Maternal and perinatal health outcomes by body mass index category

Impact of maternal obesity on offspring adipose tissue: lessons for the clinic

Maternal obesity is a major risk factor for the subsequent development of obesity and Type 2 diabetes in the child. This relationship appears to be driven largely by the exposure of the fetus to an increased nutrient supply during critical periods of development, which results in persistent changes in the structure and function of key systems involved in the regulation of energy balance, appetite and fat deposition. One of the key targets is the fat cell, or adipocyte, in which prenatal overnutrition programs a heightened capacity for fat storage. The increasing prevalence of maternal obesity has led to an urgent need for strategies to break the resulting intergenerational cycle of obesity and metabolic disease. This review will discuss the relationship between maternal obesity and poor metabolic health of the offspring, with a particular focus on the involvement of adipose tissue, recent clinical studies examining potential strategies for intervention and priority areas for further research.

The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial

BACKGROUND

Overweight and obesity is a significant health concern during pregnancy. Our aim was to investigate the effect of providing antenatal dietary and lifestyle advice to women who are overweight or obese on components of maternal diet and physical activity.

METHODS

We conducted a randomised controlled trial, in which pregnant women with a body mass index≥25 kg/m2, and singleton gestation between 10(+0) to 20(+0) weeks were recruited and randomised to Lifestyle Advice (involving a comprehensive dietary and lifestyle intervention over their pregnancy) or Standard Care. Within the intervention group, we conducted a nested randomised trial in which a subgroup of women were further randomised to receive access to supervised group walking sessions in addition to the standard information presented during the intervention contacts (the Walking group) or standard information only. The outcome measures were maternal dietary intake, (including food groups, macronutrient and micronutrient intake, diet quality (using the Healthy Eating Index; HEI), dietary glycaemic load, and glycaemic index) and maternal physical activity. Women completed the Harvard Semi-Structured Food Frequency Questionnaire, and the Short Questionnaire to Assess Health-enhancing Physical Activity (SQUASH), at trial entry, 28 and 36 weeks' gestational age, and 4 months postpartum. Analyses were performed on an intention-to-treat basis, using linear mixed effects models with adjustment for the stratification variables.

RESULTS

Women randomised to Lifestyle Advice demonstrated a statistically significant increase in the number of servings of fruit and vegetables consumed per day, as well as increased consumption of fibre, and reduced percentage energy intake from saturated fats (P<0.05 for all). Maternal HEI was significantly improved at both 28 (73.35±6.62 versus 71.86±7.01; adjusted difference in means 1.58; 95% CI 0.89 to 2.27; P<0.0001) and 36 (72.95±6.82 versus 71.17±7.69; adjusted difference in means 1.77; 95% CI 1.01 to 2.53; P<0.0001) weeks. There were no differences in dietary glycaemic index or glycaemic load. Women randomised to Lifestyle Advice also demonstrated greater total physical activity (adjusted difference in means 359.76 metabolic equivalent task units (MET) minutes/week; 95% CI 74.87 to 644.65; P=0.01) compared with women receiving Standard Care. The supervised walking group was poorly utilised.

CONCLUSIONS

For women who are overweight or obese, antenatal lifestyle advice improves maternal diet and physical activity during pregnancy. Please see related articles: http://www.biomedcentral.com/1741-7015/12/163 and http://www.biomedcentral.com/1741-7015/12/201.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ( ACTRN12607000161426).

The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on neonatal health outcomes: the LIMIT randomised trial

BACKGROUND

Overweight and obesity during pregnancy represents a considerable health burden. While research has focused on interventions to limit gestational weight gain, there is little information describing their impact on neonatal health. Our aim was to investigate the effect on a range of pre-specified secondary neonatal outcomes of providing antenatal dietary and lifestyle advice to women who are overweight or obese.

METHODS

We report a range of pre-specified secondary neonatal outcomes from a large randomised trial in which antenatal dietary and lifestyle advice was provided to women who were overweight or obese. Pregnant women were eligible for participation with a body mass index of 25 kg/m(2) or over, and singleton gestation between 10(+0) and 20(+0) weeks. Outcome measures included gestational age at birth; Apgar score below 7 at 5 minutes of age; need for resuscitation at birth; birth weight above 4.5 kg or below 2.5 kg; birth weight, length and head circumference (and Z-scores); admission to the nursery; respiratory distress syndrome; and postnatal length of stay. Data relating to the primary outcome (large for gestational age infants defined as birth weight above the 90th centile) and birth weight above 4 kg have been reported previously. Analyses used intention-to-treat principles.

