Low birth weight increases the risk of infant mortality, morbidity, and poor development. Maternal nutrition and stress influence birth size, but their combined effect is not known. We hypothesized that an early invitation time to start a prenatal food supplementation program could reduce the negative influence of prenatal maternal stress on birth size, and that effect would differ by infant sex. A cohort of 1041 pregnant women, who had delivered an infant, June 2003-March 2004, was sampled from among 3267 in the randomized controlled trial, Maternal Infant Nutritional Interventions Matlab, conducted in Matlab, Bangladesh. At 8 wk gestation, women were randomly assigned an invitation to start food supplements (2.5 MJ/d; 6 d/wk) either early (~9 wk gestation; early-invitation group) or at usual start time for the governmental program (~20 wk gestation; usual-invitation group). Morning concentration of cortisol was measured from 1 saliva sample/woman at 28-32 wk gestation to assess stress. Birth size measurements for 90% of infants were collected within 4 d of birth. In a general linear model, there was an interaction between invitation time to start the food supplementation program and cortisol with birth weight, length, and head circumference of male infants, but not female infants. Among the usual-invitation group only, male infants whose mothers had higher prenatal cortisol weighed less than those whose mothers had lower prenatal cortisol. Prenatal food supplementation programs that begin first trimester may support greater birth size of male infants despite high maternal stress where low birth weight is a public health concern.

Background: Mexican American females have a higher prevalence of iron deficiency than do non-Hispanic white females. Objective: The objective was to estimate the prevalence of iron deficiency anemia and examine potential reasons for this difference between Mexican American (n = 1194) and non-Hispanic white (n = 1183) females aged 12-39 y. Design: We used data from the third National Health and Nutrition Examination Survey (1988Survey ( -1994. Iron deficiency anemia was defined as abnormal results from ≥ 2 of 3 tests (erythrocyte protoporphyrin, transferrin saturation, and serum ferritin) and a low hemoglobin concentration. We used multiple logistic regression to adjust for factors that were more prevalent in Mexican American females and significantly associated with iron deficiency anemia. Results: The prevalence of iron deficiency anemia was 6.2 ± 0.8% (x -± SE) in Mexican American females and 2.3 ± 0.4% in non-Hispanic white females. Mean dietary iron intake, mean serum vitamin C concentrations, and the proportion of females using oral contraceptives were similar in the 2 groups. Age < 20 y and education were not associated with iron deficiency anemia. After adjustment for poverty level, parity, and iron supplement use, the prevalence of iron deficiency anemia was 2.3 times higher in Mexican American than in nonHispanic white females (95% CI: 1.4, 3.9). In those with a poverty income ratio (based on household income) > 3.0, however, the prevalence of iron deficiency anemia was 2.6 ± 0.9% in Mexican American and 1.9 ± 0.6% in non-Hispanic white females (NS). Conclusion: Although much of the ethnic disparity in iron deficiency anemia remains unexplained, factors associated with household income may be involved.

We used nationally representative data from the third National Health and Nutrition Examination Survey (NHANES III) to examine the relationship between low iron stores (serum ferritin < 12 microg/L) and dietary patterns that might affect iron status among Mexican American (MA) and non-Hispanic white (NHW) girls and women of reproductive age (12-39 y). Dietary data from the qualitative food-frequency questionnaire were used to classify subjects into three categories (using the 25th and 75th quartile values for NHW) for intake of heme iron, nonheme iron, iron absorption enhancers, and iron absorption inhibitors. The prevalence of low iron stores was 17.4% among MA (n = 1368) and 7.9% among NHW (n = 1473). Compared with high intake, the adjusted odds ratio (OR) for low iron stores was 1.80 [95% confidence interval (CI), 1.24-2.62] for medium intake of heme iron and 0.48 (95% CI, 0.25-0.91) for low intake of nonheme iron (plus iron supplement). Compared with no use, use of vitamin C supplements was associated with half the risk of low iron stores (OR = 0.50; 95% CI, 0.29-0.87). Similar results were found after income and parity were controlled for, except that the protective effect of vitamin C supplements was no longer significant. Even after adjustment for sociodemographic and dietary factors, MA women remained at increased risk for low iron stores (OR = 1.80; 95% CI, 1.30-2.49) indicating that the reasons for the higher prevalence of iron deficiency in MA women warrants further investigation.