Associations of infant appetitive traits during milk feeding stage with age at introduction to solids and sweet food/beverage intake.

BACKGROUND: Suboptimal feeding behaviors during infancy, such as introducing solids prior to 4 months and providing foods containing added sugars, are associated with increased risk of later obesity. Although focus group studies suggest that infant appetitive traits during milk feeding stage may influence complementary feeding practices, quantitative evidence on this relationship is lacking. METHODS: This study included women who were followed from first trimester to 1-year postpartum. At 6-months postpartum, mothers (n = 217) completed the Baby Eating Behavior Questionnaire which assesses infant appetitive traits during exclusive milk-feeding (food responsiveness, satiety responsiveness, slowness in eating, enjoyment of food and general appetite). Mothers reported infant dietary intake via a food frequency questionnaire (FFQ) administered at 6, 9 and 12 months, from which age at introduction to solids and sweet foods/beverages, and 6- and 12-month sweet food/beverage intake frequency, were calculated. Linear regression analyses examined the relationship of appetitive traits with age at introduction to solids and sweet foods/beverages, and frequency of sweet food/beverage intake, whereas logistic regression examined associations of appetitive traits with odds of introduction to solids prior to 4 months. RESULTS: Greater infant enjoyment of food was associated (B±SE = 0.45 ± 0.18, p = 0.01) with higher age at introduction to solids. Slowness in eating was inversely associated with 12-month sweet food/beverage intake frequency (B±SE = -0.25 ± 0.10, p = 0.01). Other associations of appetitive traits with age at introduction to solids and sweet food/beverage exposure were not statistically significant. CONCLUSIONS: Findings imply that lower infant enjoyment of food and greater speed of eating during the period of exclusive milk-feeding could be associated with suboptimal complementary feeding practices. Understanding how parents respond to infant appetitive traits may be important considerations in efforts to promote appropriate complementary feeding practices during infancy.

Low carbohydrate diets may increase risk of neural tube defects.

BACKGROUND: Folic acid fortification significantly reduced the prevalence of neural tube defects (NTDs) in the United States. The popularity of "low carb" diets raises concern that women who intentionally avoid carbohydrates, thereby consuming fewer fortified foods, may not have adequate dietary intake of folic acid. METHODS: To assess the association between carbohydrate intake and NTDs, we analyzed data from the National Birth Defects Prevention Study from 1,740 mothers of infants, stillbirths, and terminations with anencephaly or spina bifida (cases), and 9,545 mothers of live born infants without a birth defect (controls) conceived between 1998 and 2011. Carbohydrate and folic acid intake before conception were estimated from food frequency questionnaire responses. Restricted carbohydrate intake was defined as ≤5th percentile among controls. Odds ratios were estimated with logistic regression and adjusted for maternal race/ethnicity, education, alcohol use, folic acid supplement use, study center, and caloric intake. RESULTS: Mean dietary intake of folic acid among women with restricted carbohydrate intake was less than half that of other women (p < .01), and women with restricted carbohydrate intake were slightly more likely to have an infant with an NTD (AOR = 1.30, 95% CI: 1.02, 1.67). CONCLUSIONS: This is the first study to examine the association between carbohydrate intake and NTDs among pregnancies conceived postfortification. We found that women with restricted carbohydrate intake were 30% more likely to have an infant with anencephaly or spina bifida. However, more research is needed to understand the pathways by which restricted carbohydrate intake might increase the risk of NTDs.

Antioxidant Consumption is Associated with Decreased Odds of Congenital Limb Deficiencies.

