality in a population for whom financial barriers to health care services are minimal. STUDY-DESIGN: Using linked birth, fetal death, and infant death certificate files, we examined prenatal care utilization, birth weight distribution, and fetal and neonatal mortality rates for all white and black births occurring in military hospitals in California from January 1, 1981, to December 31, 1985. These patterns were compared with the experience of their civilian counterparts during the same time period. RESULTS: Black mothers had higher percentages of births occurring in teenaged and unmarried mothers than did white mothers in military and civilian populations. First-trimester prenatal care initiation was lower for blacks in the military (relative risk, 0.79; 95% confidence interval, 0.75-0.82) and civilian (relative risk, 0.51; 95% confidence interval, 0.50-0.52) populations. However, the scale of the disparity in prenatal care utilization was significantly smaller (P < .001) in the military group. Rates of low birth weight and fetal and neonatal mortality among blacks were elevated in the military and civilian groups. However, the racial disparity in low birth weight was significantly smaller in the military group (P < .01 and P < .001, respectively). CONCLUSIONS: In populations with decreased financial barriers to health care, racial disparities in prenatal care use and low birth weight were reduced. However, the persistence of significant disparities suggests that more comprehensive strategies will be required to ensure equity in birth and neonatal outcome.

Ruminant methane delta(13C/12C) values: relation to atmospheric methane.

The delta(13C/12C)--values of methane produced by fistulated steers, dairy cattle, and wethers, and dairy and beef cattle herds show a bimodal distribution that appears to be correlated with the plant type (C3 or C4, that is, producing either a three- or a four-carbon acid in the first step of photosynthesis) consumed by the animals. These results indicate that cattle and sheep, on a global basis, release methane with an average delta(13C/12C) value of -60 and -63 per mil, respectively. Together they are a source of atmospheric methane whose delta(13C/12C) is similar to published values for marsh gas and cannot explain the 20 per mil higher values for atmospheric methane.