Allostatic load may not be associated with chronic stress in pregnant women, NHANES 1999-2006

PURPOSE

Pregnant women are generally excluded from studies that measure allostatic load (AL) because there is concern that the changing levels of AL-related biomarkers during pregnancy do not reflect a woman's true AL. The goal of this study was to determine whether AL can be measured in a meaningful way during pregnancy.

METHODS

The National Health and Nutrition Examination Survey (NHANES) is a nationally representative, cross-sectional survey of the U.S. civilian population. AL was based on the distributions of 10 biomarkers in pregnant (n = 1138) and nonpregnant (n = 4993) women aged 15 to 44 from NHANES (1999-2006).

RESULTS

The distribution of each AL-related biomarker differed significantly between pregnant and nonpregnant women (P < .01). Among nonpregnant women, high AL findings were consistent with previous studies (e.g., higher AL in women who are black, are older, and who have lower incomes). However, these associations were not seen in pregnant women.

CONCLUSIONS

Our results suggest that the various biomarkers that comprise AL may reflect proximal factors in pregnancy more strongly than they represent exposure to chronic stress over a woman's lifetime. Therefore, our approach to measuring AL may not provide meaningful information about chronic stress in pregnant women without further consideration of pregnancy-related factors.

Comparison of the use of amniocentesis in two countries with different policies for prenatal testing: the case of France and the United States

OBJECTIVE

To compare maternal age- and education-specific use of amniocentesis in France and the United States.

METHODS

We used two nationally representative datasets, National Perinatal Survey of 1998 in France (n = 12 816) and National Center for Health Statistics birth data for 1997 in the United States (n = 3 799 975). Analyses included binomial regression with test of interactions between country, maternal age and education.

RESULTS

Amniocentesis use was more than threefold greater in France than in the United States (Risk Ratio (RR) 3.2, 95% CI, 3.1-3.4). This was true across maternal age and education groups. Differences in use of amniocentesis were greatest, however, for women with lower levels of education and older (>/=38 years) women.

CONCLUSION

Our results suggest greater use and lesser disparities in maternal age- and education-specific use of amniocentesis in France as compared to that in the United States. These differences may be due to several factors, including differences in women's cultural values and preferences. They may also represent barriers to effective access to prenatal testing, particularly for women in lower socioeconomic groups, in the United States.

The National Children's Study of environmental effects on child health and development

Increasing recognition that children may be more susceptible than adults to environmental exposures and that they experience potentially life-long consequences of such exposures has led to widespread support for a large new cohort study in the United States. In this article, we propose a framework for a new cohort study of children, with follow-up beginning before birth and continuing to age 21 years. We also describe the administrative structure that has been built to develop the proposal further. The structure includes a partnership between federal and nonfederal scientists and relies on a collaborative, interdisciplinary research effort of unprecedented scale in medical research. We discuss briefly how the proposed cohort could be used to examine, among many other things, the effect of chemical contaminants in breast milk on children's health and development.

An outbreak of gram-negative bloodstream infections in chronic hemodialysis patients

Six chronic hemodialysis patients acquired bloodstream infections (BSIs) with Klebsiella pneumoniae of the same serotype and similar plasmid profile during an 11-day period. The 6 case-patients were more likely than noncase-patients to have received dialysis during the fourth shift (p < 0.05) and to have their dialyzers reprocessed for reuse after those of the noncase-patients (p = 0.05). Investigation identified a patient during the same shift with an arteriovenous fistula infected with K. pneumoniae. The dialyzer reprocessing technician did not change gloves between contacting patients and their dialyzers in the treatment area and reprocessing the case-patients' dialyzers at the end of the fourth shift. We conclude that the outbreak of BSIs was caused by cross-contamination of the case-patients' dialyzers with bacteria from the gloves of the reprocessing technician and by inadequate dialyzer disinfection. After revised dialyzer reprocessing techniques and glove-changing policies were instituted, no further clusters of BSIs occurred.