BACKGROUND: Approximately 1 in 2000 infants is born with a limb deficiency in the US. Research has shown that women's periconceptional diet and use of vitamin supplements can affect risk of birth defects. We investigated whether maternal consumption of nutritional antioxidants was associated with occurrence of transverse limb deficiency (TLD) and longitudinal limb deficiencies (LLD). METHODS: We analysed case-control data from mothers and their singleton infants with TLD (n = 566), LLD (n = 339), or no malformation (controls; n = 9384) in the National Birth Defects Prevention Study (1997-2009). Using a modified food frequency, we estimated usual pre-pregnancy antioxidant consumption by total fruit and vegetable consumption (in grams) grouped into tertiles, and cumulative antioxidant score (ranging from 1 to 10) based on consumption of three antioxidants: beta-carotene, lycopene, and lutein. We estimated odds ratios (OR) adjusted for maternal age, race/ethnicity, education, smoking, alcohol use, body mass index, and total energy. RESULTS: Compared to women in the lowest tertile of fruit and vegetable consumption, women in the highest tertile were less likely to have infants with TLD (OR 0.74, 95% CI 0.57, 0.96) or LLD (OR 0.82, 95% CI 0.59, 1.13). Compared to the lowest antioxidant consumption score of 1, those with the highest score of 10 had ORs of 0.68 (95% CI 0.48, 0.95) for TLD and 0.77 (95% CI 0.50, 1.17) for LLD. CONCLUSIONS: Dietary intake of antioxidants was associated with reduced odds of limb deficiencies. These findings add further evidence for women's periconceptional diet reducing occurrence of some birth defects.

A family-based study of gene variants and maternal folate and choline in neuroblastoma: a report from the Children's Oncology Group.

PURPOSE: Neuroblastoma is a childhood cancer of the sympathetic nervous system with embryonic origins. Previous epidemiologic studies suggest maternal vitamin supplementation during pregnancy reduces the risk of neuroblastoma. We hypothesized offspring and maternal genetic variants in folate-related and choline-related genes are associated with neuroblastoma and modify the effects of maternal intake of folate, choline, and folic acid. METHODS: The Neuroblastoma Epidemiology in North America (NENA) study recruited 563 affected children and their parents through the Children's Oncology Group's Childhood Cancer Research Network. We used questionnaires to ascertain pre-pregnancy supplementation and estimate usual maternal dietary intake of folate, choline, and folic acid. We genotyped 955 genetic variants related to folate or choline using DNA extracted from saliva samples and used a log-linear model to estimate both child and maternal risk ratios and stratum-specific risk ratios for gene-environment interactions. RESULTS: Overall, no maternal or offspring genotypic results met criteria for a false discovery rate (FDR) Q-value <0.2. Associations were also null for gene-environment interaction with pre-pregnancy vitamin supplementation, dietary folic acid, and folate. FDR-significant gene-choline interactions were found for offspring SNPs rs10489810 and rs9966612 located in MTHFD1L and TYMS, respectively, with maternal choline dietary intake dichotomized at the first quartile. CONCLUSION: These results suggest that variants related to one-carbon metabolism are not strongly associated with neuroblastoma. Choline-related variants may play a role; however, the functional consequences of the interacting variants are unknown and require independent replication.

Provision of lipid-based nutrient supplements to Honduran children increases their dietary macro- and micronutrient intake without displacing other foods.

Inadequate energy intake and poor diet quality are important causes of chronic child undernutrition. Strategies for improving diet quality using lipid-based nutrient supplements (LNS) are currently being tested in several countries. To date, information on children's dietary intakes during LNS use is available only from Africa. In this study, we collected 24-h dietary recalls at baseline, 3, 6, 9 and 12 months on Honduran children (n = 298) participating in a cluster-randomised trial of LNS. Generalised estimating equations were used to examine differences in number of servings of 12 food groups in the LNS and control arms, and multi-level mixed effects models were used to compare macro- and micronutrient intakes. Models accounted for clustering and adjusted for child's age, season and breastfeeding status. Mean daily servings of 12 food groups did not differ by study arm at baseline and remained similar throughout the study with the exception of groups that were partially or entirely supplied by LNS (nuts and nut butters, fats, and sweets). Baseline intakes of energy, fat, carbohydrates, protein, folate and vitamin A, but not vitamin B12, iron and zinc were lower in the LNS than control arm. The change in all macro- and micronutrients from baseline to each study visit was larger for the LNS arm than the control, except for carbohydrates from baseline to 9 months. These findings indicate that LNS improved the macro- and micronutrient intakes of young non-malnourished Honduran children without replacing other foods in their diet.

