Cheryl A. Lovelady

Early human milk feeding is associated with a lower risk of necrotizing enterocolitis in very low birth weight infants

Background:Necrotizing enterocolitis (NEC) is a frequent cause of mortality and morbidity in very low birth weight (VLBW) infants. Human milk (HM) feeding has been associated with lower risk of NEC. However, mothers of VLBW infants often experience insufficient milk production, resulting in mixed feedings of HM and formula. Moreover, medical complications often limit the volume of feeding they can be given.Objective:To determine if high proportions of (50% or greater) HM enteral feeding within the first 14 days of life are protective against NEC.Method:This was a prospective cohort study of VLBW infants who were grouped according to the HM proportion of enteral feeding in the first 14 days: <50% (low human milk, LHM, n=46) and ⩾50% (high human milk, HHM, n=156). The outcome of interest was development of NEC (Bell stage 2 or 3). Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) and to assess potential confounding due to perinatal risk factors.Result:Two hundred and two infants were studied. Confirmed NEC occurred in 5/46 (10.6%) of the LHM group, as compared with 5/156 (3.2%) of the HHM. Gestational age was the only perinatal factor associated with risk of NEC. After adjustment for gestational age, HHM was associated with a lower risk of NEC ((OR=0.17, 95% CI: 0.04 to 0.68), P=0.01).Conclusion:Enteral feeding containing at least 50% HM in the first 14 days of life was associated with a sixfold decrease in the odds of NEC.

The Effect of Weight Loss in Overweight, Lactating Women on the Growth of Their Infants

BACKGROUND The retention of weight gained during pregnancy may contribute to obesity. Lactation should promote weight loss, but weight loss is highly variable among lactating women. The risks associated with the restriction of energy intake during lactation have not been adequately evaluated. The purpose of this study was to determine whether weight loss by women during lactation affects the growth of their infants. METHODS We randomly assigned 40 breast-feeding women who were overweight (defined as a body-mass index [the weight in kilograms divided by the square of the height in meters] of 25 to 30) at 4 weeks post partum either to restrict their energy intake by 500 kcal per day and to exercise for 45 minutes per day for 4 days per week (the diet-and-exercise group) or to maintain their usual dietary intake and not exercise more than once per week for 10 weeks (the control group). We measured the weight and fat mass of the women and the weight and length of the infants before, during, and at the end of the study period. RESULTS The mean (+/-SD) energy intake decreased by 544+/-471 kcal per day in the diet-and-exercise group. As compared with the control group, the women in the diet-and-exercise group lost more weight (4.8+/-1.7 kg vs. 0.8+/-2.3 kg, P<0.001) and fat mass (4.0+/-2.0 kg vs. 0.3+/-1.8 kg, P<0.001). The gains in weight and length of the infants whose mothers were in the diet-and-exercise group (1925+/-500 g and 7.8+/-2.0 cm, respectively) were not significantly different from those of the infants whose mothers were in the control group (1861+/-576 g and 7.3+/-1.7 cm). CONCLUSIONS Weight loss of approximately 0.5 kg per week between 4 and 14 weeks post partum in overweight women who are exclusively breast-feeding does not affect the growth of their infants.

A Randomized Study of the Effects of Aerobic Exercise by Lactating Women on Breast-Milk Volume and Composition

BACKGROUND The potential risks and benefits of regular exercise during lactation have not been adequately evaluated. We investigated whether regular aerobic exercise had any effects on the volume or composition of breast milk. METHODS Six to eight weeks post partum, 33 sedentary women whose infants were being exclusively breast-fed were randomly assigned to an exercise group (18 women) or a control group (15 women). The exercise program consisted of supervised aerobic exercise (at a level of 60 to 70 percent of the heart-rate reserve) for 45 minutes per day, 5 days per week, for 12 weeks. Energy expenditure, dietary intake, body composition, and the volume and composition of breast milk were assessed at 6 to 8, 12 to 14, and 18 to 20 weeks post partum. Maximal oxygen uptake and the plasma prolactin response to nursing were assessed at 6 to 8 and 18 to 20 weeks. RESULTS The women in the exercise group expended about 400 kcal per day during the exercise sessions but compensated for this energy expenditure with a higher energy intake than that recorded by the control women (mean [+/- SD], intake, 2497 +/- 436 vs. 2168 +/- 328 kcal per day at 18 to 20 weeks; P < 0.05). Maximal oxygen uptake increased by 25 percent in the exercising women but by only 5 percent in the control women (P < 0.001). There were no significant differences between the two groups in maternal body weight or fat loss, the volume or composition of the breast milk, the infant weight gain, or maternal prolactin levels during the 12-week study. CONCLUSIONS In this study, aerobic exercise performed four or five times per week beginning six to eight weeks post partum had no adverse effect on lactation and significantly improved the cardiovascular fitness of the mothers.

