Association of gestational diabetes and breastfeeding on obesity prevalence in predominately Hispanic low-income youth

Effect of exercise during pregnancy on offspring development through ameliorating high glucose and hypoxia in gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) women require prenatal care to minimize short- and long-term complications. The mechanism by which exercise during pregnancy affects organ development and whether glucose transporter (GLUT) 1 plays a role in GDM offspring organ development remains unknown.

AIM

To determine the effect of exercise during pregnancy on the cardiac, hepatic and renal development of GDM mother’s offspring.

METHODS

Placenta samples were collected from humans and mice. GDM mouse models were created using streptozotocin along with a GDM with exercise group. The hearts, livers and kidneys of 3- and 8-week-old offspring were collected for body composition analysis and staining. The effects of high glucose levels and hypoxia were investigated using HTR8/SVneo. Transwell and wound-healing assays were performed to assess cell migration. Immunofluorescence accompanied with TUNEL and Ki67 staining was used to explore apoptosis and proliferation.

RESULTS

Exercise during pregnancy downregulated the GLUT1 and hypoxia inducible factor-1α expression in placenta from individuals with GDM. Cobalt chloride-induced hypoxia and high glucose levels also significantly decreased migration and apoptosis of HTR8/SVneo cells. In addition, exercise reduced inflammatory cell infiltration in the liver and decreased the tubular vacuolar area in the kidneys of offspring.

CONCLUSION

GDM affects the growth and development of organs in offspring. Exercise during pregnancy can reverse adverse effects of GDM on the development of the heart, liver, and kidney in offspring.

Predictors and risk factors of short-term and long-term outcomes among women with gestational diabetes mellitus (GDM) and their offspring: Moving toward precision prognosis?

As part of the American Diabetes Association Precision Medicine in Diabetes Initiative (PMDI) - a partnership with the European Association for the Study of Diabetes (EASD) - this systematic review is part of a comprehensive evidence evaluation in support of the 2 nd International Consensus Report on Precision Diabetes Medicine. Here, we sought to synthesize evidence from empirical research papers published through September 1 st , 2021 to evaluate and identify prognostic conditions, risk factors, and biomarkers among women and children affected by gestational diabetes mellitus (GDM), focusing on clinical endpoints of cardiovascular disease (CVD) and type 2 diabetes (T2D) among women with a history of GDM; and adiposity and cardiometabolic profile among offspring exposed to GDM in utero. We identified a total of 107 observational studies and 12 randomized controlled trials testing the effect of pharmaceutical and/or lifestyle interventions. Broadly, current literature indicates that greater GDM severity, higher maternal body mass index, belonging to racial/ethnic minority group; and unhealthy lifestyle behaviors would predict a woman's risk of incident T2D and CVD, and an unfavorable cardiometabolic profile among offspring. However, the level of evidence is low (Level 4 according to the Diabetes Canada 2018 Clinical Practice Guidelines for diabetes prognosis) largely because most studies leveraged retrospective data from large registries that are vulnerable to residual confounding and reverse causation bias; and prospective cohort studies that may suffer selection and attrition bias. Moreover, for the offspring outcomes, we identified a relatively small body of literature on prognostic factors indicative of future adiposity and cardiometabolic risk. Future high-quality prospective cohort studies in diverse populations with granular data collection on prognostic factors, clinical and subclinical outcomes, high fidelity of follow-up, and appropriate analytical approaches to deal with structural biases are warranted.

Breastfeeding may benefit cardiometabolic health of children exposed to increased gestational glycemia in utero

PURPOSE

There is altered breastmilk composition among mothers with gestational diabetes and conflicting evidence on whether breastfeeding is beneficial or detrimental to their offspring's cardiometabolic health. We aimed to investigate associations between breastfeeding and offspring's cardiometabolic health across the range of gestational glycemia.

