Kathleen M. Rasmussen

Is There a Causal Relationship between Iron Deficiency or Iron-Deficiency Anemia and Weight at Birth, Length of Gestation and Perinatal Mortality?

An extensive literature review was conducted to identify whether iron deficiency, iron-deficiency anemia and anemia from any cause are causally related to low birth weight, preterm birth or perinatal mortality. Strong evidence exists for an association between maternal hemoglobin concentration and birth weight as well as between maternal hemoglobin concentration and preterm birth. It was not possible to determine how much of this association is attributable to iron-deficiency anemia in particular. Minimal values for both low birth weight and preterm birth occurred at maternal hemoglobin concentrations below the current cut-off value for anemia during pregnancy (110 g/L) in a number of studies, particularly those in which maternal hemoglobin values were not controlled for the duration of gestation. Supplementation of anemic or nonanemic pregnant women with iron, folic acid or both does not appear to increase either birth weight or the duration of gestation. However, these studies must be interpreted cautiously because most are subject to a bias toward false-negative findings. Thus, although there may be other reasons to offer women supplemental iron during pregnancy, the currently available evidence from studies with designs appropriate to establish a causal relationship is insufficient to support or reject this practice for the specific purposes of raising birth weight or lowering the rate of preterm birth.

Breastfeeding reduces postpartum weight retention

BACKGROUND Weight gained during pregnancy and not lost postpartum may contribute to obesity in women of childbearing age. OBJECTIVE We aimed to determine whether breastfeeding reduces postpartum weight retention (PPWR) in a population among which full breastfeeding is common and breastfeeding duration is long. DESIGN We selected women from the Danish National Birth Cohort who ever breastfed (>98%), and we conducted the interviews at 6 (n = 36 030) and 18 (n = 26 846) mo postpartum. We used regression analyses to investigate whether breastfeeding (scored to account for duration and intensity) reduced PPWR at 6 and 18 mo after adjustment for maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG). RESULTS GWG was positively (P < 0.0001) associated with PPWR at both 6 and 18 mo postpartum. Breastfeeding was negatively associated with PPWR in all women but those in the heaviest category of prepregnancy BMI at 6 (P < 0.0001) and 18 (P < 0.05) mo postpartum. When modeled together with adjustment for possible confounding, these associations were marginally attenuated. We calculated that, if women exclusively breastfed for 6 mo as recommended, PPWR could be eliminated by that time in women with GWG values of approximately 12 kg, and that the possibility of major weight gain (>or=5 kg) could be reduced in all but the heaviest women. CONCLUSION Breastfeeding was associated with lower PPWR in all categories of prepregnancy BMI. These results suggest that, when combined with GWG values of approximately 12 kg, breastfeeding as recommended could eliminate weight retention by 6 mo postpartum in many women.

High prepregnant body mass index is associated with poor lactation outcomes among white, rural women independent of psychosocial and demographic correlates.

To determine whether high prepregnant body mass index (BMI) is associated with later onset of lactogenesis II (LGII) and shorter duration of breastfeeding, we questioned 151 women about their demographic and psychosocial characteristics during pregnancy and about the onset of LGII during days 1 to 5 postpartum. Compared towomen with earlier (< 72 hours) onset of LGII, those with later onset had a higher BMI (P < .05), a higher proportion of primiparity (P < .01), and a lower infant score on the Mother-Baby Assessment (P < .05). Prepregnant BMI (P < .04) and primiparity (P < .005) were each associated with later onset of LGII, but only primiparity remained significant when both factors were considered simultaneously. These results suggest that, in addition to those who have just delivered their first infant, those with higher prepregnant BMI values also warrant extra support to decrease their risk of early discontinuation of breastfeeding. J Hum Lact. 20(1):18-29.

Recommendations for weight gain during pregnancy in the context of the obesity epidemic

The Institute of Medicine and the National Research Council have issued new guidelines for gestational weight gain as well as recommendations for action and research that call for “a radical change in the care provided to women of childbearing age.” For the first time, these guidelines consider the outcomes of both mother and child during and after delivery and the trade-offs between them. The recommendations call for women to begin pregnancy at a healthy weight and to gain within the guidelines, a goal not previously achieved. They also call for individualized preconceptional, prenatal, and postpartum care to help women attain a healthy weight, gain within the guidelines, and return to a healthy weight. Scientific evidence was inadequate to provide specific guidelines by obesity class or to support a public health recommendation to reduce the guidelines below 5-9 kg (11-20 lb) for obese women.

