Effects of an intervention to promote breastfeeding on maternal adiposity and blood pressure at 11.5 y postpartum: results from the Promotion of Breastfeeding Intervention Trial, a cluster-randomized controlled trial

Prospective associations between breast feeding, metabolic health, inflammation and bone density in women with prior gestational diabetes mellitus

INTRODUCTION

The aim of the study is to investigate prospective associations between breastfeeding and metabolic outcomes, inflammation, and bone density in women with prior gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

We prospectively included 171 women with GDM from the MySweetheart trial. Women were followed during pregnancy (from 24 up to 32 weeks' gestational age) up to 1 year postpartum. Outcomes included weight, weight retention, body composition, insulin resistance and secretion indices, C reactive protein (CRP), and bone density. We compared differences in the associations between breastfeeding and health outcomes between women who breast fed <6 months vs ≥6 months. Analyses were adjusted for potential medical and sociodemographic confounders.

RESULTS

Breastfeeding initiation was 94.2% (n=161) and mean breastfeeding duration was 6.6 months. Breastfeeding duration was independently associated with lower weight, weight retention, body fat, visceral adipose tissue, lean mass, CRP, insulin resistance (Homeostatic Model Assessment for Insulin Resistance), and insulin secretion (Homeostatic Model Assessment of β-cell index) at 1 year postpartum (all p≤0.04) after adjusting for confounders. Breastfeeding was associated with higher insulin resistance-adjusted insulin secretion (Insulin Secretion-Sensitivity Index-2) in the unadjusted analyses only. There was no association between breastfeeding duration and bone density. Compared with <6 months, breastfeeding duration ≥6 months was associated with lower weight, weight retention, body fat, fat-free mass as well as lower CRP at 1 year postpartum (all p<0.05) after adjusting for confounders.

CONCLUSIONS

Longer breastfeeding duration among women with prior GDM was associated with lower insulin resistance, weight, weight retention, body fat and inflammation, but not lower bone density at 1 year postpartum. Breastfeeding for ≥6 months after GDM can help to improve cardiometabolic health outcomes 1 year after delivery.

Association of Handgrip Strength and Cardiovascular Disease Risk Among Middle-Aged Postmenopausal Women: An Analysis of the Korea National Health and Nutrition Examination Survey 2014-2019

Purpose

Handgrip strength is an indicator of overall muscle strength and has been associated with an increased risk of cardiovascular disease. Evidence suggests that menopause is a risk factor for cardiovascular disease in women, and muscle strength decreases progressively after menopause. Despite the prognostic importance of the decline in muscle strength and increased cardiovascular disease risk among postmenopausal women, evidence of their association is limited. This study aimed to investigate the relationship between handgrip strength and cardiovascular disease risk among postmenopausal, middle-aged Korean women.

Patients and Methods

Using pooled cohort equations, we calculated the 10-year risk of atherosclerotic cardiovascular disease (ASCVD) among postmenopausal women (N = 2019) aged 50-64 years without cardiovascular disease history from the 2014-2019 Korea National Health and Nutrition Examination Survey. Relative grip strength was defined as measured grip strength divided by body mass index. Logistic regression analysis of a complex sampling design was performed to evaluate the association between relative grip strength and a predicted 10-year ASCVD risk ≥7.5%.

Results

The average handgrip strength was 24.8 kg, and 5.2% of women were considered for sarcopenia (<18 kg). The quartile-stratified relative grip strength was negatively associated with 10-year ASCVD risk (p < 0.001). In the multiple logistic regression analysis, the adjusted odds ratio for the highest relative grip strength quartile was 0.53 (95% confidence interval [CI]: 0.36-0.78), and that of the group who breastfed for more than 12 months was 1.75 (95% CI: 1.36-2.25) for 10-year ASCVD risk.

Conclusion

Increased handgrip strength may be associated with lower cardiovascular disease risk among middle-aged postmenopausal women in Korea. Our findings provide critical evidence regarding the importance of increasing handgrip strength among postmenopausal, middle-aged women to reduce cardiovascular disease risk. Handgrip strength measurement might be a valuable screening tool for cardiovascular disease prevention.

A cross-sectional study of the association between breastfeeding history and overweight/obesity in postmenopausal women

OBJECTIVES

This study endeavors to augment comprehension of the association between breastfeeding and maternal weight within Asian populations.

METHODS

Data were obtained from the comprehensive 2011 research titled "Risk Evaluation of Cancers in Chinese Diabetic Individuals (REACTION): a longitudinal analysis," focusing specifically on postmenopausal women residing in the metropolitan precincts of Guiyang. It presents a cross-sectional study involving 5,987 parous postmenopausal women, aged 60.1 ± 6.9 years, who underwent assessments of body mass index and waist-to-height ratio. The probability of excessive weight or obesity was evaluated in relation to the aggregate duration of breastfeeding, using single-factor and multivariate logistic regression analyses.

RESULTS

Following multiple adjustments for different confounders, the odds ratios (ORs) demonstrated that women who had borne a single child and breastfed for more than 12 months exhibited an increased prevalence of excessive weight (body mass index ≥24 kg/m 2 ) in contrast to those who abstained from breastfeeding (model I: OR, 1.481; 95% confidence interval, 1.124-1.952; P = 0.005; model II: OR, 1.471; 95% confidence interval, 1.113-1.944; P = 0.007). Conversely, among the subset of women who had given birth to two or more children, no noteworthy associations emerged between breastfeeding duration and the propensity for excessive weight or obesity (all models).

CONCLUSION

In the Asian population, the duration of breastfeeding does not appear to be necessarily linked to the prevalence of overweight or obesity in postmenopausal women.

Breastfeeding initiation and duration among people with mild chronic hypertension: a secondary analysis of the Chronic Hypertension and Pregnancy trial

BACKGROUND

Increased duration of breastfeeding improves maternal cardiovascular health and may be especially beneficial in high-risk populations, such as those with chronic hypertension. Others have shown that individuals with hypertension are less likely to breastfeed, and there has been limited research aimed at supporting breastfeeding goals in this population. The impact of perinatal blood pressure control on breastfeeding outcomes among people with chronic hypertension is unknown.

OBJECTIVE

This study aimed to evaluate whether breastfeeding initiation and short-term duration assessed at the postpartum clinic visit differed according to perinatal blood pressure treatment strategy (targeting blood pressure <140/90 mm Hg vs reserving antihypertensive treatment for blood pressure ≥160/105 mm Hg).

STUDY DESIGN

We performed a secondary analysis of the Chronic Hypertension and Pregnancy trial. This was an open-label, multicenter, randomized trial where pregnant participants with mild chronic hypertension were randomized to receive antihypertensive medications with goal blood pressure <140/90 mm Hg (active treatment) or deferred treatment until blood pressure ≥160/105 mm Hg (control). The primary outcome was initiation and duration of breastfeeding, assessed at the postpartum clinic visit. We performed bivariate analyses and log-binomial and cumulative logit regression models, adjusting models for variables that were unbalanced in bivariate analyses. We performed additional analyses to explore the relationship between breastfeeding duration and blood pressure measurements at the postpartum visit.