Seasonal variation of 25-hydroxyvitamin D among non-Hispanic black and white pregnant women from three US pregnancy cohorts.

BACKGROUND: Vitamin D deficiency during pregnancy has been associated with increased risk of complications and adverse perinatal outcomes. We evaluated seasonal variation of 25-hydroxyvitamin D [25(OH)D] among pregnant women, focusing on patterns and determinants of variation. METHODS: Data came from three cohort studies in the US that included 2583 non-Hispanic Black and White women having prenatal 25(OH)D concentrations determined. Fourier time series and generalised linear models were used to estimate the magnitude of 25(OH)D seasonality. We modelled seasonal variability using a stationary cosinor model to estimate the phase shift, peak-trough difference, and annual mean of 25(OH)D. RESULTS: We observed a peak for 25(OH)D in summer, a nadir in winter, and a phase of 8 months, which resulted from fluctuations in 25(OH)D3 rather than 25(OH)D2. After adjustment for covariates, the annual mean concentrations and estimated peak-trough difference of 25(OH)D among Black women were 19.8 ng/mL [95% confidence interval (CI) 18.9, 20.5] and 5.8 ng/mL [95% CI 4.7, 6.7], and for non-Hispanic White women were 33.0 ng/mL [95% CI 32.6, 33.4] and 7.4 ng/mL [95% CI 6.0, 8.9]. CONCLUSIONS: Non-Hispanic Black women had lower average 25(OH)D concentrations throughout the year and smaller seasonal variation levels than non-Hispanic White women. This study's confirmation of 25(OH)D seasonality over a calendar year has the potential to enhance public health interventions targeted to improve maternal and perinatal outcomes.

Maternal dietary patterns are associated with risk of neural tube and congenital heart defects.

Studying empirically derived dietary patterns is useful in understanding dietary practice. We classified women by their dietary patterns using latent class analysis of 66 foods and studied the association of these patterns with neural tube defects (NTDs) and congenital heart defects (CHDs) in the U.S. National Birth Defects Prevention Study (1997-2005). Logistic regression models used data from 1,047 with an NTD, 6,641 with a CHD, and 6,123 controls that were adjusted for maternal characteristics and tested the effect modification of multivitamin supplement use. Four latent dietary patterns were identified: prudent, Western, low-calorie Western, and Mexican. Among participants who did not use supplements, those in the Mexican, Western, and low-calorie Western classes were significantly more likely (odds ratios of 1.6, 1.5, and 1.4, respectively) to have offspring born with NTDs than were those in the prudent class after adjustment of for dietary folic acid intake. In contrast, among supplement users, there was no difference in the incidence of NTDs between classes. Associations between dietary class and CHD subgroups were not modified by supplement use except for tetralogy of Fallot; among supplement users, those in the Western class were twice as likely (95% confidence interval: 1.4, 2.8) as the prudent class to have offspring with tetralogy of Fallot. Women who adhered to a Western diet were 1.2 (95% confidence interval: 1.03, 1.35) times more likely to have an infant with septal heart defect than were women who adhered to a prudent diet. A prudent dietary pattern, even with folate fortification, may decrease the risk of NTDs and some heart defects.

Neural tube defects and maternal intake of micronutrients related to one-carbon metabolism or antioxidant activity.

BACKGROUND: Maternal nutritional status has been evaluated to clarify its role in development of neural tube defects (NTDs). Maternal folate intake during pregnancy has been closely evaluated for its association with NTDs. The study objective was to examine associations between NTDs and other dietary periconceptional micronutrient intake, particularly nutrients involved in one-carbon metabolism or antioxidant activity. METHODS: Using data from the National Birth Defects Prevention Study, 1997-2005, logistic regression models were used to estimate the relative risk of NTDs based on maternal micronutrient intake. RESULTS: Results were stratified according to folic acid supplement use, race/ethnicity, and maternal body mass index. Analyses included 954 cases (300 with anencephaly, 654 with spina bifida) and 6268 controls. Higher intakes of folate, thiamin, betaine, iron, and vitamin A were associated with decreased risk of anencephaly among some ethnic and clinical groups. In some groups, higher intakes of thiamin, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, and retinol were associated with decreased risk of spina bifida. CONCLUSION: In addition to folic acid, other micronutrients, including thiamin, betaine, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, iron, retinol, and vitamin A, may decrease the risk of NTD occurrence. Birth Defects Research (Part A) 2012. © 2012 Wiley Periodicals, Inc.