RESULTS

In total, 2,142 infants were included in the analyses. Infants born to women following lifestyle advice were significantly less likely to have birth weight above 4.5 kg (2.15% versus 3.69%; adjusted risk ratio (aRR)=0.59; 95% confidence interval (CI) 0.36 to 0.98; P=0.04), or respiratory distress syndrome (1.22% versus 2.57%; aRR=0.47; 95% CI 0.24 to 0.90; P=0.02), particularly moderate or severe disease, and had a shorter length of postnatal hospital stay (3.94±7.26 days versus 4.41±9.87 days; adjusted ratio of means 0.89; 95% CI 0.82 to 0.97; P=0.006) compared with infants born to women who received Standard Care.

CONCLUSIONS

For women who are overweight or obese, antenatal dietary and lifestyle advice has health benefits for infants, without an increase in the risk of harm. Continued follow-up into childhood will be important to assess the longer-term effects of a reduction in high infant birth weight on risk of child obesity. Please see related articles: http://www.biomedcentral.com/1741-7015/12/161 and http://www.biomedcentral.com/1741-7015/12/201 .

CLINICAL TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ( ACTRN12607000161426 ).

Association between physical activity in obese pregnant women and pregnancy outcomes: the UPBEAT pilot study

BACKGROUND

Obesity in pregnancy is associated with fetal macrosomia, a raised neonatal fat mass and an increased risk of obesity and poor metabolic health in childhood which persists into adulthood. The offspring of obese women are more likely to be obese than the offspring of lean women when they become pregnant themselves, perpetuating a cycle of obesity and its associated negative metabolic consequences. Increasing physical activity during pregnancy could improve insulin sensitivity and reduce the risk of maternal and offspring adverse outcomes. The UK Pregnancy Better Eating and Activity Trial (UPBEAT) is a trial of a complex intervention designed to improve pregnancy outcomes through dietary changes and physical activity. Data from the pilot trial of 183 women were available for analysis. The relationship between the time spent at different physical activity levels and maternal and infant pregnancy outcomes was examined.

KEY MESSAGES

Strong evidence exists that physical activity improves insulin sensitivity in non-pregnant populations, and lifestyle interventions of proven effectiveness in non-pregnant populations have been developed. Women who are active in pregnancy demonstrate better glucose control and favourable pregnancy outcomes. There is a lack of effective interventions to support obese pregnant women to be physically active.

CONCLUSIONS

No difference was detected in objectively measured physical activity between women randomised to the intervention and control arms of the UPBEAT pilot trial. Light-intensity physical activity was lower in early pregnancy in women who delivered macrosomic infants. Maternal sedentary time at 35-36 weeks' gestation was positively associated and moderate-intensity physical activity was inversely associated with neonatal abdominal circumference. Maternal physical activity is associated with infant birth weight and abdominal circumference and is an appropriate target for intervention to improve infant outcomes. The challenge remains to develop an effective intervention to support obese pregnant women to be physically active.

Dietary and lifestyle advice for pregnant women who are overweight or obese: the LIMIT randomized trial

Overweight and obesity during pregnancy are common and are associated with an increased risk of adverse health outcomes for both the mother and the infant. However, robust evidence about the effect of antenatal dietary and lifestyle interventions on health outcomes is lacking. We conducted a multicenter, randomized trial, recruiting 2,212 women (from 3 public maternity hospitals across South Australia) with a singleton pregnancy between 10⁺⁰ and 20⁺⁰ weeks' gestation and a BMI ≥25. The women were randomized to lifestyle advice (n = 1,108) or standard care (n = 1,104). Women randomized to lifestyle advice participated in a comprehensive dietary and lifestyle intervention over the course of their pregnancy (delivered by research staff), while women randomized to standard care received pregnancy care according to local guidelines, which did not include such information. Provision of the lifestyle intervention was associated with a significant 18% relative risk reduction in the chance of infants being born with a birth weight above 4 kg. No other significant differences were identified in maternal pregnancy and birth outcomes between the two treatment groups. Observational studies highlight the association between a high infant birth weight and the subsequent risk of childhood and adulthood obesity. Antenatal interventions that are effective in reducing high infant birth weights therefore represent a significant strategy to tackle obesity from a population health perspective, while ongoing interrogation of the biospecimens and measurements, including ongoing childhood follow-up, will provide a unique opportunity to evaluate the mechanistic pathways of maternal-to-infant/childhood obesity.

