Ellen M. Velie

Periconceptional vitamin use, dietary folate, and the occurrence of neural tube defects.

With a case-control study, we investigated whether periconceptional intake of supplemental or dietary folate reduced the risk of having a neural tube defect (NTD)-affected pregnancy. Mothers of 549 (88% of eligible) cases and 540 (88%) controls were interviewed in person about vitamin supplements used in either the 3 months before or the 3 months after conception and also about usual diet in the 3 months before conception. Women with any use of a folic acid-containing vitamin in the 3 months before conception had a lower risk of having an NTD-affected pregnancy [odds ratio (OR) = 0.65; 95% confidence interval (CI) = 0.45–0.94]. ORs were similar for 3 levels (< 0.4, 0.4–0.9, and >0.9 mg per day) of average daily intake of folic acid. Any level of use in the first 3 months after conception resulted in a lowered risk as well (OR = 0.60; 95% CI = 0.46–0.79). Reduced risks were less marked for Hispanics and were not observed among women who graduated from college. Modest reduced risks were noted among non-vitamin users whose estimated daily dietary intake of folate was more than 0.227 mg. We observed decreasing risk with increasing folate intake from combined dietary sources and vitamin supplements. A reduction in NTD risk associated with folate intake is consistent with other studies; however, the reduced risk may be particular to subsets of the population, primarily non-Hispanic women and women whose education does not exceed high school.

Maternal illness, including fever, and medication use as risk factors for neural tube defects

We investigated if selected maternal illnesses or medications used during the periconceptional period increased risk of having neural tube defect (NTD)-affected pregnancies. We used a population-based case-control study of fetuses and liveborn infants with NTDs among 1989-1991 California births. In-person interviews were conducted with mothers of 538 (88% of eligible) NTD cases and 539 (88%) nonmalformed controls, usually within 5 months of delivery. A maternal fever or febrile illness episode in the first trimester was associated with an increased risk for having a NTD-affected pregnancy, odds ratio (OR) = 1.91 (95% confidence interval, 1.35-2.72) for fever and OR = 2.02 (1.20-3.43) for febrile illness. Risk estimates were not substantially altered after adjustment for maternal age, race/ethnicity, education, vitamin use, and body mass index. Other reported illnesses were generally not associated with risks of 1.5 or greater, or were too infrequent to adequately estimate risk. An OR of 1.5 or greater was observed for maternal use of guaifenesin, OR = 2.04 (0.79-5.28), and an OR of 0.5 or less was observed for maternal use of calcium-containing medicines, OR = 0.38 (0.14-1.03). Our findings are consistent with previous reports that suggested elevated NTD risks from maternal fever. We could not discriminate, however, whether the increased risks observed for maternal fever were indicative of a causal relation or due to reporting bias. Our findings suggest that many of the illnesses common to reproductive-aged women and the medications commonly used to treat them during pregnancy, except, perhaps, for those illnesses that are febrile-related, do not appear to substantially contribute to the occurrence of NTDs in the population.

Lifetime Reproductive and Anthropometric Risk Factors for Breast Cancer in Postmenopausal Women

Hormonally-linked adult reproductive and anthropometric risk factors have been well established in the etiology of postmenopausal breast cancer, though early life exposures have been evaluated only more recently. Here, we examine the evidence for associations between lifetime reproductive and anthropometric risk factors for postmenopausal breast cancer. The review finds some evidence for the hypothesis that breast cancer risk is determined by the number of susceptible stem cells, modified by the hormonal environment. The in utero experience of an infant may be associated with postmenopausal breast cancer; preeclampsia may decrease and greater birthweight increase risk, but more evidence is needed. Earlier and more rapid childhood growth appears to increase postmenopausal breast cancer risk and childhood obesity to decrease risk, but very few studies have yet examined these associations. Increased final height and earlier age at menarche are consistently associated with increased risk for postmenopausal breast cancer. Later age at first birth, decreased parity, later menopausal age, use of hormone replacement therapy (especially progestin containing), and increased postmenopausal adiposity are well-established risk factors for postmenopausal breast cancer. The effect of a womans own pregnancy conditions and lactation are not established. Further investigation is needed to identify whether events occurring early in life modify later events or accumulate over the life course. Many aspects of this research can be conducted by examining the influence of early life events on intermediary events without the need for longitudinal data.