RESULTS

Of the 2408 participants from the Chronic Hypertension and Pregnancy trial, 1444 (60%) attended the postpartum study visit and provided breastfeeding information. Participants in the active treatment group had different body mass index class distribution and earlier gestational age at enrollment, and (by design) were more often discharged on antihypertensives. Breastfeeding outcomes did not differ significantly by treatment group. In the active and control treatment groups, 563 (77.5%) and 561 (78.1%) initiated breastfeeding, and mean durations of breastfeeding were 6.5±2.3 and 6.3±2.1 weeks, respectively. The probability of ever breastfeeding (adjusted relative risk, 0.99; 95% confidence interval, 0.93-1.05), current breastfeeding at postpartum visit (adjusted relative risk, 1.01; 95% confidence interval, 0.94-1.10), and weeks of breastfeeding (adjusted odds ratio, 0.87; 95% confidence interval, 0.68-1.12) did not differ by treatment group. Increased duration (≥2 vs <2 weeks) of breastfeeding was associated with slightly lower blood pressure measurements at the postpartum visit, but these differences were not significant in adjusted models.

CONCLUSION

In a secondary analysis of the cohort of Chronic Hypertension and Pregnancy trial participants who attended the postpartum study visit and provided breastfeeding information (60% of original trial participants), breastfeeding outcomes did not differ significantly by treatment group. This suggests that maintaining goal blood pressure <140/90 mm Hg throughout the perinatal period is associated with neither harm nor benefit for short-term breastfeeding goals. Further study is needed to understand long-term breastfeeding outcomes among individuals with chronic hypertension and how to support this population in achieving their breastfeeding goals.

Support for healthy breastfeeding mothers with healthy term babies

BACKGROUND

There is extensive evidence of important health risks for infants and mothers related to not breastfeeding. In 2003, the World Health Organization recommended that infants be breastfed exclusively until six months of age, with breastfeeding continuing as an important part of the infant's diet until at least two years of age. However, current breastfeeding rates in many countries do not reflect this recommendation.

OBJECTIVES

1. To describe types of breastfeeding support for healthy breastfeeding mothers with healthy term babies. 2. To examine the effectiveness of different types of breastfeeding support interventions in terms of whether they offered only breastfeeding support or breastfeeding support in combination with a wider maternal and child health intervention ('breastfeeding plus' support).  3. To examine the effectiveness of the following intervention characteristics on breastfeeding support:      a. type of support (e.g. face-to-face, telephone, digital technologies, group or individual support, proactive or reactive);      b. intensity of support (i.e. number of postnatal contacts);      c. person delivering the intervention (e.g. healthcare professional, lay person);     d. to examine whether the impact of support varied between high- and low-and middle-income countries.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (which includes results of searches of CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP)) (11 May 2021) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing extra support for healthy breastfeeding mothers of healthy term babies with usual maternity care. Support could be provided face-to-face, over the phone or via digital technologies. All studies had to meet the trustworthiness criteria.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane Pregnancy and Childbirth methods. Two review authors independently selected trials, extracted data, and assessed risk of bias and study trustworthiness.  The certainty of the evidence was assessed using the GRADE approach.

MAIN RESULTS

This updated review includes 116 trials of which 103 contribute data to the analyses. In total more than 98,816 mother-infant pairs were included.  Moderate-certainty evidence indicated that 'breastfeeding only' support probably reduced the number of women stopping breastfeeding for all primary outcomes: stopping any breastfeeding at six months (Risk Ratio (RR) 0.93, 95% Confidence Interval (CI) 0.89 to 0.97); stopping exclusive breastfeeding at six months (RR 0.90, 95% CI 0.88 to 0.93); stopping any breastfeeding at 4-6 weeks (RR 0.88, 95% CI 0.79 to 0.97); and stopping exclusive breastfeeding at 4-6 (RR 0.83 95% CI 0.76 to 0.90). Similar findings were reported for the secondary breastfeeding outcomes except for any breastfeeding at two months and 12 months when the evidence was uncertain if 'breastfeeding only' support helped reduce the number of women stopping breastfeeding.  The evidence for 'breastfeeding plus' was less consistent. For primary outcomes there was some evidence that 'breastfeeding plus' support probably reduced the number of women stopping any breastfeeding (RR 0.94, 95% CI 0.91 to 0.97, moderate-certainty evidence) or exclusive breastfeeding at six months (RR 0.79, 95% CI 0.70 to 0.90).  'Breastfeeding plus' interventions may have a beneficial effect on reducing the number of women stopping exclusive breastfeeding at 4-6 weeks, but the evidence is very uncertain (RR 0.73, 95% CI 0.57 to 0.95). The evidence suggests that 'breastfeeding plus' support probably results in little to no difference in the number of women stopping any breastfeeding at 4-6 weeks (RR 0.94, 95% CI 0.82 to 1.08, moderate-certainty evidence). For the secondary outcomes, it was uncertain if 'breastfeeding plus' support helped reduce the number of women stopping any or exclusive breastfeeding at any time points.  There were no consistent findings emerging from the narrative synthesis of the non-breastfeeding outcomes (maternal satisfaction with care, maternal satisfaction with feeding method, infant morbidity, and maternal mental health), except for a possible reduction of diarrhoea in intervention infants.  We considered the overall risk of bias of trials included in the review was mixed. Blinding of participants and personnel is not feasible in such interventions and as studies utilised self-report breastfeeding data, there is also a risk of bias in outcome assessment.   We conducted meta-regression to explore substantial heterogeneity for the primary outcomes using the following categories: person providing care; mode of delivery; intensity of support; and income status of country.  It is possible that moderate levels (defined as 4-8 visits) of 'breastfeeding only' support may be associated with a more beneficial effect on exclusive breastfeeding at 4-6 weeks and six months. 'Breastfeeding only' support may also be more effective in reducing women in low- and middle-income countries (LMICs) stopping exclusive breastfeeding at six months compared to women in high-income countries (HICs). However, no other differential effects were found and thus heterogeneity remains largely unexplained. The meta-regression suggested that there were no differential effects regarding person providing support or mode of delivery, however, power was limited.  AUTHORS' CONCLUSIONS: When 'breastfeeding only' support is offered to women, the duration and in particular, the exclusivity of breastfeeding is likely to be increased. Support may also be more effective in reducing the number of women stopping breastfeeding at three to four months compared to later time points.  For 'breastfeeding plus' interventions the evidence is less certain. Support may be offered either by professional or lay/peer supporters, or a combination of both. Support can also be offered face-to-face, via telephone or digital technologies, or a combination and may be more effective when delivered on a schedule of four to eight visits. Further work is needed to identify components of the effective interventions and to deliver interventions on a larger scale.