Developing a clinical care pathway for obese pregnant women: A quality improvement project

PROBLEM

Obesity in pregnancy is associated with an increased incidence of maternal and foetal morbidity and mortality, from conditions like preeclampsia, gestational diabetes, preterm birth and stillbirth. Between 20% and 25% of pregnant women in Australia are presenting to their first antenatal appointment with a body mass index (BMI) ≥ 30 kg/m(2), defined as obesity in pregnancy. These figures are concerning for midwifery and obstetric staff directly involved in the clinical care of these women and their families. In the absence of national or state clinical practice guidelines for managing the risks for obese pregnant women, a local quality improvement project was conducted.

AIM

To plan, implement, and evaluate the impact of an alternative clinical care pathway for pregnant women with a BMI ≥ 35 kg/m(2) at their first antenatal visit.

PROJECT SETTING

The project was undertaken in the antenatal clinic of a rural referral hospital in NSW, Australia.

SUBJECTS

Eighty-two women with a BMI ≥ 35 kg/m(2) were eligible for the alternative care pathway, offered between January and December 2010.

INTERVENTION

The alternative care pathway included the following options, in addition to usual care: written information on obesity in pregnancy, referral to a dietitian, early plus repeat screening for gestational diabetes, liver and renal function pathology tests, serial self-weighing, serial foetal growth ultrasounds, and a pre-labour anaesthetic consultation.

FINDINGS

Despite being educated on the risk associated with obesity in pregnancy, women did not take up the offers of dietetic support or self-weighing at each antenatal visit. Ultrasounds were well received and most women underwent gestational diabetes screening.

Overweight and obese women's perceptions about making healthy change during pregnancy: a mixed method study

Overweight and obesity during pregnancy is associated with risk of a range of adverse health outcomes. While intervention studies aim to promote behavioral change, little is known about the underlying psychological mechanisms facilitating and hindering change. The aim of this study was to evaluate overweight and obese women's perceptions of making behavior change during pregnancy. We explored beliefs through self-administrated questionnaires (n = 464) and semi-structured face-to-face interviews (n = 26). Questions were designed according to the Health Belief Model. A triangulation protocol was followed to combine quantitative and qualitative data. A total of 269 women (58 %) indicated that high gestational weight gain is a concern, with 348 (75 %) indicating excessive weight gain is associated with complications during pregnancy or child birth. Women were aware of maternal complications associated with high gestational weight gain, but had more limited awareness of neonatal complications. While most women indicated in questionnaires that healthy eating and physical activity were associated with improved health during pregnancy, they were unable to identify specific benefits at interview. Barriers to making healthy behavior changes were highly individualized, the main barrier being lack of time. While the majority (91 %) of women indicated that they would make behavior changes if the change made them feel better, only half felt confident in their ability to do so. Interventions for overweight and obese pregnant women should incorporate education about neonatal health consequences and benefits of healthy behavior change in addition to incorporating strategies to enhance self-efficacy.

Preventing maternal and early childhood obesity: the fetal flaw in Australian perinatal care

Almost half of Australian women of child-bearing age are overweight or obese, with a rate of 30-50% reported in early pregnancy. Maternal adiposity is a costly challenge for Australian obstetric care, with associated serious maternal and neonatal complications. Excess gestational weight gain is an important predictor of offspring adiposity into adulthood and higher maternal weight later in life. Current public health and perinatal care approaches in Australia do not adequately address excess perinatal maternal weight or gestational weight gain. This paper argues that the failure of primary health-care providers to offer systematic advice and support regarding women's weight and related lifestyle behaviours in child-bearing years is an outstanding 'missed opportunity' for prevention of inter-generational overweight and obesity. Barriers to action could be addressed through greater attention to: clinical guidelines for maternal weight management for the perinatal period, training and support of maternal health-care providers to develop skills and confidence in raising weight issues with women, a variety of weight management programs provided by state maternal health services, and clear referral pathways to them. Attention is also required to service systems that clearly define roles in maternal weight management and ensure consistency and continuity of support across the perinatal period.