METHODS

We included 827 naturally conceived, term singletons from a prospective mother-child cohort. We measured gestational (26-28 weeks) fasting plasma glucose (FPG) and 2-h plasma glucose (2 hPG) after an oral glucose tolerance test as continuous variables. Participants were classified into 2 breastfeeding categories (high/intermediate vs. low) according to their breastfeeding duration and exclusivity. Main outcome measures included magnetic resonance imaging (MRI)-measured abdominal fat, intramyocellular lipids (IMCL), and liver fat, quantitative magnetic resonance (QMR)-measured body fat mass, blood pressure, blood lipids, and insulin resistance at 6 years old (all continuous variables). We evaluated if gestational glycemia (FPG and 2 hPG) modified the association of breastfeeding with offspring outcomes after adjusting for confounders using a multiple linear regression model that included a 'gestational glycemia × breastfeeding' interaction term.

RESULTS

With increasing gestational FPG, high/intermediate (vs. low) breastfeeding was associated with lower levels of IMCL (p-interaction = 0.047), liver fat (p-interaction = 0.033), and triglycerides (p-interaction = 0.007), after adjusting for confounders. Specifically, at 2 standard deviations above the mean gestational FPG level, high/intermediate (vs. low) breastfeeding was linked to lower adjusted mean IMCL [0.39% of water signal (0.29, 0.50) vs. 0.54% of water signal (0.46, 0.62)], liver fat [0.39% by weight (0.20, 0.58) vs. 0.72% by weight (0.59, 0.85)], and triglycerides [0.62 mmol/L (0.51, 0.72) vs. 0.86 mmol/L (0.75, 0.97)]. 2 hPG did not significantly modify the association between breastfeeding and childhood cardiometabolic risk.

CONCLUSION

Our findings suggest breastfeeding may confer protection against adverse fat partitioning and higher triglyceride concentration among children exposed to increased glycemia in utero.

Association of infant diet with subsequent obesity at 2-5 years among children exposed to gestational diabetes: the SWIFT study

AIMS/HYPOTHESES

This longitudinal analysis evaluated the independent and joint associations of any breastfeeding (BF) or exclusive BF (EBF) and intake of sugar-sweetened beverages (SSBs) and 100% fruit juice from birth to 1 year with subsequent overweight and obesity among young children exposed to gestational diabetes (GDM).

METHODS

The analysis utilised prospectively collected data from participants enrolled in the Study of Women, Infant Feeding and Type 2 Diabetes after GDM (SWIFT); 1035 pregnant women (20-45 years) diagnosed with GDM, of whom 75% were of Black, Hispanic or Asian race and ethnicity. Mother-infant dyad characteristics and infant dietary intake were assessed via research protocols at in-person examinations, telephone interviews and monthly mailed surveys from birth to 1 year. Child weight, length and height were obtained from electronic health records at birth (2008-2011) and ages 2-5 years (2010-2016) to classify BMI percentile groups (n = 835).

RESULTS

Adequate BF (≥6 months), adequate EBF duration (≥6 months), and SSB and 100% fruit juice intake in the first year were independently associated with child obesity at ages 2-5 years (all p < 0.05). Compared with children with adequate EBF and no intake of SSB or 100% fruit juice, those with adequate EBF and intake of 100% fruit juice and/or SSBs had a four- to fivefold higher odds of obesity (aOR 4.2, 95% CI:1.6, 11.2 for 100% fruit juice; aOR 4.5, 95% CI:1.4, 8.5 for fruit juice or SSBs; and aOR 4.7, 95% CI:1.4, 15 for SSBs; all p < 0.01), while those with inadequate EBF (<6 months) and intake of 100% fruit juice and/or SSBs had a six- to 12-fold higher odds of obesity (aOR 6.4, 95% CI:2.4, 17.2 for fruit juice; aOR 6.6, 95% CI:2.7, 14.8 for fruit juice or SSBs; and aOR 12.2, 95% CI:4.3, 25 for SSBs; all p < 0.001). Compared with children with adequate BF and no intake of SSB or 100% fruit juice, those with adequate BF and intake of 100% fruit juice and/or SSBs had a threefold higher odds of obesity (aOR 3.1, 95% CI:1.1, 7.3 for fruit juice; aOR 3.3, 95% CI:1.3, 8.3 for fruit juice or SSBs; and aOR 3.4, 95% CI:1.3, 8.5 for SSBs; all p < 0.05), while those with inadequate BF (<6 months) and intake of 100% fruit juice and/or SSB were associated with five- to tenfold higher odds of obesity (aOR 4.8, 95% CI:2.3, 12.2 for fruit juice; aOR 6.0, 95% CI:2.5, 12.8 for fruit juice or SSBs; aOR 9.5, 95% CI:3.7, 15.1 for SSBs; all p < 0.05).