Breastfeeding and long-chain polyunsaturated fatty acid intake in the first 4 post-natal months and infant cognitive development: an observational study.

The aim of this study was to examine infant feeding and the long-chain polyunsaturated fatty acid (LCPUFA) concentration of breast milk and formulas in relation to infant development. The prospective Pregnancy, Infection and Nutrition Study (n=358) collected data on breastfeeding, breast milk samples and the formulas fed through 4months post-partum. At 12months of age, infants' development was assessed (Mullen Scales of Early Learning). Linear regression was used to examine development in relation to breastfeeding, breast milk docosahexaenoic acid (DHA) and arachidonic acid (AA) concentration, and DHA and AA concentration from the combination of breast milk and formula. The median breast milk DHA concentration was 0.20% of total fatty acids [interquartile range (IQR)=0.14, 0.34]; median AA concentration was 0.52% (IQR=0.44, 0.63). Upon adjustment for preterm birth, sex, smoking, race and ethnicity and education, breastfeeding exclusivity was unrelated to development. Among infants exclusively breastfed, breast milk LCPUFA concentration was not associated with development (Mullen composite, DHA: adjusted ß=-1.3, 95% confidence interval: -10.3, 7.7). Variables combining DHA and AA concentrations from breast milk and formula, weighted by their contribution to diet, were unassociated with development. We found no evidence of enhanced infant development related to the LCPUFA content of breast milk or formula consumed during the first four post-natal months.

New findings from the Feeding Infants and Toddlers Study 2008.

The purpose of this chapter is to describe the infant feeding practices among infants and toddlers (aged 0-24 months) and to describe food group consumption patterns of these infants and young children (0-48 months) participating in the 2008 Feeding Infants and Toddlers Study (FITS). The FITS 2008 is a cross-sectional survey of a national sample of US children (n = 3,273). Results indicate a longer duration of breastfeeding; however, 17% of infants received cow's milk before the recommended age of one year. Introduction of complementary foods also appears to be delayed until about 4-6 months. There was a decline in consumption of infant cereal after 8 months that may be contributing to iron deficiencies in the 9-11 months age group. Consumption of 100% juice (particularly among infants) and the daily consumption of desserts or candy, sweetened beverages (particularly among 12-to 20-month-olds), and salty snacks is lower than in the 2002 survey. Overall, 10-20 and 30% of children were not consuming any fruit or vegetable, respectively, in a given day. More preschoolers were drinking 2% milk than whole milk, but about one third were still drinking whole milk. Despite some of these positive changes, improvements in young children's diet still are needed.

Periconceptional intake of folic acid and food folate and risks of preterm delivery.

We investigated multiple sources of folate and folic acid to determine whether their periconceptional intakes were associated with preterm delivery. Studied were controls from the National Birth Defects Prevention Study delivered September 1998 to December 2005. Telephone interviews were conducted with 5952 (68% of eligible) mothers. Women were queried about intake of vitamin supplements in the 12 weeks before conception through delivery. A version of the Nurse's Health Study food frequency questionnaire was used to assess food sources. Eight percent of infants ( N = 487) were preterm (<37 weeks). Compared with women who began intake of supplements with folic acid before pregnancy, those who began any time during pregnancy had an ~20% lowered risk of preterm delivery. Lower dietary intakes showed a modest increased risk of preterm delivery: odds ratios were 1.44 (1.01 to 2.04) for lowest quartile intake of folate and 1.27 (0.95 to 1.69) for lowest quartile intake of folic acid compared with the highest. Findings suggest some evidence that folates influenced risks; however, an interpretation of results was also consistent with no association between intake of folates and preterm delivery.

