Kathleen Maher Rasmussen

Background: The World Health Organization and the United Nations International Children's Emergency Fund recommend a global strategy for feeding infants and young children for proper nutrition and health. Objective: We evaluated the effects of following current infant feeding recommendations on the growth of infants and young children in rural Bangladesh. Design: The prospective cohort study involved 1343 infants with monthly measurements on infant feeding practices (IFPs) and anthropometry at 17 occasions from birth to 24 mo of age to assess the main outcomes of weight, length, anthropometric indexes, and undernutrition. We created infant feeding scales relative to the infant feeding recommendations and modeled growth trajectories with the use of multilevel models for change. Results: Mean (±SD) birth weight was 2697 ± 401 g; 30% weighed < 2500 g. Mean body weight at 12 and 24 mo was 7.9 ± 1.1 kg and 9.7 ± 1.3 kg, respectively. More appropriate IFPs were associated (P < 0.001) with greater gain in weight and length during infancy. Prior IFPs were also positively associated (P < 0.005) with subsequent growth in weight during infancy. Children who were in the 75th percentile of the infant feeding scales had greater (P < 0.05) attained weight and weight-for-age z scores and lower proportions of underweight compared with children who were in the 25th percentile of these scales. Conclusions: Our results provide strong evidence for the positive effects of following the current infant feeding recommendations on growth of infants and young children. Intervention programs should strive to improve conditions for enhancing current infant feeding recommendations, particularly in low-income countries.

The objective of this review is to evaluate the evidence for a link between maternal obesity and poor lactation performance. In nonhuman species, excess maternal fatness is deleterious for lactation and also for maternal health and survival. These effects occur during pregnancy and as milk production is beginning. They may result in poor growth and survival of the young. In women, there is a negative association between maternal obesity and the initiation as well as the continuation of breastfeeding. This appears to be derived from biological as well as sociocultural factors that are still poorly understood. Excessive gestational weight gain, complications of pregnancy and delivery, and the condition of the infant at birth may also contribute to this association. Given the increasingly high rates of obesity among women of reproductive age worldwide and the importance of breastfeeding for infant health, further study of this association is essential.

High prepregnant BMI is associated with reduced initiation and duration of breast-feeding (BF). To examine how gestational weight gain (GWG) might modify this association, over a 9-y period, we identified all women (n = 2783) who had attempted to breast-feed their newborns. From their medical records, we categorized them by prepregnant BMI [as underweight (29.0 kg/m²)] and GWG [as below, within, or above the amount recommended by the Institute of Medicine]. Women with a normal BMI who gained within these recommendations served as the reference group in regression analyses, which were adjusted for confounding factors. Both normal-weight (P < 0.05) and obese (P < 0.01) women who exceeded the recommended GWG had higher odds of failing to initiate BF (defined as continuing to breast-feed at 4 d postpartum). Underweight (P < 0.05), overweight (P < 0.05), and obese (P < 0.01) women who exceeded the recommendations for GWG as well as obese women who gained within the recommendations (P < 0.01) had a higher risk of early discontinuation of exclusive BF. Only obese women who gained within or exceeded the recommendations (P < 0.01) for GWG had a higher risk of early discontinuation of any BF. Excessive GWG was associated with a measure of failure to initiate and/or sustain BF in all categories of prepregnant BMI. Thus, in addition to conceiving at a healthy weight, gaining the recommended amount of weight during pregnancy is also important for successful BF.

Nutritional Concerns of Women, the second edition of a book first published in 1996 for $30 less, contains 8 new chapters. Like its predecessor, this new edition can claim to fill a unique niche because few other books have addressed this topic at all, much less so directly or comprehensively. This book is part of the CRC Series in Modern Nutrition, which contains >3 dozen additional titles, all edited, alone or with others, by one of this volume's editors, Ira Wolinsky.

Prepregnant overweight and obesity have been associated with failure to initiate and to sustain breastfeeding (BF) among Caucasian women; however, this relationship has not been studied among either Black or Hispanic women. Information extracted from medical records was used to examine the relationship between prepregnant overweight (BMI = 26.1–29.0 kg/m²) and obesity (BMI > 29.0 kg/m²) and the initiation and duration of BF among Black and Hispanic women living in an urban area. Among 587 Hispanic women, those who were obese were more likely than normal-weight women to feed formula and breast milk rather than to feed breast milk alone before discharge [odds ratio (OR): 1.9; 95% CI: 1.2–3.1]. Obese Hispanic women also had higher rates of discontinuation of exclusive BF [relative risk (RR): 1.5; 95% CI: 1.1–2.0]) and higher rates of discontinuation of BF to any extent (RR: 1.5; 95% CI: 1.1–2.1) during the first 6 mo postpartum. Among 640 Black women, prepregnant BMI was neither associated with differences in feeding pattern before discharge nor with differences in rates of discontinuation of exclusive or any BF. We concluded that among healthy women who attempt to breastfeed in the hospital, maternal prepregnant obesity was negatively associated with initiation and duration of BF in Hispanic women. In contrast, prepregnant BMI did not have the same association among Black women who attempted to breastfeed. We speculate that obesity may have a different biological meaning for BF success in Black women than it does in those who are Caucasian or Hispanic.