CONCLUSIONS/INTERPRETATION

This is the first study to prospectively evaluate the relation of BF or EBF duration and intake of SSB and 100% fruit juice during the first year of life with subsequent obesity in children exposed to GDM. Adequate BF or EBF combined with avoidance of SSB and 100% fruit juice during early infancy may ameliorate future child obesity in this high-risk population.

Barriers and benefits to breastfeeding with gestational diabetes

Gestational diabetes mellitus (GDM) is a disease of glucose intolerance during pregnancy and is associated with infant macrosomia, infant hypoglycemia, and increased risk of type 2 diabetes development for both mother and infant. Although breastfeeding potentially mitigates metabolic sequelae for both mother and her offspring, women with GDM are more likely to introduce formula and, therefore, are less likely to exclusively breastfeed, and some studies show less initiation and shorter breastfeeding duration as well. Therefore, women with GDM and their infants warrant investigation of methods by which to increase breastfeeding exclusivity and duration. Exploration of the barriers to breastfeeding for women with GDM demonstrate not only biologic complications such as maternal obesity, increased prevalence of cesarean section, and infant hypoglycemia, but also maternal report of less provider support of breastfeeding and reduced breastfeeding self-efficacy. Consequently, interventions designed to optimize breastfeeding outcomes in this high-risk population should not only focus on the biology but also on provider behavior and maternal social factors.

Gestational Diabetes Mellitus Affects Offspring's Epigenome. Is There a Way to Reduce the Negative Consequences?

Gestational diabetes mellitus (GDM) is the most common pregnancy complication worldwide and may result in short-term and long-term consequences for offspring. The present review highlights evidence of epigenetic programming, mostly from human studies, which occurs in offspring exposed to maternal GDM during different stages of development, paying special attention to the differences in sensitivity of offspring to maternal hyperglycemia as a result of sex-related factors. We also aim to answer the following question: If these epigenetic changes are constant throughout the lifetime of the offspring, how do they present phenotypically?

BMI growth trajectory from ages 2 to 6 years and its association with maternal obesity, diabetes during pregnancy, gestational weight gain, and breastfeeding

OBJECTIVE

To identify latent BMI growth trajectories from ages 2 to 6 years and examine their independent associations with maternal prepregnancy obesity or overweight, pre-existing type 1 (T1D) or type 2 diabetes (T2D) or gestational diabetes (GDM) with or without requiring antidiabetic medications during pregnancy, excessive gestational weight gain (EGWG), and breastfeeding ≤ 6 months.

RESEARCH DESIGN AND METHOD

Data included 71 892 children born at Kaiser Permanente Southern California hospitals in 2007 to 2011 with complete information on maternal risk factors. Group-based trajectory modelling was used to identify latent BMI trajectory groups. Logistic regression was used to assess independent associations adjusted for covariates.