Exclusive Breastfeeding for at Least Four Months Is Associated with a Lower Prevalence of Overweight and Obesity in Mothers and Their Children after 2-5 Years from Delivery

Introduction: Obesity is a current public health concern. Higher body weight is influenced by genetic and environmental parameters, and their interplay and is associated with a greater risk for several chronic diseases. Breastfeeding has been suggested as a preventive measure against obesity, which can further reduce long-term negative health outcomes for both women and children. Aim: The aim of the present study was to evaluate the role of breastfeeding on maternal and childhood overweight and obesity. Materials and Methods: This is a cross-sectional study conducted on 2515 healthy mothers and their children, aged 2−5 years, enrolled from nine different Greek rural and urban regions. Validated, standardized questionnaires were administrated that included anthropometric indices, socio-demographic characteristics of mothers and children, as well as breastfeeding practices. Results: Overall, 68% of participated women exclusively breastfed their children for at least 4 months. Mothers that exclusively breastfed showed a significantly lower prevalence of overweight and obesity after 2−5 years from delivery (p < 0.0001). Children that had exclusively been breastfed showed a significantly lower prevalence of overweight and obesity at the age of 2−5 years (p < 0.0001). Using multivariate regression analysis, exclusive breastfeeding for at least 4 months was associated with a two-fold lower risk for maternal and childhood overweight and obesity after 2−5 years from delivery, independent from maternal age, educational and economic status, and smoking habits (p < 0.0001). Conclusion: Exclusive breastfeeding for at least 4 months had a positive effect on childhood overweight and obesity, also contributing beneficially to post-natal maternal weight control. The beneficial effects of breastfeeding should be communicated to future and new mothers, while supportive actions for all mothers to initiate and continue breastfeeding their offspring should be implemented.

Effectiveness of breastfeeding education compared to standard hospital information on exclusive breastfeeding among mothers: A systematic review

Breastfeeding is the single intervention with the largest impact on the health of a new-born baby. Evidence has to be generated to convince the mother as well as policy-makers for the promotion of exclusive breastfeeding (EBF) for 6 months. This study aimed to assess the evidence for the effectiveness of breastfeeding education compared with standard hospital information among mothers on the rate of EBF. The study design is systematic review. Trials which are randomized or cluster randomized which studied the effect of educational interventions for mothers on EBF were searched for. Two databases were searched, namely PubMed and Cochrane. Manual search of reference lists of all included studies in Google scholar and Clinical Trial Registry was done. Two reviewers independently assessed the quality of the included studies. Data were extracted using a table format set by the reviewers referring the previously reported high-quality systematic reviews. Out of the 12 comparisons of nine studies included for review, eight studies report that breastfeeding education has added advantage on increasing the rate of EBF. We conclude that there is evidence to support breastfeeding education versus standard hospital information across diverse settings.

Analysis of Maternal Prenatal Weight and Offspring Cognition and Behavior: Results From the Promotion of Breastfeeding Intervention Trial (PROBIT) Cohort

IMPORTANCE

Prenatal experiences can influence fetal brain development.

OBJECTIVE

To examine associations of maternal prenatal body mass index (BMI) with cognition and behavior of offspring born full-term.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined follow-up data from a breastfeeding promotion intervention at 31 hospitals and affiliated polyclinics in the Republic of Belarus. Participants included 11 276 children who were evaluated from birth (1996-1997) to adolescence (2017-2019), with maternal BMI information available in prenatal medical records.

EXPOSURES

Maternal BMI, calculated as weight in kilograms divided by height in meters squared, after 35 weeks gestation; secondary analyses examined maternal BMI at other time points and paternal BMI.

MAIN OUTCOMES AND MEASURES

Trained pediatricians assessed child cognition with the Wechsler Abbreviated Scales of Intelligence (WASI) at 6.5 years and the computerized self-administered NeuroTrax battery at 16 years, both with an approximate mean (SD) of 100 (15). Parents and teachers rated behaviors at 6.5 years using the Strengths and Difficulties Questionnaire (SDQ, range 0-40). Mixed-effects linear regression analyses corrected for clustering, adjusted for the randomized intervention group and baseline parental sociodemographic characteristics, and were considered mediation by child BMI.

RESULTS

Among 11 276 participants, 9355 women (83%) were aged 20 to 34 years, 10 128 (89.8%) were married, and 11 050 (98.0%) did not smoke during pregnancy. Each 5-unit increase in of maternal late-pregnancy BMI (mean [SD], 27.2 [3.8]) was associated with lower offspring WASI performance intelligence quotient (IQ) (-0.52 points; 95% CI, -0.87 to -0.17 points) at 6.5 years and lower scores on 5 of 7 NeuroTrax subscales and the global cognitive score at 16 years (-0.67 points; 95% CI, -1.06 to -0.29 points). Results were similar after adjustment for sociodemographic characteristics, pregnancy complications, and paternal BMI and were not mediated by child weight. Higher late pregnancy maternal BMI was also associated with more behavioral problems reported on the SDQ by teachers but not associated with parent-reported behaviors (externalizing behaviors: 0.13 points; 95% CI, 0.02 to 0.24 points; and total difficulties: 0.14 points, 95% CI, -0.02 to 0.30 points). Results were similar for maternal BMI measured in the first trimester or postpartum. In contrast, higher 6.5-year paternal BMI was associated with slightly better child cognition (WASI verbal IQ: 0.42 points; 95% CI, 0.02 to 0.82 points; NeuroTrax executive function score: 0.68 points; 95% CI, 0.24 to 1.12 points) and fewer teacher-reported behavioral problems (total difficulties: -0.29 points; 95% CI, -0.46 to -0.11 points).

CONCLUSIONS AND RELEVANCE

This cohort study supports findings from animal experiments and human observational studies in settings with higher maternal BMI and obesity rates. Higher maternal prenatal BMI may be associated with poorer offspring brain development, although residual confounding cannot be excluded.

Breastfeeding history and the risk of overweight and obesity in middle-aged women

BACKGROUND

The increased metabolic activity required to sustain breastfeeding and its associated milk production helps to reduce maternal fat stores accumulated during pregnancy. This study aims to assess the association between breastfeeding duration and fatness indices in middle-aged women.

METHODS

The analysis was carried out in a group of 7500 parous 55.5 ± 5.3 year old women included body mass index, body fat percentage, and waist-to-height ratio. The likelihood of excessive weight or obesity in relation to total breastfeeding time using multivariate logistic regression analyses.

RESULTS

An analysis of adjusted odds ratios did not show significant associations between breastfeeding duration and the risk of excessive weight and obesity in premenopausal women. After menopause, women who gave birth to 2 children and breastfed 1-6 and > 12 months had a lower risk of abdominal obesity (OR 0.70; 95% CI 0.50-0.99; p = 0.042; and OR 0.68; 95% CI 0.47-0.98; p = 0.039). Women who gave birth to 3 or more children and breastfed for 1-6 months, also showed a lower risk of overweight (OR 0.52; 95% CI 0.27-0.99; p = 0.047), compared to those ones that have never breastfed. There was no relationship found between the duration of lactation and the risk of excessive body fat.

CONCLUSION

Breastfeeding may have some beneficial, long-term effect on the risk of excessive weight and abdominal obesity in women.

Lifetime duration of lactation and chronic inflammation among middle-aged women with a history of gestational diabetes

INTRODUCTION

Longer duration of lactation is associated with lower cardiometabolic disease risk, but pathogenic pathways involved in the disease progression are unclear, especially among high-risk women. We aimed to examine the associations of lifetime lactation duration with cardiometabolic biomarkers among middle-aged women with a history of gestational diabetes (GDM).

RESEARCH DESIGN AND METHODS

Women with a history of GDM participating in the Nurses' Health Study II, a prospective cohort study, were identified and followed through biennial questionnaires beginning in 1991. Lactation history was asked in three follow-up questionnaires to calculate lifetime duration. In 2012-2014, fasting blood samples were collected through the Diabetes & Women's Health Study to measure inflammatory (C-reactive protein (CRP), interleukin (IL) 6), liver enzyme (alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase), and lipid biomarkers (total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol).