Risk for neural tube defect-affected pregnancies among women of Mexican descent and white women in California.

OBJECTIVES This study investigated a previously reported 50% or more increased risk for neural tube defect-affected pregnancies among Latina women compared with White women. METHODS Data were derived from a population-based case-control study of fetuses and live-born infants with neural tube defects in a 1989-through-1991 California birth cohort. Interviews were conducted with mothers of 538 (88% of eligible) infants/fetuses with neural tube defects and mothers of 539 (88%) nonmalformed control infants. RESULTS The risk for a neural tube defect-affected pregnancy was approximately twice as high among women of Mexican descent than among White women (odds ratio = 1.9, 95% confidence interval [CI] = 1.5, 2.8). The odds ratio for Mexico-born Mexican women compared with White women was 2.4 (95% CI = 1.7, 3.2), whereas the risk for US-born women of Mexican and other racial/ethnic descent was not substantially higher than that for Whites. The higher risk among Mexico-born Mexican women was not attributable to differences in numerous studied parental characteristics and exposures. CONCLUSIONS Given that nearly 20% of all California births are to Mexico-born Mexican women, the increased risks observed are relevant to the population burden of neural tube defects.

Pregnancy characteristics and maternal breast cancer risk: a review of the epidemiologic literature.

The short- and long-term effects of pregnancy on breast cancer risk are well documented. Insight into potential biological mechanisms for these associations may be gained by studying breast cancer risk and pregnancy characteristics (e.g., preeclampsia, twining), which may reflect hormone levels during pregnancy. To date, no review has synthesized the published literature for pregnancy characteristics and maternal breast cancer using systematic search methods. We conducted a systematic search to identify all published studies. Using PUBMED (to 31 July 2009), 42 relevant articles were identified. Several studies suggest that multiple births may be associated with a lowered breast cancer risk of about 10–30%, but results were inconsistent across 18 studies. The majority of 13 studies suggest about a 20–30% reduction in risk with preeclampsia and/or gestational hypertension. Six of seven studies reported no association for infant sex and breast cancer risk. Data are sparse and conflicting for other pregnancy characteristics such as gestational age, fetal growth, pregnancy weight gain, gestational diabetes, and placental abnormalities. The most consistent findings in a generally sparse literature are that multiple births and preeclampsia may modestly reduce breast cancer risk. Additional research is needed to elucidate associations between pregnancy characteristics, related hormonal profiles, and breast cancer risk.

Is dietary intake of methionine associated with a reduction in risk for neural tube defect-affected pregnancies?

Results from experimental animals and other laboratory data have suggested a role for methionine, an essential amino acid, in normal closure of the neural tube. We hypothesized that women who had higher dietary intakes of methionine would be at lower risk for neural tube defect (NTD)-affected pregnancies. Data were derived from a population-based case-control study of fetuses and liveborn infants with NTDs among a 1989-1991 California birth cohort. Interviews, which included a 100-item food frequency questionnaire, were conducted with mothers of 424 NTD cases and 440 nonmalformed controls. Risk for having an NTD-affected pregnancy was estimated according to quartiles (established from intakes among control mothers) of average daily maternal dietary intake of methionine in the 3 months before conception. We observed an approximately 30-40% reduction in NTD-affected pregnancies among women whose average daily dietary intake of methionine was above the lowest quartile of intake (> 1,341.86 mg/ day). These reductions in NTD risk were observed for both anencephaly and spina bifida; remained after adjustment for maternal race/ethnicity and education; and were observed irrespective of maternal level of folate intake. Although we were unable to establish whether the observed reductions in NTD risk were attributable to maternal periconceptional methionine intake or to another highly correlated nutrient, these data add to the growing body of evidence that maternal diet plays a role in neural tube closure.