Nutrient intakes of US infants, toddlers, and preschoolers meet or exceed dietary reference intakes.

OBJECTIVES: To assess the usual nutrient intakes of 3,273 US infants, toddlers, and preschoolers, aged 0 to 47 months, surveyed in the Feeding Infants and Toddlers Study (FITS) 2008; and to compare data on the usual nutrient intakes for the two waves of FITS conducted in 2002 and 2008. DESIGN: The FITS 2008 is a cross-sectional survey of a national random sample of US children from birth through age 47 months. Usual nutrient intakes derived from foods, beverages, and supplements were ascertained using a telephone-administered, multiple-pass 24-hour dietary recall. SUBJECTS: Infants aged birth to 5 months (n=382) and 6 to 11 months (n=505), toddlers aged 12 to 23 months (n=925), and preschoolers aged 24 to 47 months (n=1,461) were surveyed. METHODS: All primary caregivers completed one 24-hour dietary recall and a random subsample (n=701) completed a second 24-hour dietary recall. The personal computer version of the Software for Intake Distribution Estimation was used to estimate the 10th, 25th, 50th, 75th, and 90th percentiles, as well as the proportions below and above cutoff values defined by the Dietary Reference Intakes or the 2005 Dietary Guidelines for Americans. RESULTS: Usual nutrient intakes met or exceeded energy and protein requirements with minimal risk of vitamin and mineral deficiencies. The usual intakes of antioxidants, B vitamins, bone-related nutrients, and other micronutrients were adequate relative to the Adequate Intakes or Estimated Average Requirements, except for iron and zinc in a small subset of older infants, and vitamin E and potassium in toddlers and preschoolers. Intakes of synthetic folate, preformed vitamin A, zinc, and sodium exceeded Tolerable Upper Intake Level in a significant proportion of toddlers and preschoolers. Macronutrient distributions were within acceptable macronutrient distribution ranges, except for dietary fat, in some toddlers and preschoolers. Dietary fiber was low in the vast majority of toddlers and preschoolers, and saturated fat intakes exceeded recommendations for the majority of preschoolers. The prevalence of inadequate intakes, excessive intake, and intakes outside the acceptable macronutrient distribution range was similar in FITS 2002 and FITS 2008. CONCLUSIONS: In FITS 2008, usual nutrient intakes were adequate for the majority of US infants, toddlers, and preschoolers, except for a small but important number of infants at risk for inadequate iron and zinc intakes. Diet quality should be improved in the transition from infancy to early childhood, particularly with respect to healthier fats and fiber in the diets of toddlers and preschoolers.

Prenatal nutrition: a practical guide for assessment and counseling.

Adequate nutrition during the periconceptional and prenatal periods is important for healthy pregnancy outcomes. By enhancing maternal nutritional status, health care providers can help pregnant women lower their risk of certain pregnancy complications and decrease their children's risk of adverse birth outcomes and later chronic disease. Use of evidence-based tools and recommendations will assist in the assessment of pregnant women's diets and streamline the counseling session to optimize their nutritional status. This article contains a review of the literature related to nutrition intervention studies during pregnancy that were designed to improve habits or achieve target weight gains and nutrition recommendations specific for the pregnancy state, as well as tools/resources for the health care provider for implementation of these recommendations into their busy practices.

Risk factors for non-syndromic holoprosencephaly in the National Birth Defects Prevention Study.