RESULTS

At follow-up blood collection, women were at median age 58.2 (95% CI 51 to 65) years and 26.3 (95% CI 15.7 to 34.1) years since GDM index pregnancy. After multiple adjustment including prepregnancy body mass index (BMI), longer duration of lactation was significantly associated with lower CRP (least squares (LS) mean 1.90 mg/L (95% CI 1.47 to 2.45) for 0-month lactation, 1.98 mg/L (95% CI 1.68 to 2.32) for up to 12-month lactation, 1.67 mg/L (95% CI 1.42 to 1.97) for 12-24 month lactation, and 1.39 mg/L (95% CI 1.19 to 1.62) for >24-month lactation; p trend=0.003) and IL-6 (1.25 pg/L (95% CI 0.94 to 1.68), 1.19 pg/L (95% CI 0.99 to 1.42), 1.04 pg/L (95% CI 0.87 to 1.25), and 0.93 pg/L (95% CI 0.78 to 1.11); p trend=0.04). Longer duration of lactation was associated with lower risk for chronic inflammation using CRP 3 mg/L cut-off in middle-aged women (OR 0.81 (95% CI 0.69 to 0.940 per 1-year increase) with multiple adjustment.

CONCLUSIONS

Longer lifetime duration of lactation was associated with favorable inflammatory biomarker concentrations in middle-aged women with a history of GDM. Chronic inflammatory pathways may be responsible for previously reported associations between lactation and long-term risk for cardiometabolic diseases.

Feasibility and Effectiveness of Telelactation Among Rural Breastfeeding Women

OBJECTIVE

To evaluate the feasibility and impact of telelactation via personal electronic devices on breastfeeding duration and exclusivity among rural women.

METHODS

The Tele-MILC trial, a pragmatic, parallel design trial, recruited 203 women during their postpartum hospitalization in a critical access hospital in Pennsylvania and randomized them to receive telelactation (n = 102) or usual care (n = 101). We used intent-to-treat (ITT) and instrumental variable (IV) approaches to analyze study data for the 187 participants who completed follow-up. The primary outcomes were any breastfeeding and exclusive breastfeeding at 12 weeks postpartum.

RESULTS

Among participants in the telelactation arm, 50% (47/94) reported participating in video calls. At 12 weeks, 71% of participants in the telelactation arm versus 68% of control participants were breastfeeding in the ITT model (3% difference, P = .73), whereas 73% of participants in the telelactation arm versus 68% of control participants were breastfeeding in the IV model (5% difference, P = .74). Among participants who were still breastfeeding at 12 weeks, 51% participants in the telelactation arm were breastfeeding exclusively versus 46% of control participants in the ITT model (5% difference, P = .47), whereas 56% of participants in the telelactation arm were breastfeeding exclusively versus 45% of control participants in the IV model (11% difference, P = .48). In all models, participants in the telelactation arm were breastfeeding at higher rates; however, differences were not statistically significant.

CONCLUSIONS

This trial demonstrated that telelactation can be implemented with a rural underserved population. Though this trial was not powered to detect differences in breastfeeding duration and exclusivity, and none were observed, telelactation remains a promising approach for further investigation. ClinicalTrials.gov Identifier: NCT02870413.

Caregiver Influences on Eating Behaviors in Young Children: A Scientific Statement From the American Heart Association

A substantial body of research suggests that efforts to prevent pediatric obesity may benefit from targeting not just what a child eats, but how they eat. Specifically, child obesity prevention should include a component that addresses reasons why children have differing abilities to start and stop eating in response to internal cues of hunger and satiety, a construct known as eating self‐regulation. This review summarizes current knowledge regarding how caregivers can be an important influence on children's eating self‐regulation during early childhood. First, we discuss the evidence supporting an association between caregiver feeding and child eating self‐regulation. Second, we discuss what implications the current evidence has for actions caregivers may be able to take to support children's eating self‐regulation. Finally, we consider the broader social, economic, and cultural context around the feeding environment relationship and how this intersects with the implementation of any actions. As far as we are aware, this is the first American Heart Association (AHA) scientific statement to focus on a psychobehavioral approach to reducing obesity risk in young children. It is anticipated that the timely information provided in this review can be used not only by caregivers within the immediate and extended family but also by a broad range of community‐based care providers.

Lactation and Maternal Subclinical Atherosclerosis Among Women With and Without a History of Hypertensive Disorders of Pregnancy

Background: We evaluated subclinical cardiovascular disease in relation to lactation history among women with normotensive pregnancies and women with hypertensive pregnancies, a distinction not previously examined. Materials and Methods: The POUCHmoms study included 678 women from a pregnancy cohort who were followed 7-15 years after delivery. We measured blood pressure, lipid levels, carotid intima-media thickness (CIMT), and lactation duration for each live birth (LB) at follow-up. We categorized lactation as never, <6 months/LB, or ≥6 months/LB. We analyzed associations between lactation and cardiometabolic risk factors and CIMT by using analysis of variance and multivariable linear regression (adjusted for age, race, socioeconomic status, smoking, time from last pregnancy, and total parity), which produced adjusted least square mean differences (LSMdiff) between groups. Results: In the normotensive pregnancies group with women who never lactated as the referent (n = 157): Women with some lactation but <6 months/LB (n = 284) had higher high density lipoprotein (HDL) (LSMdiff = +4.47 mg/dL, p = 0.013), lower triglycerides (LSMdiff = -38.1 mg/dL, p = 0.02), and thinner mean CIMT (LSMdiff = -0.03 mm, p = 0.005); women who lactated for ≥6 months/LB (n = 133) also had higher HDL (LSMdiff = +7.59 mg/dL, p < 0.001), lower triglycerides (LSMdiff = -41.6 mg/dL, p = 0.01), and thinner mean CIMT (LSMdiff = -0.03 mm, p = 0.003). After further adjustment for body mass index, associations between lactation and HDL, triglycerides, and mean CIMT persisted. These associations were not detected in women with prior hypertensive pregnancies. Conclusions: Women with a history of normotensive pregnancies and lactation for any duration had a more favorable cardiometabolic profile and were at decreased risk of subclinical atherosclerosis compared with those who never lactated.

The effect of breastfeeding on postpartum glucose tolerance and lipid profiles in women with gestational diabetes mellitus

Background

We aimed to investigate the association of breastfeeding on postpartum glucose levels and lipid profiles in women diagnosed with gestational diabetes mellitus (GDM) and women without GDM.

Methods

We performed a secondary analysis of a cohort study of 243 women, 159 women with GDM and 84 normally glucose tolerant women between 2012 and 2017. At approximately 6-10 weeks postpartum, we measured fasting blood glucose and plasma lipid levels. Breastfeeding behaviour was self-defined as exclusive breastfeeding or not exclusive breastfeeding.

