A case-control study of 1253 twin pregnancies from a 1982-1987 perinatal data base.

In one regional perinatal network between 1982-1987, 101,506 women delivered infants greater than 500 g, of which 1253 were twin pregnancies (1.2%). This latter group was compared statistically with a 5% random sample of the singletons (N = 5119). The results showed that the women with twin pregnancies were slightly older, had a higher parity, gained more weight during the gestation, and had a heavier body weight at delivery. Twin pregnancies were complicated by increases in hypertension (odds ratio 2.5; 95% confidence interval 2.1-3.1), abruption (odds ratio 3.0; 95% confidence interval 1.9-4.7), and anemia (odds ratio 2.4; 95% confidence interval 1.9-3.0). There was no increased risk of pyelonephritis, placenta previa, or diabetes mellitus in mothers with twins. The twin pregnancies delivered earlier and the infants were smaller, had lower Apgar scores, and were at increased risk for congenital anomalies. Fetal and neonatal mortality rates were significantly increased in the twin infants; the perinatal mortality rates for twin A and twin B were 48.8 and 64.1, respectively, compared with 10.4 per 1000 births for the singleton controls. When the twin infants A and B were of similar weight, they had a similar perinatal mortality (odds ratio 1.0; 95% confidence interval 0.6-1.8). For infants less than 2500 g, twins A and B had lower fetal and neonatal mortality rates than did singletons, but twins heavier than 2500 g were at increased risk of perinatal death.

Is race a risk factor or a risk marker for preterm delivery?

Reasons for the persistent difference in rates of preterm delivery among black and white women are not clear. Known risk factors explain very little of the variance. Recent studies have shown that social class does not fully account for poor pregnancy outcomes among black women. Cultural and environmental factors that vary between the races, but not between the different socioeconomic levels within a race, may account for some of the unexplained ethnic differences in preterm delivery. Any potentially negative exposure that is distributed differentially between racial groups warrants particular attention. The major hypothesis of this research is that US black women are chronically exposed to specific stressors that adversely affect the outcomes of their pregnancies. A psychosocial stress model has been proposed to explain the complex interactions of social, environmental, and medical factors that are unique among women of color. To generate data for the stress model, a research strategy has been designed to identify psychosocial and behavioral risk factors that have a physiologic impact on pregnancy outcome. We propose that race is a marker for this stress but is not in itself a risk factor for preterm delivery.

A public health framework for addressing black and white disparities in preterm delivery.

The Healthy People 2010 objectives call for the elimination of racial disparities in health, along with reductions in several multifactorial perinatal outcomes. Evidence-based interventions have been the focus of discussion to date. We propose a 6-component framework based on knowledge from the social, medical, psychological, and epidemiological literatures to guide development of interventions to reduce preterm delivery and eliminate disparities. Pilot testing and rigorous evaluation of the interventions developed from this framework are encouraged.

Eliminating disparities in perinatal outcomes--lessons learned.

The disparity between blacks and whites in perinatal health ranges from a 2.3-fold excess risk among black women for preterm delivery and infant mortality to a 4-fold excess risk among black women for maternal mortality. To stimulate concerted public health action to address such racial and ethnic disparities in health, the national Healthy People objectives call for elimination of all health disparities by the year 2010. Eliminating health disparities requires a greater understanding of the factors that contribute to their development. This commentary summarizes the state of the science of reducing such disparities and proposes a framework for using the results of qualitative studies on the social context of pregnancy to understand, study, and address disparities in infant mortality and preterm delivery. Understanding the social context of African American women's lives can lead to an improved understanding of the etiology of preterm birth, and can help identify promising new interventions to reduce racial and ethnic disparities in preterm delivery.

Cancer incidence of Hispanics and non-Hispanic whites in Cook County, Illinois.

BACKGROUND: Variations in cancer incidence and mortality rates between Hispanics and non-Hispanic whites have been reported in several regions in the United States. This report describes the ethnic variation in selected cancer sites in Cook County, Illinois. METHODS: Cancer incidence, age-specific, and age-standardized relative rates, and 95% confidence intervals were estimated among Hispanics and non-Hispanic whites in Cook County, Illinois, for 1986-1987. Hispanics were identified using surnames and maiden names with the Generally Useful Ethnic Search System (GUESS). RESULTS: Rates of lung cancer in Hispanics were approximately half of those observed for non-Hispanic whites. Hispanics also had lower rates of colon, breast, and bladder cancer. Hispanic females had rates of invasive cervical cancer that were approximately two times higher than those of non-Hispanic whites. CONCLUSIONS: These results are consistent with previous studies and suggest that Hispanics residing in the United States may retain some of the risk profile of those living in their home country.

An evaluation of the use of dried blood spots from newborn screening for monitoring the prevalence of cocaine use among childbearing women.

A collaborative March of Dimes study was designed to examine the utility of dried blood spot (DBS) materials routinely collected from newborns as a source for monitoring cocaine exposure and to assess the prevalence of cocaine use among childbearing women in Georgia. We used a modified urinary radioimmunoassay (RIA) to anonymously detect the cocaine metabolite benzoylecgonine (BE) in DBSs. Extensive efforts were undertaken to assure absolute nonlinkage of BE data to any individual. The positive results found by RIA were confirmed by a mass spectrometry (MS) method specifically developed to detect BE in DBSs. BE was measured in 23,141 DBSs collected during 2 months of routine newborn screening in Georgia. A good correlation was observed for RIA results versus MS results (r2 = 0.97). The estimated minimal statewide BE prevalence was 4.8 per 1000 childbearing women. We demonstrated that immunoassay testing for cocaine without confirmatory testing can yield falsely elevated prevalence rates. When proper confirmatory testing is done, DBSs are a valuable source for population-based monitoring of substance abuse among childbearing women.