Holoprosencephaly (HPE) is a complex structural brain anomaly that results from incomplete cleavage of the forebrain. The prevalence of HPE at birth is low, and risk factors have been difficult to identify. Using data from a large multi-state population-based case-control study, we examined risk factors for non-syndromic HPE. Data from maternal telephone interviews were available for 74 infants with HPE and 5871 controls born between 1997 and 2004. Several characteristics and exposures were examined, including pregnancy history, medical history, maternal diet and use of nutritional supplements, medications, tobacco, alcohol, and illegal substances. We used chi(2)-tests and logistic regression (excluding women with pre-existing diabetes) to examine associations with HPE. Except for diet (year before pregnancy) and sexually transmitted infections (STIs) (throughout pregnancy), most exposures were examined for the time period from the month before to the third month of pregnancy. HPE was found to be associated with pre-existing diabetes (chi(2) = 6.0; P = 0.01), aspirin use [adjusted odds ratio (aOR) = 3.4; 95% confidence interval (CI) 1.6-6.9], lower education level (aOR = 2.5; 95%CI 1.1-5.6), and use of assisted reproductive technologies (ART) (crude OR = 4.2; 95%CI 1.3-13.7). Consistent maternal folic acid use appeared to be protective (aOR = 0.4; 95%CI 0.2-1.0), but the association was of borderline statistical significance. While some of these findings support previous observations, other potential risk factors identified warrant further study.

Self-reported vitamin supplementation in early pregnancy and risk of miscarriage.

Miscarriage is a common and poorly understood adverse pregnancy outcome. In this study, the authors sought to evaluate the relation between self-reported use of prenatal vitamins in early pregnancy and the risk of miscarriage. Between 2000 and 2008, 4,752 US women were prospectively enrolled in Right From the Start. Information about vitamin use was obtained from a first-trimester interview. Discrete-time hazard models were used, candidate confounders were assessed, and the following variables were included in the model: study site, maternal age, gravidity, marital status, education, race/ethnicity, smoking, and use of progesterone in early pregnancy. Approximately 95% of participants reported use of vitamins during early pregnancy. A total of 524 women had a miscarriage. In the final adjusted model, any use of vitamins during pregnancy was associated with decreased odds of miscarriage (odds ratio = 0.43, 95% confidence interval: 0.30, 0.60) in comparison with no exposure. These results should be viewed in the context of a potentially preventive biologic mechanism mitigated by possible confounding by healthy behaviors and practices that are also associated with vitamin supplement use during pregnancy.

Neural tube defects and maternal folate intake among pregnancies conceived after folic acid fortification in the United States.

Rates of neural tube defects have decreased since folic acid fortification of the food supply in the United States. The authors' objective was to evaluate the associations between neural tube defects and maternal folic acid intake among pregnancies conceived after fortification. This is a multicenter, case-control study that uses data from the National Birth Defects Prevention Study, 1998-2003. Logistic regression was used to compute crude and adjusted odds ratios between cases and controls assessing maternal periconceptional use of folic acid and intake of dietary folic acid. Among 180 anencephalic cases, 385 spina bifida cases, and 3, 963 controls, 21.1%, 25.2%, and 26.1%, respectively, reported periconceptional use of folic acid supplements. Periconceptional supplement use did not reduce the risk of having a pregnancy affected by a neural tube defect. Maternal intake of dietary folate was not significantly associated with neural tube defects. In this study conducted among pregnancies conceived after mandatory folic acid fortification, the authors found little evidence of an association between neural tube defects and maternal folic acid intake. A possible explanation is that folic acid fortification reduced the occurrence of folic acid-sensitive neural tube defects. Further investigation is warranted to possibly identify women who remain at increased risk of preventable neural tube defects.

Maternal body mass index and lifestyle exposures and the risk of bilateral renal agenesis or hypoplasia: the National Birth Defects Prevention Study.

Increased maternal body mass index, maternal smoking, and alcohol exposure during pregnancy have been inconsistently reported as potential risk factors for renal birth defects. The low incidence of the most severe renal anomaly, bilateral renal agenesis or hypoplasia (RA/H), has limited the ability to study this fatal defect. Using data from the National Birth Defects Prevention Study, a multicenter case-control study, the authors explored potential relations between RA/H and maternal body mass index, smoking, alcohol, and caffeine exposures. Data available for 75 infants with RA/H born between 1997 and 2003 and for randomly selected control infants without known birth defects (n = 868) were assessed by a model adjusted for folic acid use, all four exposures of interest, and study center. Bilateral RA/H was associated with a body mass index of greater than 30 kg/m(2) prior to pregnancy (adjusted odds ratio (aOR) = 1.92, 95% confidence interval (CI): 1.00, 3.67), smoking during the periconceptional period (aOR = 2.09, 95% CI: 1.08, 4.03), and binge drinking during the second month of pregnancy (aOR = 3.64, 95% CI: 1.19, 11.1). These results support the need for further exploration into the potential mechanisms by which such exposures could interfere with early fetal kidney formation resulting in RA/H.