Results

The mean (SD) glucose in the group of women who breastfed exclusively was 4.6 (0.49) mmol/L, compared to 4.9 (0.58) mmol/L (95% CI 0.45, 0.15, p <  0.001) among women who did not exclusively breastfeed. Among women with GDM, the reduction in fasting glucose in women who were breastfeeding was 0.22 mmol/L (95% CI 0.39, 0.05, p = 0.004), and in women who were not GDM, the reduction was 0.14 mmol/L (95% CI 0.37, 0.09, p = 0.24,). After adjustment for GDM status in pregnancy, maternal body mass index (BMI), maternal age and ethnicity, and exclusive breastfeeding was associated with a decreased fasting glucose of 0.19 (95% CI 0.318, 0.061, p = 0.004). After similar adjustment, there was no significant difference in triglycerides, high density lipoprotein cholesterol or low-density lipoprotein cholesterol between women who were breastfeeding and women who were not breastfeeding.

Conclusions

Breastfeeding is associated with a reduction in fasting glucose levels postpartum, but not maternal lipid profile. Breastfeeding may play a role in reducing glucose intolerance in women who have had GDM.

Breastfeeding and maternal cardiovascular risk factors: 1982 Pelotas Birth Cohort

This study evaluated the association of breastfeeding duration with maternal metabolic cardiovascular risk factors among women who have been prospectively followed since birth in a southern Brazilian city. In the unadjusted analysis, total cholesterol was higher among women who never breastfed in relation to those who breastfed ≥12 months. Among women with one livebirth, a shorter duration of breastfeeding was associated with lower HDL, while those with two or more livebirths and that breastfed for shorter time presented lower pulse wave velocity, glycaemia and non-HDL measures. After controlling for confounding variables, the magnitude of these associations decreased, and the confidence intervals included the reference. Concerning the duration of breastfeeding of the last child, the analysis was stratified by time since last birth. After controlling for confounders, systolic blood pressure was lower among women who breastfed 3 to <6 months and had a child within the last five years in relation to those who breastfed ≥6, but no clear trend was observed (p = 0.17). In conclusion, our findings suggest that there is no association between lactation and maternal cardiometabolic risk factors.

Association of breastfeeding, maternal anthropometry and body composition in women at 30 years of age

This study aimed at assessing the association of breastfeeding with maternal body mass index (BMI), waist circumference, fat mass index, fat free mass index, android/gynoid fat ratio and bone mineral density. In 1982, the maternity hospitals in Pelotas, Rio Grande do Sul State, Brazil, were daily visited and all live births were identified and examined. These subjects underwent follow-up for several times. At 30 years of age, the participants were interviewed and examined. Parous women provided information on parity and duration of breastfeeding. Multiple linear regression was used in the multivariate analysis, controlling for genomic ancestry, family income, schooling and smoking at 2004-2005. After controlling for confounding factors, breastfeeding was inversely associated with BMI and fat mass index, whereas breastfeeding per live birth was negatively associated with BMI, waist circumference and fat mass index. Women who had had a child in the last 5 years and had breastfed, showed lower BMI (β = -2.12, 95%CI: -4.2; -0.1), waist circumference (β = -4.46, 95%CI: -8.3; -0.6) and fat mass index (β = -1.79, 95%CI: -3.3; -0.3), whereas no association was observed among those whose last childbirth was > 5 years, but the p-value for the tests of interaction were > 0.05. Our findings suggest that breastfeeding is associated with lower BMI and other adiposity measures, mostly in the first years after delivery. Besides that, it has no negative impact on bone mineral density.

Breastfeeding and long-term maternal metabolic health in the HUNT Study: a longitudinal population-based cohort study

OBJECTIVE

Breastfeeding (BF) has been reported to improve long-term maternal metabolic health in observational studies, but not in the randomised controlled PROBIT study. Research also suggests that maternal pre-pregnant metabolic health may affect BF. We aimed to disentangle effects of BF on long-term maternal metabolic health from effects of pre-pregnant metabolic health on BF duration and long-term metabolic health.

DESIGN

Longitudinal population-based cohort study.

SETTING

Nord-Trøndelag county, Norway.

POPULATION

Women with a first live-born baby (1987-2008) participating in the Nord-Trøndelag Health Study (HUNT).

METHODS

Odds ratios (ORs) for short BF duration (<3 months) by pre-pregnant body mass index (BMI), waist circumference (WCF), blood pressures (BPs), and heart rate (HR) were adjusted for age and smoking using logistic regression. Mixed linear models were used to estimate effects of BF duration (<3, 3-6, >6 months) on mean values of metabolic health parameters from baseline to follow-up.

MAIN OUTCOME MEASURES

Mean change in BMI, WCF, BPs, HR, serum-glucose, and serum-lipids from baseline to follow-up by BF duration categories.

RESULTS

We analysed 1403 women with a median follow-up of 12 years (interquartile range 11-22). Pre-pregnant WCF and HR correlated inversely with BF duration. Pre-pregnant BMI had a u-shaped correlation-pattern with BF duration. We observed similar between-group differences in metabolic health parameters at baseline and at follow-up, which implies that mean change in metabolic health parameters was similar across BF groups. Those women who started out with the best health had the longest BF duration and ended up with the best health, and those women who started out with the poorest health had shortest BF duration and ended up with the poorest health.

CONCLUSIONS

Our results do not support a causal relationship between long BF duration and improved metabolic health. It is more likely that pre-pregnant metabolic health affects both BF duration and long-term metabolic health. Reverse causality can explain previously observed improved long-term metabolic health after BF.

TWEETABLE ABSTRACT

Breastfeeding seems not to affect long-term maternal metabolic health, but good pre-pregnant metabolic health does.

Lifestyle intervention strategies in early life to improve pregnancy outcomes and long-term health of offspring: a narrative review

Adverse exposures during fetal life and the postnatal period influence physical, cognitive and emotional development, and predispose to an increased risk of various chronic diseases throughout the life course. Findings from large observational studies in various populations and experimental animal studies have identified different modifiable risk factors in early life. Adverse maternal lifestyle factors, including overweight, unhealthy diet, sedentary behavior, smoking, alcohol consumption and stress in the preconception period and during pregnancy, are the most common modifiable risk factors leading to a suboptimal in-utero environment for fetal development. In the postnatal period, breastfeeding, infant growth and infant dietary intake are important modifiable factors influencing long-term offspring health outcomes. Despite the large amount of findings from observational studies, translation to lifestyle interventions seems to be challenging. Currently, randomized controlled trials focused on the influence of lifestyle interventions in these critical periods on short-term and long-term maternal and offspring health outcomes are scarce, have major limitations and do not show strong effects on maternal and offspring outcomes. New and innovative approaches are needed to move from describing these causes of ill-health to start tackling them using intervention approaches. Future randomized controlled lifestyle intervention studies and innovative observational studies, using quasi-experimental designs, are needed focused on the effects of an integrated lifestyle advice from preconception onwards on pregnancy outcomes and long-term health outcomes in offspring on a population level.

Effect of Lactation on Maternal Hypertension: A Systematic Review

INTRODUCTION

Hypertension is relatively common in pregnancy, and pregnancy may unmask hypertension among women who are predisposed to it. Lactation may be a means through which to mitigate pregnancy-related vascular risk. The impact of lactation on maternal blood pressure, and the duration of any effect, remains unclear. This study aimed at systematically reviewing the literature evaluating the impact of lactation on the development of hypertension.