Active Mothers Postpartum A Randomized Controlled Weight-Loss Intervention Trial

BACKGROUND Pregnancy may contribute to overweight and obesity. PURPOSE The primary objective of Active Mothers Postpartum was to promote a reduction in BMI through 24-months postpartum via sustainable lifestyle changes. DESIGN Behavioral intervention RCT to enhance postpartum weight loss. SETTING/PARTICIPANTS A total of 450 overweight or obese women, enrolled 6-weeks postpartum, were recruited through obstetrics clinics and community posters in the Durham NC area. INTERVENTION Intervention participants were offered eight healthy-eating classes, ten physical-activity classes, and six telephone-counseling sessions over 9 months. MAIN OUTCOME MEASURES Changes from baseline (6-weeks postpartum) to 1-month post-intervention (12-months postpartum) in: (1) diet (caloric intake, calories from fat, intake of certain foods); (2) physical activity (self-reported physical activity, television time); and (3) weight (collected 2004-2007, analyzed 2007-2008). RESULTS Mean weight loss was 0.90 kg (+/-5.1 kg) in the intervention group and 0.36 kg (+/-4.9 kg) in the control group; this difference was not significant. There were also no significant group differences in improvement of diet or increased physical activity. In secondary analyses, there was a positive bivariate relationship between classes attended and weight loss (p=0.01). CONCLUSIONS There were no significant differences among the arms in diet, physical activity, or weight change. Home-based interventions via mail, telephone, or Internet/e-mail may be more feasible and successful in this population. The postpartum period is an important phase in womens lives with regard to weight retention, but engaging them during this busy period remains a challenge. TRIAL REGISTRATION NCT00212251.

Human Milk Consumption and Full Enteral Feeding Among Infants Who Weigh ≤1250 Grams

OBJECTIVE. Establishing enteral feeding is an important goal in the care of very low birth weight infants. In such infants, receipt of ≥50 mL/kg per day human milk during hospitalization has been associated with shorter time to full enteral feeding. The objective of this study was to determine whether high proportions (≥50%) of human milk during feeding advancement are associated with shorter time to full enteral feeding and improved feeding tolerance. METHODS. This was a prospective cohort study of very low birth weight infants (n = 127) who were grouped into low (<50%; n = 34) and high (≥50%; n = 93) human milk consumption groups according to their human milk proportion of enteral feeding during the time of feeding advancement. The primary outcomes of interest were ages at which 100 and 150 mL/kg per day enteral feedings were achieved. RESULTS. The high human milk group reached 100 mL/kg per day enteral feeding 4.5 days faster than the low human milk group. The high human milk group reached 150 mL/kg per day enteral feeding 5 days faster than the low human milk group. After adjustment for gestational age, gender, and respiratory distress syndrome, times to reach 100 and 150 mL/kg per day were significantly shorter for those in the high human milk group. Infants in the high human milk group had a greater number of stools per day; other indicators of feeding tolerance were not statistically different. CONCLUSION. In infants who weighed ≤1250 g, enteral feeding that contained at least 50% maternal human milk was associated with fewer days to full enteral feedings.

Effects of exercise on plasma lipids and metabolism of lactating women.

To examine the effects of exercise on plasma lipids and metabolism during lactation, sedentary, exclusively breast-feeding women were randomly assigned to an exercise (E) or control (C) group at 6-8 wk postpartum. E subjects performed aerobic exercise 45 min.d-1, 5 d.wk-1, for 12 wk. Resting metabolic rate (RMR), energy expenditure, body composition, and dietary intake were measured at 6-8, 12-14, and 18-20 wk postpartum. Maximum oxygen uptake (VO2max), postprandial insulin, glucose, and thermic response, and plasma lipid levels were measured at 6-8 and 18-20 wk. VO2max increased by 25% vs 5% in the E vs the C group, respectively (P < 0.0001). RMR was similar between groups and did not change over time. Weight and percent body fat declined (P < 0.01) during the study, but there was no difference between E and C groups. Exercise marginally increased high-density lipoprotein cholesterol levels (P < 0.08), but did not affect other lipid concentrations. Insulin response decreased as VO2max increased (P = 0.05). There was no effect of time or group on glucose or thermic response. Exercise improves cardiovascular fitness during lactation, but does not increase the rate of postpartum weight loss.

Effect of breast-feeding on weight retention at 3 and 6 months postpartum: data from the North Carolina WIC Programme

OBJECTIVE Pregnancy-related weight retention can contribute to obesity, and breast-feeding may facilitate postpartum weight loss. We investigated the effect of breast-feeding on postpartum weight retention. DESIGN A retrospective follow-up study of weight retention, compared in women who were fully breast-feeding, combining breast-feeding with formula-feeding (mixed feeding), or formula-feeding at 3 months (n 14 330) or 6 months (n 4922) postpartum, controlling for demographic and weight-related covariates using multiple linear regression. SETTING The North Carolina Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). SUBJECTS Participants in the North Carolina WIC Programme who delivered a baby between 1996 and 2004. RESULTS In covariate-adjusted analyses, there was no association between breast-feeding and weight retention at 3 months postpartum. At 6 months postpartum, as compared to formula-feeders, mean weight retention was 0·84 kg lower in mixed feeders (95 % CI 0·39, 1·29; P = 0·0002) and 1·38 kg lower in full breast-feeders (95 % CI 0·89, 1·87; P ≤ 0·0001). CONCLUSIONS Breast-feeding was inversely associated with weight retention at 6 months postpartum in this large, racially diverse sample of low-income women. Further, full breast-feeding had a larger protective effect than did breast-feeding combined with formula-feeding.