The effects of prophylactic iron given in prenatal supplements on iron status and birth outcomes: a randomized controlled trial.

OBJECTIVE: The hypothesis that daily use of a prenatal supplement with iron from enrollment to third trimester to initially iron-replete, nonanemic pregnant women would reduce third-trimester anemia and improve birth outcomes was tested. STUDY DESIGN: Eight hundred sixty-seven women in Raleigh, North Carolina, who were at < 20 weeks of gestation were enrolled; 429 of these women had hemoglobin levels of > or = 110 g/L and ferritin levels of > or = 40 microg/L and were assigned randomly to receive prenatal supplements with 30 mg of iron as ferrous sulfate (n = 218 women) or 0 mg of iron (n = 211 women) until 26 to 29 weeks of gestation. Intent-to-treat analysis was used for the outcomes of third-trimester iron status, birth weight, preterm birth, and small-for-gestational age. RESULTS: Mean birth weight was higher by 108 g (P = .03), and the incidence of preterm delivery was lower (8% vs 14%; P = .05) in the 30-mg group compared with the control group, respectively. Iron supplementation did not affect the prevalence of small-for-gestational age infants or third-trimester iron status. CONCLUSION: Prophylactic iron supplementation that is begun early in pregnancy among low income women in the United States may have benefits beyond the reduction of iron deficiency anemia during pregnancy.

Correction for errors in measuring adherence to prenatal multivitamin/mineral supplement use among low-income women.

Adherence to prenatal multivitamin/mineral supplement use is often measured by self-reports or pill counts. Although both measures were shown to overestimate adherence, measurement error is rarely considered. In this study, we examined measurement error in adherence to prenatal supplement use among pregnant women and demonstrated a calibration method to adjust for error. In a validation subsample (n=51) from a larger clinical study of supplementation, adherence was assessed by self-reports, pill counts, and a Medication Event Monitoring System (MEMS) bottle cap that recorded the date and time of each opening of the pill bottle. Mean adherence in the validation sample as measured by the MEMS (the gold standard) was 68%; thus, adherence measured by self-report (77%) and pill count (84%) reflected overestimation. The Pearson correlation coefficients of self-reports and pill counts to MEMS were 0.35 and 0.62, respectively. When adherence was defined as taking >or=75% of the pills prescribed, sensitivity and specificity were greater for pill counts (93 and 52%, respectively) than for self-reports (88 and 44%). The regression coefficient for pill count adherence from a linear regression on MEMS adherence was applied to pill counts from a larger sample (n=244). The adjustment significantly lowered the estimate of adherence from 74 to 64% (P<0.001) in this larger sample. In conclusion, our data show that both self-reports and pill counts overestimate adherence and that linear regression in comparison to an external standard such as MEMS can be used to correct for measurement error in adherence.

Pill count adherence to prenatal multivitamin/mineral supplement use among low-income women.

In the United States, the prevalence of third trimester anemia among low-income pregnant women is 29% and has not improved since the 1980s. Although low adherence has been linked to the ineffectiveness of iron supplementation programs, data regarding adherence to supplementation in low-income women are currently lacking. Hence this study was conducted to better understand the factors associated with adherence to the use of iron-containing prenatal multivitamin/mineral supplements among low-income pregnant women. Adherence to supplement use was assessed by pill counts among 244 pregnant women of 867 women who were initially randomized to receive 1 of 3 prenatal supplements. All women received care at a public prenatal clinic. Maternal characteristics associated with adherence were identified using predictive modeling. Women took 74% of supplements as prescribed. Adherence was higher among non-Hispanic white women than among non-Hispanic black women (79% vs. 72%, P