MATERIALS AND METHODS

We searched PubMed, including EMBASE and MEDLINE, for studies that reported on the association between breastfeeding and maternal risk of hypertension that were published in a peer-reviewed source. The quality of the studies included was assessed by using the Newcastle-Ottawa Scale.

RESULTS

Nineteen studies met all inclusion criteria for this review. Of the four studies with short-term follow-up, 50% showed a protective association. The fifteen studies with longer-term follow-up were stratified by outcome assessed. Sixty-seven percent of the studies that evaluated for elevated blood pressure and 100% of the studies evaluating for an outcome of hypertension showed a protective association. The minimum duration of lactation associated with a benefit was 1 month. This association was demonstrated in follow-up periods as long as two to three decades. Studies that showed a protective association had overall higher quality ratings.

DISCUSSION

Lactation is associated with a beneficial effect on maternal blood pressure that persists for decades. These results add to the growing body of literature demonstrating the protective association of lactation on maternal cardiovascular risk. Providers may incorporate the decreased risk of hypertension into their counseling on the maternal benefits of lactation.

Methodological challenges in studying the causal determinants of child growth

Background

Previous studies of early life influences on later growth in childhood have varied in their analytical approaches, particularly with respect to 'adjustment' for differences in size at the beginning of the growth period examined.

Methods

We compared three commonly used statistical models to assess the effect of maternal body mass index (BMI) on growth between 6.5 and 11.5 years in a large cohort of Belarusian children, as follows: (Model 1) analysis of the difference in anthropometric measurements between the two ages; (Model 2) analysis of the measurement at 11.5 years after adjustment for the same measurement at 6.5 years; and (Model 3) analysis of the difference in measurements after adjustment for the measurement at 6.5 years (mathematically identical to Model 2).

Results

Among PROBIT children of obese mothers (BMI ≥ 30 kg/m 2 ) vs those of mothers with normal BMI (18.5 to < 25 kg/m 2 ), Model 1 yielded larger increases in most weight and adiposity outcomes than did Model 2. We show that these larger effects arise because Model 2 parameterizes the effect of maternal BMI twice in same model: once for its effect on size at 6.5 years, and a second time for its effect on growth over the 5-year period between 6.5 and 11.5 years. Similar results were obtained in analogous analyses from cohorts in Boston, MA, and Singapore.

Conclusion

Analysing the effect of exposure on change in outcome between two ages (Model 1) is clearly preferable to 'adjustment' for the outcome at the earlier age whenever the exposure under study affects the outcome at the earlier age.

Breastfeeding and maternal cardiovascular risk factors and outcomes: A systematic review

Background

There is growing evidence that breastfeeding has short- and long-term cardiovascular health benefits for mothers. The objectives of this systematic review were to examine the association between breastfeeding and maternal cardiovascular risk factors and outcomes that have not previously been synthesized systematically, including metabolic syndrome, hypertension and cardiovascular disease.

Methods and findings

This systematic review meets PRISMA guidelines. The MEDLINE, EMBASE and CINAHL databases were systematically searched for relevant publications of any study design from the earliest publication date to March 2016. The reference lists from selected articles were reviewed, and forward and backward referencing were conducted. The methodological quality of reviewed articles was appraised using validated checklists.

Twenty-one studies meeting the inclusion criteria examined the association between self-reported breastfeeding and one or more of the following outcomes: metabolic syndrome/metabolic risk factors (n = 10), inflammatory markers/adipokines (n = 2), hypertension (n = 7), subclinical cardiovascular disease (n = 2), prevalence/incidence of cardiovascular disease (n = 3) and cardiovascular disease mortality (n = 2). Overall, 19 studies (10 cross-sectional/retrospective, 9 prospective) reported significant protective effects of breastfeeding, nine studies (3 cross-sectional/retrospective, 5 prospective, 1 cluster randomized controlled trial) reported non-significant findings and none reported detrimental effects of breastfeeding. In most studies reporting significant associations, breastfeeding remained associated with both short- and long-term maternal cardiovascular health risk factors/outcomes, even after covariate adjustment. Findings from several studies suggested that the effects of breastfeeding may diminish with age and a dose-response association between breastfeeding and several metabolic risk factors. However, further longitudinal studies, including studies that measure exclusive breastfeeding, are needed to confirm these findings.

Conclusions

The evidence from this review suggests that breastfeeding is associated with cardiovascular health benefits. However, results should be interpreted with caution as the evidence gathered for each individual outcome was limited by the small number of observational studies. Additional prospective studies are needed.

PROSPERO registration number

CRD42016047766.

Support for healthy breastfeeding mothers with healthy term babies

BACKGROUND

There is extensive evidence of important health risks for infants and mothers related to not breastfeeding. In 2003, the World Health Organization recommended that infants be breastfed exclusively until six months of age, with breastfeeding continuing as an important part of the infant's diet until at least two years of age. However, current breastfeeding rates in many countries do not reflect this recommendation.

OBJECTIVES

To describe forms of breastfeeding support which have been evaluated in controlled studies, the timing of the interventions and the settings in which they have been used.To examine the effectiveness of different modes of offering similar supportive interventions (for example, whether the support offered was proactive or reactive, face-to-face or over the telephone), and whether interventions containing both antenatal and postnatal elements were more effective than those taking place in the postnatal period alone.To examine the effectiveness of different care providers and (where information was available) training.To explore the interaction between background breastfeeding rates and effectiveness of support.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (29 February 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing extra support for healthy breastfeeding mothers of healthy term babies with usual maternity care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

This updated review includes 100 trials involving more than 83,246 mother-infant pairs of which 73 studies contribute data (58 individually-randomised trials and 15 cluster-randomised trials). We considered that the overall risk of bias of trials included in the review was mixed. Of the 31 new studies included in this update, 21 provided data for one or more of the primary outcomes. The total number of mother-infant pairs in the 73 studies that contributed data to this review is 74,656 (this total was 56,451 in the previous version of this review). The 73 studies were conducted in 29 countries. Results of the analyses continue to confirm that all forms of extra support analyzed together showed a decrease in cessation of 'any breastfeeding', which includes partial and exclusive breastfeeding (average risk ratio (RR) for stopping any breastfeeding before six months 0.91, 95% confidence interval (CI) 0.88 to 0.95; moderate-quality evidence, 51 studies) and for stopping breastfeeding before four to six weeks (average RR 0.87, 95% CI 0.80 to 0.95; moderate-quality evidence, 33 studies). All forms of extra support together also showed a decrease in cessation of exclusive breastfeeding at six months (average RR 0.88, 95% CI 0.85 to 0.92; moderate-quality evidence, 46 studies) and at four to six weeks (average RR 0.79, 95% CI 0.71 to 0.89; moderate quality, 32 studies). We downgraded evidence to moderate-quality due to very high heterogeneity.We investigated substantial heterogeneity for all four outcomes with subgroup analyses for the following covariates: who delivered care, type of support, timing of support, background breastfeeding rate and number of postnatal contacts. Covariates were not able to explain heterogeneity in general. Though the interaction tests were significant for some analyses, we advise caution in the interpretation of results for subgroups due to the heterogeneity. Extra support by both lay and professionals had a positive impact on breastfeeding outcomes. Several factors may have also improved results for women practising exclusive breastfeeding, such as interventions delivered with a face-to-face component, high background initiation rates of breastfeeding, lay support, and a specific schedule of four to eight contacts. However, because within-group heterogeneity remained high for all of these analyses, we advise caution when making specific conclusions based on subgroup results. We noted no evidence for subgroup differences for the any breastfeeding outcomes.