Objective. The population subgroups with the highest proportion of overweight and obese women often are characterized by the lowest rates of initiation and shortest durations of breastfeeding. We previously documented that these 2 population-level trends may be related. In a population of white women who lived in a rural area, we observed that prepregnant overweight and obesity were associated with failure to initiate and also to sustain lactation. The means by which being overweight or obese negatively affect lactational performance is unknown and likely to be multifactorial in origin, including the simple mechanical difficulties of latching on and proper positioning of the infant. In addition, we have shown that prepregnant body mass index (BMI) is negatively associated with the timing of lactogenesis II, the onset of copious milk secretion. Although the effects of obesity on the prolactin response to infant suckling have never been studied, we postulated that maternal obesity could compromise this important response. We proposed that this might occur because obesity alters the 24-hour spontaneous release of prolactin and also because prolactin secretion is blunted in response to various stimuli among obese subjects. The fall in progesterone concentration that occurs immediately postpartum is the trigger for the onset of copious milk secretion, but maintenance of prolactin and cortisol concentrations is necessary for this trigger to be effective. Adipose tissue concentrates progesterone. We proposed that this additional source of progesterone would lead to consistently higher progesterone concentrations among obese compared with normal-weight women. This, in turn, would lead to a delay in reaching the appropriate concentration to trigger the onset of lactogenesis II. We tested the hypotheses that a reduced prolactin response to suckling and higher-than-normal progesterone concentration in the first week after delivery might be among the means by which maternal overweight could compromise early lactation. Methods. We enrolled 40 mothers of term infants from the same population that we studied previously. We measured serum prolactin and progesterone concentrations by radioimmunoassay before and 30 minutes after the beginning of a suckling episode at 48 hours and 7 days after delivery. We used path analysis to develop a parsimonious multivariate prediction of the prolactin response to suckling at 48 hours and 7 days postpartum. Results. As expected, prolactin values decreased from 48 hours to 7 days postpartum. Women who were overweight or obese (using the Institute of Medicine’s cutoff for women of a BMI >26 kg/m²) before conception had a lower prolactin response to suckling than normal-weight women at 48 hours but not at day 7. In multivariate analyses, overweight/obesity, primiparity, and birth weight were negatively associated with the prolactin response to suckling at 48 hours. After adjustment for confounding by time since delivery and the duration of the nursing episode, only overweight/obesity remained a significant negative predictor of prolactin response to suckling at day 7. Concentrations of progesterone decreased dramatically from 48 hours to 7 days postpartum but did not differ between normal-weight and overweight/obese women at either time. In addition, the decreases in progesterone concentrations from 48 hours to 7 days postpartum did not differ between the prepregnant BMI groups. Conclusion. The unique and important finding from this study is that overweight/obese women had a lower prolactin response to suckling. This would be expected to compromise the ability of overweight/obese women to produce milk and, over time, could lead to premature cessation of lactation. These findings are important because, during our observation period (just before and after lactogenesis II, the time of onset of copious milk secretion), the prolactin response to suckling is more important for milk production than it is later in lactation. We have previously shown that a high proportion of the overweight and obese women in this population who give up on breastfeeding do so at this time. This finding thus provides evidence of a biological basis for this association, and additional study of it is likely to be informative. We postulated that there would be consistently higher progesterone concentrations in the early postpartum period among obese compared with normal-weight women because adipose tissue is an extraplacental source of this hormone. This hypothesis was not supported in this study because there were no significant differences between normal-weight and overweight/obese women in progesterone concentrations at either 48 hours or 7 days postpartum. The values that we observed at these times were similar to those reported by others in the early postpartum period. The findings from this study add plausibility to our observation that initiation, not just duration of breastfeeding, is negatively affected by maternal overweight/obesity. Although women should begin pregnancy at a healthy weight and gain reasonably during gestation, not all will. Pediatricians can help overweight/obese women to succeed at breastfeeding by targeting them for contact with a lactation consultant before discharge from the hospital to be sure that they have received optimal advice on breastfeeding techniques. In addition, early contact with the mother after discharge—by calling her at home to offer her support and counseling for breastfeeding, by scheduling the first pediatric visit earlier than for other patients, or by enlisting the assistance of public health nurses for a home visit if this is possible—would help overweight/obese women to continue to breastfeed. Being overweight or obese is negatively associated with the prolactin response to suckling in the first week postpartum and, thus, may contribute to early lactation failure.

Anemia is extremely common in pregnant women. It is particularly high in areas of the world that also have high rates of low birth weight (LBW). Although conventional wisdom suggests that poor maternal iron status may compromise fetal growth, iron deficiency and anemia have thus far not been included among the prominent causes of intrauterine growth retardation (1). Whether there is a causal link between maternal iron nutriture and birth weight was considered in a meta-analysis (2) and a systematic review (3). Both concluded that the evidence was insufficient to infer that iron supplementation during pregnancy increased birth weight. This conclusion arose in part because the available studies suffered from one or more design problems (3). In the article by Cogswell et al (4) in this issue of the Journal, the relation between iron supplementation during pregnancy and birth weight is addressed with a better design than that used in many of the studies reviewed.