RESULTS

Three distinct BMI trajectory groups were identified: Group 1 (59% of the cohort) had stable low BMI, Group 2 (35% of the cohort) had stable median BMI, and Group 3 (6% of the cohort) had high and increasing BMI over time. Relative to Groups 1 and 2 combined, the adjusted odds ratio (OR) (95% CI) of being in Group 3 associated with maternal exposures were 5.6 (5.1-6.2) for prepregnancy obesity, 2.4 (2.2-2.7) for prepregnancy overweight, 2.1 (1.2-3.7) for T1D, 1.6 (1.4-1.8) for T2D, 1.4 (1.3-1.6) for GDM requiring medication treatment, 1.1 (1.0-1.3) for GDM not requiring medication, 1.3 (1.2-1.4) for EGWG, and 1.2 (1.2-1.3) for breastfeeding ≤ 6 months.

CONCLUSION

Child's high and increasing BMI trajectory was strongly associated with maternal prepregnancy obesity and overweight, modestly associated with maternal T1D, T2D, and GDM requiring medication treatment and EGWG, and slightly associated with breastfeeding ≤ 6 months. GDM not requiring medication treatment during pregnancy had little association.

Association of breastfeeding and early exposure to sugar-sweetened beverages with obesity prevalence in offspring born to mothers with and without gestational diabetes mellitus

BACKGROUND

The relationship of gestational diabetes mellitus (GDM), exclusive breastfeeding (EBF), and sugar-sweetened beverages (SSBs) on obesity prevalence in children has rarely been evaluated.

OBJECTIVE

This study examined the association of GDM status, EBF, and SSB with obesity prevalence in children (1-5 y).

METHODS

Data are from the 2014 Los Angeles County WIC Survey, which included 3707 mothers and their children (1-5 y).

RESULTS

Compared with GDM offspring who were not EBF, GDM offspring who were EBF had lower odds of obesity, as did non-GDM offspring who were and were not EBF. Compared with GDM offspring with high-concurrent SSB intake (>3 servings/d) and no EBF, GDM offspring with high SSB intake and EBF did not have lower odds of obesity, whereas those with GDM, low SSB (≤1 serving/d), and EBF had lower odds of obesity. Using non-GDM, EBF, and low SSB as referent, non-GDM offspring who were not EBF, with either high or low SSB, had approximately a fourfold increase in odds of obesity.

CONCLUSIONS

In GDM offspring, EBF is only associated with lower obesity levels if later SSB intake is also low, whereas EBF is protective against obesity in non-GDM offspring regardless of high or low later SSBs intake.

Gestational diabetes exposure and adiposity outcomes in childhood and adolescence: An analysis of effect modification by breastfeeding, diet quality, and physical activity in the EPOCH study

BACKGROUND

Intrauterine exposure to gestational diabetes (GDM) is associated with increased adiposity; however, not all offspring exposed to GDM exhibit excess adiposity.

OBJECTIVES

Examine whether optimal diet and activity behaviours in infancy, childhood, and adolescence modify the association between GDM exposure and adiposity.

METHODS

In 564 offspring (84 exposed to GDM), we assessed breastfeeding (maternal recall), dietary intake (food frequency questionnaire), physical activity (3-day recall), and adiposity (BMI, waist-to-height ratio, visceral and subcutaneous adipose tissue, and subscapular-to-triceps skinfold ratio) at 10.4 (SD, 1.5) and 16.7 (SD, 1.2) years. Optimal behaviours were defined as >6 breastmilk months, Healthy Eating Index score >60, and daily vigorous activity >1 hour. Linear mixed models assessed the association between GDM exposure and adiposity among those with optimal versus suboptimal health behaviours, adjusting for sex, race/ethnicity, age, and pubertal status.

RESULTS

GDM exposure was associated with increased skinfold ratio, visceral and subcutaneous adipose tissue among those with <6 breastmilk months (all Ps < .05), but only associated with increased skinfold ratio among those with >6 breastmilk months (P = .01). GDM exposure was associated with increases in all adiposity measures among those with Healthy Eating Index scores <60 (P < .01), but not those with scores >60 (P > .10). GDM exposure was associated with increased BMI and subcutaneous adipose tissue among those with >1 hour of vigorous activity (P < .05) but not among those with <1 hour of vigorous activity (P > .30).