AUTHORS' CONCLUSIONS

When breastfeeding support is offered to women, the duration and exclusivity of breastfeeding is increased. Characteristics of effective support include: that it is offered as standard by trained personnel during antenatal or postnatal care, that it includes ongoing scheduled visits so that women can predict when support will be available, and that it is tailored to the setting and the needs of the population group. Support is likely to be more effective in settings with high initiation rates. Support may be offered either by professional or lay/peer supporters, or a combination of both. Strategies that rely mainly on face-to-face support are more likely to succeed with women practising exclusive breastfeeding.

Clinical study on cluster care to prevent multi-drug resistant infection in ICU patients with severe encephalopathy

The value of clinical cluster nursing in the prevention of multi-drug resistant (MDR) infection in patients with severe encephalopathy in ICU was evaluated. ICU patients (n=129) diagnosed with severe encephalopathy between 2012 and 2014 were selected as the study group, while 106 cases of ICU patients diagnosed with severe encephalopathy between 2010 and 2012 were retrospectively selected as the control group. Control group patients were offered conventional integrated nursing care, while the study group patients were offered cluster nursing care. The differences in infection rate, colony and quantity, infection time, number, mortality rate and hospital stays between the two groups were compared and analyzed. Observations on the infection rate, diagnosis time, total number of infection, mortality rate caused by infection and hospital stays were lower in the study group patients than in controls (P<0.05). The patients in the study group had a much lower drug-resistant infection rate than that in the control group (P<0.05). In the patient groups there were infections with methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli, although the quantities of the above pathogenic microbe colonies in the study group were notably less than those in the control group (P<0.05). In conclusion, cluster nursing care effectively prevents MDR infections of ICU patients with severe encephalopathy and reduces the mortality rate, thus having an excellent clinical significance.

Effects of lactation on postpartum blood pressure among women with gestational hypertension and preeclampsia

BACKGROUND

Women with a history of hypertensive disorders of pregnancy are at an increased risk of hypertension and cardiovascular disease in later life. Lactation has been associated with a reduced risk of maternal hypertension, both in the postpartum period and later life. However, little is known about whether lactation is also cardioprotective in women with hypertensive disorders of pregnancy such as preeclampsia or gestational hypertension.

OBJECTIVE

This study aimed to characterize the relationship between lactation and postpartum blood pressure among women with preeclampsia and gestational hypertension.

STUDY DESIGN

Data were obtained from women who participated in the Prenatal Exposures and Preeclampsia Prevention study (n = 379; 66% African American; 85% overweight or obese). Women enrolled during pregnancy and attended a postpartum visit (on average, 9.1 months after delivery) during which data on lactation duration and blood pressure were collected. The significance of the associations between postpartum blood pressure and lactation among women who remained normotensive during pregnancy, developed gestational hypertension, or developed preeclampsia were assessed with an analysis of variance. Linear regression models were used to adjust for maternal age, race, education, prepregnancy weight, and time since delivery.

RESULTS

Gestational hypertension affected 42 subjects (11%) and preeclampsia affected 33 (9%). Lactation was reported by 217 (57%) with 78 (21%) reporting ≥ 6 months of lactation. Women who lactated were somewhat older, more educated, and had higher socioeconomic status. Among women who had gestational hypertension, lactation was associated with lower systolic blood pressure (P = .02) and diastolic blood pressure (P = .02). This association persisted after adjustment for age, race, education, prepregnancy weight, and time since delivery. However, for women who had preeclampsia and women who remained normotensive during pregnancy, lactation was not associated with postpartum blood pressure in either bivariate or multivariate analyses.

CONCLUSION

This study found that lactation is associated with lower postpartum blood pressure among overweight women who develop gestational hypertension but not among women who develop preeclampsia. Future studies are needed to explore the association of lactation and blood pressure in later life for women with hypertensive disorders of pregnancy.

Lactation and Maternal Cardio-Metabolic Health

Researchers hypothesize that pregnancy and lactation are part of a continuum, with lactation meant to "reset" the adverse metabolic profile that develops as a part of normal pregnancy, and that when lactation does not occur, women maintain an elevated risk of cardio-metabolic diseases. Several large prospective and retrospective studies, mostly from the United States and other industrialized countries, have examined the associations between lactation and cardio-metabolic outcomes. Less evidence exists regarding an association of lactation with maternal postpartum weight status and dyslipidemia, whereas more evidence exists for an association with diabetes, hypertension, and subclinical and clinical cardiovascular disease.

European Code against Cancer 4th Edition: Obesity, body fatness and cancer

It is estimated that over half the population of the European Union (EU) is overweight or obese due to an imbalance between energy expenditure and energy intake; this is related to an obesogenic environment of sociocultural, economic and marketing challenges to the control of body weight. Excess body fat is associated with nine cancer sites - oesophagus, colorectum, gall bladder, pancreas, postmenopausal breast, endometrium, ovary, kidney and prostate (advanced) - and 4-38% of these cancers (depending on site and gender) can be attributed to overweight/obesity status. Metabolic alterations which accompany excess body weight are accompanied by increased levels of inflammation, insulin, oestrogens and other hormonal factors. There are some indications that intentional weight loss is associated with reduced cancer incidence (notably in postmenopausal breast and endometrial cancers). Excess body weight is also a risk factor for several other diseases, including diabetes and heart disease, and is related to higher risk of premature death. In reviewing the current evidence related to excess body fat and cancer, the European Code against Cancer Nutrition Working Group has developed the following recommendation: 'Take action to be a healthy body weight'.

Associations Among Lactation, Maternal Carbohydrate Metabolism, and Cardiovascular Health

In mammalian reproductive physiology, lactation follows pregnancy; growing evidence suggests that disruption of this physiology affects a woman's lifetime risk of metabolic disease. These differences may reflect lactation-induced mobilization of fat stores and modulation of maternal stress reactivity. In addition, confounders may play a role: women who breastfeed for long durations are more likely to engage in other healthy behaviors, and obesity and insulin resistance may interfere with breastfeeding physiology. These findings underscore the importance of evidenced-based care to enable women to achieve their infant feeding goals.

Lactation Duration and Midlife Atherosclerosis

OBJECTIVE

To evaluate lactation duration in relation to subsequent atherosclerosis in women during midlife.

METHODS

The Coronary Artery Risk Development in Young Adults study is a multicenter prospective cohort that enrolled 2,787 women in 1985-1986 (ages 18-30 years, 52% black, 48% white), of whom 2,014 (72%) attended the 20-year follow-up examination in 2005-2006. We selected 846 women (46% black) without heart disease or diabetes at baseline who delivered one or more times after the baseline evaluation, had cardiometabolic risk factors measured at baseline, and had maximum common carotid intima-media thickness (mm) measured at the 20-year follow-up examination in 2005-2006. Lactation duration was summed across all postbaseline births for each woman and (n, women) categorized as: 0 to less than 1 month (n=262), 1 to less than 6 months (n=210), 6 to less than 10 months (n=169), and 10 months or greater (n=205). Multiple linear regression models estimated mean common carotid intima-media thickness (95% confidence interval) and mean differences among lactation duration groups compared with the 0 to less than 1-month group adjusted for prepregnancy obesity, cardiometabolic status, parity, and other risk factors.