Pregnancy outcomes related to gestational weight gain in women defined by their body mass index, parity, height, and smoking status

BACKGROUND Recommendations for gestational weight gain (GWG) account for a womans prepregnancy body mass index (BMI), but other factors may be important. OBJECTIVES The objectives were to investigate whether, within BMI categories, the GWG with the lowest risks to mother and infant varied with parity and to describe these risks in short (<160 cm), young (<20 y), and smoking women. DESIGN Of 27,030 primiparous and 31,407 multiparous women with term births within the Danish National Birth Cohort, self-reported GWG was divided into 6 categories (<5, 5-9, 10-15, 16-19, 20-24, and > or =25 kg). Population-based registers provided information about birth outcomes. GWG-specific absolute adjusted risks for emergency cesarean delivery, birth of a small-for-gestational-age (SGA) or large-for-gestational-age (LGA) infant, and postpartum (6 mo) weight retention (PPWR) were compared across different types of women. RESULTS The risk of SGA decreased with increasing GWG in both parity groups, but SGA risk <10% was reached at 2-3 GWG categories lower in multiparae than in primiparae. An excess risk of LGA was present only in obese primiparae and multiparae, but the PPWR risk increased with increasing GWG irrespective of BMI and parity. Young primiparae had better outcomes than other primiparae. Short women had a higher risk of emergency cesarean delivery that varied minimally with GWG. Smokers had a higher SGA risk and had a PPWR risk similar to that of nonsmokers. CONCLUSIONS The tradeoff in risk between mother and infant is reached at lower GWG in multiparae than in primiparae; therefore, a lower GWG may be needed among multiparae. Differential guidelines seem unnecessary for short or young women or smokers.

Breastfeeding and health outcomes for the mother-infant dyad.

Worldwide, breastfeeding saves the lives of infants and reduces their disease burden. Breastfeeding also reduces the disease burden for mothers. This article examines who chooses to breastfeed and for how long in the United States. It also reviews the latest evidence about the consequences of breastfeeding for the health of the infant and mother. This review provides support for current national and international recommendations that support breastfeeding.

Household food security is associated with growth of infants and young children in rural Bangladesh.

OBJECTIVE Despite a strong relationship between household food security and the health and nutritional status of adults and older children, the association of household food security with the growth of infants and young children has not been adequately studied, particularly in developing countries. We examined the association between household food security and subsequent growth of infants and young children in rural Bangladesh. DESIGN We followed 1343 children from birth to 24 months of age who were born in the Maternal and Infant Nutrition Intervention in Matlab (MINIMat) study in rural Bangladesh. A food security scale was created from data collected on household food security from the mothers during pregnancy. Data on weight and length were collected monthly in the first year and quarterly in the second year of life. Anthropometric indices were calculated relative to the 2006 WHO child growth standards. Growth trajectories were modelled using multilevel models for change controlling for possible confounders. RESULTS Household food security was associated (P < 0.05) with greater subsequent weight and length gain in this cohort. Attained weight, length and anthropometric indices from birth to 24 months were higher (P < 0.001) among those who were in food-secure households. Proportions of underweight and stunting were significantly (P < 0.05) lower in food-secure households. CONCLUSIONS These results suggest that household food security is a determinant of child growth in rural Bangladesh, and that it may be necessary to ensure food security of these poor rural households to prevent highly prevalent undernutrition in this population and in similar settings elsewhere in the world.