CONCLUSIONS

The association of GDM exposure with excess adiposity is attenuated in offspring with more optimal diet and activity behaviours in infancy, childhood, and adolescence.

Exposure to heavy metals during pregnancy related to gestational diabetes mellitus in diabetes-free mothers

Evidence is cumulating on the adverse health effects of environmental exposures on health of the fetus and the childbearing mothers. Among mother's conditions, gestational diabetes mellitus has been considered rarely in spite of its importance for both mother and child. We determined the role of maternal exposure to lead (Pb), cadmium (Cd) and manganese (Mn) to gestational diabetes mellitus (GDM) on diagnosed GDM and impaired glucose tolerance (IGT) in diabetes-free mothers from the French EDEN mother-child cohort. 623 pregnant women without pre-existing diabetes were included in the study. GDM and IGT were diagnosed by a gynecologist during consultations after blood analysis. Pb, Cd and Mn were measured in second-trimester blood samples. Associations between ln-transformed concentrations of metals and GDM and IGT respectively were examined using multiple logistic regression analysis adjusted for potential confounders. The prevalences of GDM and IGT were 7.1% and 10.1% respectively. After adjustment for confounders, Cd was statistically related to having had a diagnosis of GDM or IGT (Adjusted Odds-Ratio (AOR): 1.61, 1.05-2.48), and Pb to GDM at borderline significance (AOR: 1.65, 0.82-3.34). Our findings add to the growing evidence supporting the role of maternal exposure to heavy toxic metals that persist longtime in the environment as a risk factor for GDM.

Gestational Diabetes and Breastfeeding Outcomes: A Systematic Review

Studies of gestational diabetes mellitus in relation to breastfeeding are limited, while their findings are inconsistent. This systematic review was conducted to assess the associations between gestational diabetes and breastfeeding outcomes. An initial search of PubMed, Web of Science, and ProQuest identified 518 studies, and after applying the inclusion criteria, 16 studies were finally included in the review. Four studies reported that “exclusive/predominant/full breastfeeding” rates at discharge were lower in mothers with gestational diabetes than in those without gestational diabetes, and 2 studies showed a shorter duration of “exclusive/predominant breastfeeding” in the former than in the latter. However, most studies found no apparent difference in the rate of “breastfeeding initiation”, “any breastfeeding” duration, or “any breastfeeding” in hospital and at discharge between mothers with and without gestational diabetes. In summary, mothers with gestational diabetes were less likely to exclusively breastfeed their infants and may have a shorter breastfeeding duration than other mothers.

Joint Associations of Maternal Gestational Diabetes and Hypertensive Disorders of Pregnancy With Overweight in Offspring

Objectives: Either maternal gestational diabetes mellitus (GDM) or hypertensive disorder of pregnancy (HDP) is associated with an increased risk of obesity in the offspring. However, their joint associations with obesity in offspring remain unclear. We investigated the joint associations of maternal GDM and HDP with childhood overweight in offspring. Methods: We performed a large study in 1967 mother-child pairs. Maternal GDM was diagnosed according to the 1999 World Health Organization (WHO) criteria. HDP was defined as self-reported doctor-diagnosed hypertension or treatment of hypertension (including gestational hypertension, preeclampsia, sever preeclampsia or eclampsia) after 20 weeks of gestation on the questionnaire. Body mass index (BMI) for age Z-score and childhood overweight were evaluated according to WHO growth reference. We used the general linear models to compare children's Z score for BMI and logistic regression models to estimate odds ratios of childhood overweight according to maternal different status of GDM and HDP. Results: Offspring of mothers with both GDM and HDP had a higher BMI for age Z-score (0.63 vs. 0.03, P < 0.001) than children born to normotensive and normoglycemic pregnancy. After adjustment for maternal and children's major confounding factors, joint GDM and HDP were associated with increased odds ratios of offspring's overweight compared with normotensive and normoglycemic pregnancy (2.97, 95% confidence intervals [CIs] 1.65-5.34) and GDM alone (2.06, 95% CIs 1.20-3.54), respectively. After additional adjustment for maternal pre-pregnancy BMI and gestational weight gain, joint maternal GDM, and HDP was still associated with an increased risk of offspring's overweight compared with the maternal normotensive, and normoglycemic group but became to have a borderline increased risk compared with the maternal GDM alone group. Conclusions: Maternal GDM alone or joint GDM and HDP were associated with increased ratios of offspring's overweight.