The effects of prenatal exposure to a 'junk food' diet on offspring food preferences and fat deposition can be mitigated by improved nutrition during lactation

Exposure to a maternal junk food (JF) diet in utero and during the suckling period has been demonstrated to increase the preference for palatable food and increase the susceptibility to diet-induced obesity in adult offspring. We aimed to determine whether the effects of prenatal exposure to JF could be ameliorated by cross-fostering offspring onto dams consuming a standard rodent chow during the suckling period. We report here that when all offspring were given free access to the JF diet for 7 weeks from 10 weeks of age, male offspring of control (C) or JF dams that were cross-fostered at birth onto JF dams (C-JF, JF-JF), exhibited higher fat (C-C: 12.3 ± 0.34 g/kg/day; C-JF: 14.7 ± 1.04 g/kg/day; JF-C: 11.5 ± 0.41 g/kg/day; JF-JF: 14.0 ± 0.44 g/kg/day; P < 0.05) and overall energy intake (C-C: 930.1 ± 18.56 kJ/kg/day; C-JF: 1029.0 ± 82.9 kJ/kg/day; JF-C: 878.3 ± 19.5 kJ/kg/day; JF-JF: 1003.4 ± 25.97 kJ/kg/day; P < 0.05) than offspring exposed to the JF diet only before birth (JF-C) or not at all (C-C). Female offspring suckled by JF dams, despite no differences in food intake, had increased fat mass as percentage of body weight (C-C: 19.9 ± 1.33%; C-JF: 22.8 ± 1.57%; JF-C: 17.4 ± 1.03%; JF-JF: 22.0 ± 1.0%; P < 0.05) after 3 weeks on the JF diet. No difference in fat mass was observed in male offspring. These findings suggest that the effects of prenatal exposure to a JF diet on food preferences in females and susceptibility to diet-induced obesity in males can be prevented by improved nutrition during the suckling period.

Periconception weight loss: common sense for mothers, but what about for babies?

Obesity in the childbearing population is increasingly common. Obesity is associated with increased risk for a number of maternal and neonatal pregnancy complications. Some of these complications, such as gestational diabetes, are risk factors for long-term disease in both mother and baby. While clinical practice guidelines advocate for healthy weight prior to pregnancy, there is not a clear directive for achieving healthy weight before conception. There are known benefits to even moderate weight loss prior to pregnancy, but there are potential adverse effects of restricted nutrition during the periconceptional period. Epidemiological and animal studies point to differences in offspring conceived during a time of maternal nutritional restriction. These include changes in hypothalamic-pituitary-adrenal axis function, body composition, glucose metabolism, and cardiovascular function. The periconceptional period is therefore believed to play an important role in programming offspring physiological function and is sensitive to nutritional insult. This review summarizes the evidence to date for offspring programming as a result of maternal periconception weight loss. Further research is needed in humans to clearly identify benefits and potential risks of losing weight in the months before conceiving. This may then inform us of clinical practice guidelines for optimal approaches to achieving a healthy weight before pregnancy.

Anthropometric predictors of gestational hypertensive disorders in a remote aboriginal community: a nested case-control study

Background

Australian Aboriginal women tend to have body shape and pregnancy risk profiles different from other Australian women. This study aims to examine the associations of anthropometric indices with gestational hypertensive disorders (GHD), and to determine the index that can best predict the risk of this condition occurring during pregnancy.

Methods

This is a nested case–control study. Baseline body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were measured as part of a broader health screening program between 1992 and 1995 in a remote Aboriginal community. All subsequent pregnancies among the original participants were identified during 20 year follow-up period through hospital records (up to May 2012). Twenty eight women were diagnosed as having GHD, each of whom were individually matched by age at baseline with five women who were hospitalised for other pregnancy-related conditions and were free from GHD (n = 140). The associations of the baseline anthropometric measurements with GHD were assessed using conditional logistic regression.

Results

The best predictor of GHD was WC (OR = 1.8; (95% CI, 1.1-2.9) for one standard deviation increase in WC), followed by BMI with the corresponding OR = 1.7 (95% CI, 1.1- 2.6). Other measurements, HC, WHR, and WHtR, were also positively associated with GHD, but those associations were not statistically significant.