Predictors of Postpartum Weight Change Among Overweight and Obese Women: Results from the Active Mothers Postpartum Study

BACKGROUND The postpartum period may be critical for the development of midlife obesity. Identifying factors associated with postpartum weight change could aid in targeting women for healthy lifestyle interventions. METHODS Data from Active Mothers Postpartum (AMP), a study of overweight and obese postpartum women (n=450), were analyzed to determine the effect of baseline characteristics, breastfeeding, diet, physical activity, and contraception on weight change from 6 weeks to 12, 18, and 24 months postpartum. The repeated measures mixed model was used to test the association of these effects with weight change. RESULTS Although mean weight loss was modest (0.49 kg by 24 months), the range of weight change was striking (+21.5 kg to -24.5 kg, standard deviation [SD] 7.4). Controlling only for baseline weight, weight loss was associated with breastfeeding, hormonal contraception, lower junk food and greater healthy food intake, and greater physical activity. Only junk food intake and physical activity were significant after controlling for all other predictors. CONCLUSIONS Eating less healthy foods and being less physically active put overweight and obese women at risk of gaining more weight after a pregnancy.

An evolving scientific basis for the prevention and treatment of pediatric obesity

The 2013 Pennington Biomedical Research Center’s Scientific Symposium focused on the treatment and management of pediatric obesity and was designed to (i) review recent scientific advances in the prevention, clinical treatment and management of pediatric obesity, (ii) integrate the latest published and unpublished findings and (iii) explore how these advances can be integrated into clinical and public health approaches. The symposium provided an overview of important new advances in the field, which led to several recommendations for incorporating the scientific evidence into practice. The science presented covered a range of topics related to pediatric obesity, including the role of genetic differences, epigenetic events influenced by in utero development, pre-pregnancy maternal obesity status, maternal nutrition and maternal weight gain on developmental programming of adiposity in offspring. Finally, the relative merits of a range of various behavioral approaches targeted at pediatric obesity were covered, together with the specific roles of pharmacotherapy and bariatric surgery in pediatric populations. In summary, pediatric obesity is a very challenging problem that is unprecedented in evolutionary terms; one which has the capacity to negate many of the health benefits that have contributed to the increased longevity observed in the developed world.

Diet quality and weight change among overweight and obese postpartum women enrolled in a behavioral intervention program.

BACKGROUND Postpartum weight retention is a risk factor for long-term weight gain. Encouraging new mothers to consume a healthy diet may result in weight loss. OBJECTIVE To assess predictors of diet quality during the early postpartum period; to determine whether diet quality, energy intake, and lactation status predicted weight change from 5 to 15 months postpartum; and to determine whether an intervention improved diet quality, reduced energy intake, and achieved greater weight loss compared with usual care. DESIGN Randomized clinical trial (KAN-DO: Kids and Adults Now-Defeat Obesity), a family- and home-based, 10-month, behavioral intervention to prevent childhood obesity, with secondary aims to improve diet and physical activity habits of mothers to promote postpartum weight loss. PARTICIPANTS Overweight/obese, postpartum women (n=400), recruited from 14 counties in the Piedmont region of North Carolina. INTERVENTION Eight education kits, each mailed monthly; motivational counseling; and one group class. METHODS Anthropometric measurements and 24-hour dietary recalls collected at baseline (approximately 5 months postpartum) and follow-up (approximately 10 months later). Diet quality was determined using the Healthy Eating Index-2005 (HEI-2005). STATISTICAL ANALYSES Descriptive statistics, χ(2), analysis of variance, bi- and multivariate analyses were used. RESULTS At baseline, mothers consumed a low-quality diet (HEI-2005 score=64.4 ± 11.4). Breastfeeding and income were positive, significant predictors of diet quality, whereas body mass index was a negative predictor. Diet quality did not predict weight change. However, total energy intake, not working outside of the home, and breastfeeding duration/intensity were negative predictors of weight loss. There were no significant differences in changes in diet quality, decreases in energy intake, or weight loss between the intervention (2.3 ± 5.4 kg) and control (1.5 ± 4.7 kg) arms. CONCLUSIONS The family-based intervention did not promote postpartum weight loss. Reducing energy intake, rather than improving diet quality, should be the focus of weight-loss interventions for overweight/obese postpartum women.