Breastfeeding and growth during infancy among offspring of mothers with gestational diabetes mellitus: a prospective cohort study

BACKGROUND

Breastfeeding (BF) may protect against obesity and type 2 diabetes mellitus in children exposed to maternal diabetes in utero, but its effects on infant growth among this high-risk group have rarely been evaluated.

OBJECTIVES

The objective of this study was to evaluate BF intensity and duration in relation to infant growth from birth through 12 months among offspring of mothers with gestational diabetes mellitus (GDM).

METHODS

Prospective cohort of 464 GDM mother-infant dyads (28% White, 36% Hispanic, 26% Asian, 8% Black, 2% other). Weight and length measured at birth, 6-9 weeks, 6 months and 12 months. Categorized as intensive BF or formula feeding (FF) groups at 6-9 weeks (study baseline), and intensity from birth through 12 months as Group 1: consistent exclusive/mostly FF, Group 2: transition from BF to FF within 3-9 months and Group 3: consistent exclusive/mostly BF. Multivariable mixed linear regression models estimated adjusted mean (95% confidence interval) change in z-scores; weight-for-length (WLZ), weight-for-age and length-for-age.

RESULTS

Compared with intensive BF at 6-9 weeks, FF showed greater increases in WLZ-scores from 6 to 9 weeks to 6 months [+0.38 (0.13 to 0.62) vs. +0.02 (-0.15 to 0.19); p = 0.02] and birth to 12 months [+1.11 (0.87 to 1.34) vs. +0.53 (0.37 to 0.69); p < 0.001]. For 12-month intensity and duration, Groups 2 and 3 had smaller WLZ-score increases than Group 1 from 6 to 9 weeks to 6 months [-0.05 (-0.27 to 0.18) and +0.07 (-0.19 to 0.23) vs. +0.40 (0.15 to 0.64); p = 0.01 and 0.07], and birth to 12 months [+0.60 (0.39 to 0.82) and +0.59 (0.33 to 0.85) vs. +0.97 (0.75 to 1.19); p < 0.05].

CONCLUSIONS

Among offspring of mothers with GDM, high intensity BF from birth through 1 year is associated with slower infant ponderal growth and lower weight gain.

Pediatric Obesity Algorithm: A Practical Approach to Obesity Diagnosis and Management

Childhood obesity is a growing global health problem. Despite the highest rates of childhood obesity in the United States and other developed countries over the last 30 years, there is still no clear treatment strategy. Practitioners often do not know where to turn to find guidance on managing the nearly one third of their population who present for medical care either with obesity that coexists with other medical problems or because of obesity. The Pediatric Obesity Algorithm is an evidence based roadmap for the diagnosis and management of children with obesity. In this article, we summarize topics from the Pediatric Obesity Algorithm pertaining to pediatric obesity diagnosis, evaluation, and management including assessment, differential diagnosis, review of systems, diagnostic work up, physical exam, age specific management, comorbidities, use of medications and surgery, and medication associated weight gain. Identifying and treating children with obesity as early as possible is important, as is identifying comorbid conditions. Earlier and more comprehensive management through resources such as the Pediatric Obesity Algorithm serve to help guide health care practitioners with a practical and evidence based approach to the diagnosis and management of children with obesity, and provide families with the tools needed for a healthy future.