Associations of maternal obesity and psychosocial factors with breastfeeding intention, initiation, and duration

BACKGROUND Psychosocial factors influence breastfeeding outcomes, but little is known about these characteristics and how they influence breastfeeding behavior of obese women, who are a group that experiences poor breastfeeding outcomes. OBJECTIVES Our objectives were to determine whether 1) maternal prepregnancy body mass index (BMI) is associated with social knowledge of, social influence toward, maternal confidence in, and behavioral beliefs about breastfeeding; 2) BMI and these psychosocial factors predict outcomes of intention to breastfeed, ever breastfed, and the duration of breastfeeding; and 3) BMI and psychosocial factors are associated with these breastfeeding outcomes independent of each other. DESIGN Participants (n = 2824) in the Infant Feeding Practices Study II provided data on psychosocial characteristics and breastfeeding outcomes. In this prospective cohort study, data were analyzed by using logistic and proportional hazards regression models. RESULTS Prepregnancy BMI was associated with confidence in (P < 0.0001), social influence toward (P = 0.02), and social knowledge of (P < 0.0001) breastfeeding but not with behavioral beliefs about breastfeeding (P = 0.45). Obese women did not differ from under- and normal-weight women in the intention to breastfeed (P = 0.07) but had lower odds of ever breastfeeding (P = 0.04) and were at greater risk of an earlier cessation of exclusive (P = 0.0009) and any (P = 0.03) breastfeeding. Only the association with exclusive breastfeeding remained significant after controlling for psychosocial factors (P = 0.01). All psychosocial factors were positively associated with each breastfeeding outcome. CONCLUSIONS Despite their intentions to breastfeed, women with high prepregnancy BMI had psychosocial characteristics associated with poor breastfeeding outcomes. However, these characteristics did not fully explain the association between maternal obesity and breastfeeding outcomes.

Environmental Exposure to Metals and Children's Growth to Age 5 Years: A Prospective Cohort Study

In this prospective cohort study, based on 1,505 mother-infant pairs in rural Bangladesh, we evaluated the associations between early-life exposure to arsenic, cadmium, and lead, assessed via concentrations in maternal and child urine, and childrens weights and heights up to age 5 years, during the period 2001–2009. Concurrent and prenatal exposures were evaluated using linear regression analysis, while longitudinal exposure was assessed using mixed-effects linear regression. An inverse association was found between childrens weight and height, age-adjusted z scores, and growth velocity at age 5 years and concurrent exposure to cadmium and arsenic. In the longitudinal analysis, multivariable-adjusted attributable differences in childrens weight at age 5 years were −0.33 kg (95% confidence interval (CI): −0.60, −0.06) for high (≥95th percentile) arsenic exposure and −0.57 kg (95% CI: −0.88, −0.26) for high cadmium exposure, in comparison with children with the lowest exposure (≤5th percentile). Multivariable-adjusted attributable differences in height were −0.50 cm (95% CI: −1.20, 0.21) for high arsenic exposure and −1.6 cm (95% CI: −2.4, −0.77) for high cadmium exposure. The associations were apparent primarily among girls. The negative effects on childrens growth at age 5 years attributable to arsenic and cadmium were of similar magnitude to the difference between girls and boys in terms of weight (−0.67 kg, 95% CI: −0.82, −0.53) and height (−1.3 cm, 95% CI: −1.7, −0.89).

Association of Pica with Anemia and Gastrointestinal Distress among Pregnant Women in Zanzibar, Tanzania

The etiology of pica, the purposive consumption of non-food substances, is not understood, despite its ubiquity among gravidae. We examined correlates of pica in a representative obstetric population (n = 2,368) on Pemba Island, Zanzibar, Tanzania to examine proposed etiologies. Cross-sectional data were collected on socioeconomic characteristics, food intake, geophagy (earth consumption), amylophagy (raw starch consumption), anthropometry, iron status, parasitic burden, and gastrointestinal morbidities. Amylophagy was reported by 36.3%, geophagy by 5.2%, and any pica by 40.1%. There was a strong additive relationship of geophagy and amylophagy with lower hemoglobin (Hb) concentration and iron deficiency anemia. By multivariate logistic regression, any pica was associated with Hb level (odds ratio [OR] = 0.76, 95% confidence interval [CI] = 0.72-0.81), nausea (OR = 1.45, 95% CI = 1.20-1.73), and abdominal pain (OR = 1.22, 95% CI = 1.01-1.48). These striking results indicate that the nature of the relationship between pica, pregnancy, gastrointestinal distress, and iron deficiency anemia merits further investigation.