Incidence and survival of desmoplastic melanoma in the United States, 1992–2007

Background: Desmoplastic melanoma (DM) represents a relatively rare malignancy. The aim of this study was to describe the incidence and survival of DM in the United States.

The Measurement of Neighborhood Socioeconomic Characteristics and Black and White Residential Segregation in Metropolitan Detroit: Implications for the Study of Social Disparities in Health

Research has suggested that the pattern of residence (integration or segregation) alone is insufficient to explain health disparities by race. Socioeconomic characteristics of neighborhoods where blacks and whites reside must also be considered to explain health disparities. This article has three aims: (1) to describe the component socioeconomic characteristics of census tracts (neighborhoods) of residence in metropolitan Detroit in 2000 for three indexes of socioeconomic position (SEP); (2) to assess the concordance of the three indexes of SEP of census tracts (neighborhoods) categorized into quintiles based on metropolitan Detroit census data in 2000; and (3) to compare the extent to which black–white residential segregation is revealed by SEP of neighborhoods in metropolitan Detroit. Census data from the U.S. Bureau of the Census (SF3) were used to define three indexes of SEP of neighborhoods, the modified Darden/Kamel Composite Socioeconomic Index, the modified Krieger Composite Deprivation Index, and an index of percentage poverty. Residential segregation was measured using the index of dissimilarity. The three indexes similarly captured variability in neighborhood socioeconomic characteristics. Further, sharp geographic inequality was revealed by race and socioeconomic status in the Detroit metropolitan area. The social and spatial structure created by the indexes will help researchers and policymakers better understand the effects of racial and socioeconomic characteristics as well as racial residential segregation on the complex factors related to social disparities in health by race.

Maternal occupational and hobby chemical exposures as risk factors for neural tube defects

In a case-control study, we investigated whether occupational and nonoccupational (hobbies) chemical exposures to women in the periconceptional period increased their risk for having neural tube defect-affected pregnancies. Women were asked about occupational tasks and hobbies performed during the 3

Energy and Nutrient Intakes and Health Practices of Latinas and White Non-Latinas in the 3 Months Before Pregnancy

OBJECTIVE To describe the health practices and energy and nutrient intakes from diet and supplements of foreign- and US-born Latinas and white non-Latinas in the 3 months before pregnancy. DESIGN A descriptive study in which data were obtained retrospectively from 2 questionnaires: an interviewer-administered questionnaire on the subjects medical, reproductive, family, occupational, and lifestyle history and a subject-administered (and interviewer-assisted) 100-item food frequency questionnaire. SUBJECTS/SETTING A population-based sample of California women (n = 462) who gave birth between 1989 and 1991 to single, live-born infants. One third of women were Latinas, of whom 58.1% were foreign born. STATISTICAL ANALYSES Means, standard deviations, and percentiles were computed for energy and nutrient intakes of the total population and for white non-Latinas; US-born Latinas; and foreign-born Latinas. One-way analysis of variance was used to compare group means. RESULTS Mean and median energy intake in all ethnic groups exceeded 2,000 kcal/day, although less than half of the population consumed 5 servings of fruit and vegetables per day. For iron, half of the women were below the Recommended Dietary Allowance. In contrast to the dietary intake of white non-Latinas and US-born Latinas, foreign-born Latinas had the lowest contribution of fat to total energy intake and the highest dietary intake of carbohydrate, cholesterol, fiber, grain products, protein foods, folate, vitamin C, iron, and zinc. CONCLUSIONS A womans ethnicity, as well as whether her place of birth was within or outside of the United States, may be predictors of her dietary and health practices before pregnancy. Vitamin, mineral, and food supplementation and consumption of cold breakfast cereal may be avenues for improving perinatal micronutrient intake.