Projecting the impact of hypothetical early life interventions on adiposity in children living in low-income households

BACKGROUND

It is difficult to evaluate the effectiveness of interventions aimed at reducing early childhood obesity using randomized trials. Objective To illustrate how observational data can be analysed using causal inference methods to estimate the potential impact of behavioural 'interventions' on early childhood adiposity. Methods We used longitudinal data from 1054 children 1-5 years old enrolled in the Special Supplemental Nutrition Program for Women, Infants and Children and followed (WIC) from 2008 to 2010 for a mean duration of 23 months. The data came from a random sample of WIC families living in Los Angeles County in 2008. We used the parametric g-formula to estimate the impact of various hypothetical behavioural interventions. Results Adjusted mean weight-for-height Z score at the end of follow-up was 0.73 (95% CI 0.65, 0.81) under no intervention and 0.63 (95% CI 0.38, 0.87) for all interventions given jointly. Exclusive breastfeeding for 6 months or longer was the most effective intervention [population mean difference = -0.11 (95% CI -0.22, 0.01)]. Other interventions had little or no effect. Conclusions Compared with interventions promoting healthy eating and physical activity behaviours, breastfeeding was more effective in reducing obesity risk in children aged 1-5 years. When carefully applied, causal inference methods may offer viable alternatives to randomized trials in etiologic and evaluation research.

Postnatal Prevention of Childhood Obesity in Offspring Prenatally Exposed to Gestational Diabetes mellitus: Where Are We Now?

Children exposed to gestational diabetes mellitus (GDM) in utero are at high risk of developing many health problems such as obesity. There is an urgent need to find new strategies to prevent obesity development among high-risk populations such as those children. Accordingly, the aim of this review was to summarize current knowledge on the postnatal prevention of childhood obesity in offspring born from mothers with GDM. Specifically, this review addresses the impact of breastfeeding, complementary feeding practices as well as dietary intake and physical activity during childhood on obesity risk of children exposed to GDM in utero. Furthermore, breast milk composition of diabetic mothers and its potential impact on growth is discussed. According to the available literature, breastfeeding may reduce obesity risk in children exposed to GDM in utero but a longer duration seems necessary to achieve its protective effect against obesity. Detailed analysis of breast milk composition of mothers with GDM will be necessary to fully understand the relationship between breastfeeding and obesity in this specific population. This review highlights the need for more studies addressing the impact of complementary feeding practices and lifestyle habits during childhood on obesity risk of children exposed to GDM in utero.

Does breastfeeding duration decrease child obesity? An instrumental variables analysis

BACKGROUND

Many studies have documented that breastfeeding is associated with a significant reduction in child obesity risk. However, a persistent problem in this literature is that unobservable confounders may drive the correlations between breastfeeding behaviors and child weight outcomes.

OBJECTIVE

This study examines the effect of breastfeeding practices on child weight outcomes at age 2.

METHODS

This study relied on population-based data for all births in Oregon in 2009 followed for two years. We used instrumental variables methods to exploit variations in breastfeeding by mothers immediately after delivery and the degree to which hospitals encouraged mothers to breastfeed in order to isolate the effect of breastfeeding practices on child weight outcomes.

RESULTS

We found that for every extra week that the child was breastfed, the likelihood of the child being obese at age 2 declined by 0.82% [95% CI -1.8% to 0.1%]. Likewise, for every extra week that the child was exclusively breastfed, the likelihood of being obese declined by 0.66% [95% CI -1.4 to 0.06%]. While the magnitudes of effects were modest and marginally significant, the results were robust in a variety of specifications.

CONCLUSION

The results suggest that hospital practices that support breastfeeding may influence childhood weight outcomes.