RESULTS

Lactation duration had a graded inverse association with common carotid intima-media thickness; mean differences between 10 months or greater compared with 0 to less than 1 month ranged from -0.062 mm for unadjusted models (P trend <.001) to -0.029 mm for models fully adjusted for prepregnancy body mass index (BMI) and cardiometabolic risk factors, parity, smoking, and sociodemographics (P trend=.010). Stepwise addition of potential mediators (BMI, systolic blood pressure at the 20-year follow-up examination) modestly attenuated the lactation and common carotid intima-media thickness association to -0.027 and -0.023 mm (P trend=.019 and .054).

CONCLUSION

Shorter lactation duration is associated with subclinical atherosclerosis independent of prepregnancy cardiometabolic risk factors and traditional risk factors. The magnitude of differences in carotid artery intima-media thickness may represent greater vascular aging. Lactation may have long-term benefits that lower cardiovascular disease risk in women.

LEVEL OF EVIDENCE

II.

Best (but oft-forgotten) practices: designing, analyzing, and reporting cluster randomized controlled trials

Cluster randomized controlled trials (cRCTs; also known as group randomized trials and community-randomized trials) are multilevel experiments in which units that are randomly assigned to experimental conditions are sets of grouped individuals, whereas outcomes are recorded at the individual level. In human cRCTs, clusters that are randomly assigned are typically families, classrooms, schools, worksites, or counties. With growing interest in community-based, public health, and policy interventions to reduce obesity or improve nutrition, the use of cRCTs has increased. Errors in the design, analysis, and interpretation of cRCTs are unfortunately all too common. This situation seems to stem in part from investigator confusion about how the unit of randomization affects causal inferences and the statistical procedures required for the valid estimation and testing of effects. In this article, we provide a brief introduction and overview of the importance of cRCTs and highlight and explain important considerations for the design, analysis, and reporting of cRCTs by using published examples.

Invited Commentary: Breastfeeding and Maternal Cardiovascular Health--Weighing the Evidence

Recently, there has been growing interest in understanding the ways in which lactation affects maternal health. The accompanying article by Palmer et al. (Am J Epidemiol. 2015;181(12):932-939), particularly their finding that prepregnancy obesity modifies the relationship between lactation and postpartum weight gain, makes an important contribution to this field. In this commentary, I discuss these findings within the context of other recent literature which indicates that whether or not a mother breastfeeds her newborn appears to be a powerful predictor of the mother's future risk of developing diabetes, hypertension, and cardiovascular disease, independent of maternal weight or body mass index in later life.

Lactation in Relation to Long-Term Maternal Weight Gain in African-American Women

We assessed the relationship of lactation to long-term maternal weight gain among African-American women, who have a lower prevalence of lactation and a higher prevalence of obesity than other US women. A pregnancy cohort of 3,147 African-American women from the Black Women's Health Study who gave birth for the first time between 1995 and 2003 was followed for 8 years postpartum. Participants provided data on weight, lactation, gestational weight gain, education, diet, and exercise. Mean differences in weight gain were estimated in multivariable models. Overall, lactation was not associated with mean weight gain. However, the association was modified by prepregnancy body mass index (BMI; weight (kg)/height (m)2) (P for interaction=0.03): Among women with BMI<30 prior to the pregnancy, mean weight gain decreased with increasing months of lactation (P for trend<0.01), whereas among obese women (BMI≥30), mean weight gain increased with increasing duration of lactation (P for trend=0.04). Adjusted mean differences for ≥12 months of lactation relative to no lactation were -1.56 kg (95% confidence interval: -2.50, -0.61) among nonobese women and 2.33 kg (95% confidence interval: -0.35, 5.01) among obese women. The differences in postpartum mean weight gain persisted over the 8-year study period. Residual confounding by factors more common in women who breastfeed longer may have influenced the results.

Associations of maternal material hardships during childhood and adulthood with prepregnancy weight, gestational weight gain, and postpartum weight retention

BACKGROUND

We examined associations of material hardship with prepregnancy body mass index (BMI), gestational weight gain (GWG), and substantial postpartum weight retention (SPPWR; ≥5 kg at 1 year).

METHODS

We studied 2128 women in Project Viva, a Boston-area cohort with recruitment during1999-2002. At recruitment, women reported whether they experienced material hardship, defined as having ever received public assistance, welfare, or lacked basic necessities (food, rent, or medical care) during childhood, in adulthood before pregnancy, and/or in pregnancy. We used multivariable logistic models adjusted for age, race/ethnicity, and parity (and prepregnancy BMI for GWG and SPPWR) to examine associations of material hardship with the three weight-related outcomes (BMI, GWG, and SPPWR).

RESULTS

Mean age was 31.8 (standard deviation, 5.2) years; 66% of women were white, 16% were obese (prepregnancy BMI ≥30.0 kg/m(2)), 50% experienced excessive GWG, and 17% experienced SPPWR. Material hardship was most common during childhood (n=192, 9%), followed by adulthood (102, 5%), and pregnancy (41, 2%). Hardship in adulthood was associated with prepregnancy obesity (BMI ≥30 kg/m(2) vs. 18.5 to <25.0 kg/m(2)), odds ratio ([OR] 2.35, 95% confidence interval [CI] 1.29, 4.31), but hardship in childhood was not (OR 1.26, 95% CI 0.80, 1.98). Hardship in childhood was associated with excess GWG (OR 1.45, 95% CI 0.99, 2.14), but hardship in adulthood or during pregnancy was not. We saw trends among hardship in each of the periods and associations with SPPWR, but all confidence intervals included the null.

CONCLUSION

The timing of hardship exposure may differently influence weight before, during, and after pregnancy.

Maternal weight change from prepregnancy to 7 years postpartum--the influence of behavioral factors

OBJECTIVE

We studied the influence of maternal behavior on weight change from prepregnancy to 7 years postpartum.

METHODS

We used linear regression to study the independent and combined associations between self-reported behavior in pregnancy (dietary intake, leisure-time exercise, sedentary activity, smoking) and postpartum (breastfeeding duration and smoking) on weights at 6 months, 18 months, and 7 years postpartum.

RESULTS

Women's average 7-year weight gain was 2.07 kg, with 23% gaining >5 kg. Multivariable analyses suggested that women with healthier dietary intake, more leisure-time exercise, less sedentary behavior, and longer duration of breastfeeding on average gained 1.66 kg [95% confidence interval (CI): 1.40; 1.91] with a significantly reduced odds [OR 0.56 (95% CI: 0.49; 0.64)] of gaining >5 kg from prepregnancy to 7 years postpartum compared to women with none or one of these behaviors [mean gain 3.03 kg (95% CI: 2.68; 3.39)]. Women who ceased smoking had higher long-term weight gain than nonsmokers, but not smokers.

CONCLUSIONS

Adherence to healthy behaviors during pregnancy lowered long-term weight gain considerably by lowering postpartum weight retention and subsequent weight gain. Public health efforts to help mothers achieve healthy behaviors might prevent childbearing-related weight gain.