Conclusions

WC and BMI prior to pregnancy are anthropometric predictors of GHD in Aboriginal women, and WC is the best predictor. These findings imply the importance of early weight control in preventing GHD in Aboriginal women.

Physical activity levels during pregnancy and gestational weight gain among women who are overweight or obese

ISSUE ADDRESSED

There is contradictory research assessing physical activity patterns during pregnancy and postpartum among women who are overweight or obese. The aim of this study was to evaluate physical activity among overweight and obese women over the course of pregnancy and the initial postpartum period.

METHODS

Three hundred and five overweight or obese pregnant women completed physical-activity questionnaires at three time points during pregnancy and at 4-months postpartum.

RESULTS

Physical activity declined between early pregnancy and 28-weeks gestation (P<0.001) and declined further at 36-weeks gestation (P<0.001) before increasing significantly at 4-months postpartum (P<0.001). However, reported activity at 4-months postpartum remained significantly lower than that reported in early pregnancy (P<0.001). There was no significant difference either cross-sectionally or for changes over pregnancy and postpartum for total levels or categories of physical activity for women with different body mass index (BMI) or gestational weight gain (GWG). BMI was the only independent predictor of the change in total physical activity over the study and GWG, with women with higher BMI having larger decline of physical activity (β=0.114, s.e.=0.750, P=0.032) and less GWG (β=-0.253, s.e.=0.063, P<0.001).

CONCLUSIONS

Physical activity declined significantly between early pregnancy and 28-weeks gestation, with a further decline to 36-weeks gestation. At 4-months postpartum, physical activity significantly increased but not to the level of that reported at early pregnancy. SO WHAT?: The promotion of appropriate physical activity should be implemented early in pregnancy and postpartum to prevent the decline in activity we have observed in overweight and obese women. Future research should also explore the barriers and enablers to women engaging in exercise during pregnancy and the postpartum period.

Antenatal lifestyle advice for women who are overweight or obese: LIMIT randomised trial

OBJECTIVE

To determine the effect of antenatal dietary and lifestyle interventions on health outcomes in overweight and obese pregnant women.

DESIGN

Multicentre randomised trial. We utilised a central telephone randomisation server, with computer generated schedule, balanced variable blocks, and stratification for parity, body mass index (BMI) category, and hospital.

SETTING

Three public maternity hospitals across South Australia.

PARTICIPANTS

2212 women with a singleton pregnancy, between 10+0 and 20+0 weeks' gestation, and BMI ≥ 25.

INTERVENTIONS

1108 women were randomised to a comprehensive dietary and lifestyle intervention delivered by research staff; 1104 were randomised to standard care and received pregnancy care according to local guidelines, which did not include such information.

MAIN OUTCOME MEASURES

Incidence of infants born large for gestational age (birth weight ≥ 90th centile for gestation and sex). Prespecified secondary outcomes included birth weight >4000 g, hypertension, pre-eclampsia, and gestational diabetes. Analyses used intention to treat principles.

RESULTS

2152 women and 2142 liveborn infants were included in the analyses. The risk of the infant being large for gestational age was not significantly different in the two groups (lifestyle advice 203/1075 (19%) v standard care 224/1067 (21%); adjusted relative risk 0.90, 95% confidence interval 0.77 to 1.07; P=0.24). Infants born to women after lifestyle advice were significantly less likely to have birth weight above 4000 g (lifestyle advice 164/1075 (15%) v standard care 201/1067 (19%); 0.82, 0.68 to 0.99; number needed to treat (NNT) 28, 15 to 263; P=0.04). There were no differences in maternal pregnancy and birth outcomes between the two treatment groups.

CONCLUSIONS

For women who were overweight or obese, the antenatal lifestyle advice used in this study did not reduce the risk delivering a baby weighing above the 90th centile for gestational age and sex or improve maternal pregnancy and birth outcomes.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12607000161426).

Maternal Obesity and the First Birth: A Case for Targeted Contemporary Maternity Care

BACKGROUND: Obesity in childbearing women is associated with poorer pregnancy and birth outcomes, particularly caesarean section, compared with normal-weight women. The high caesarean section rate may reflect care and outcomes which occur at the time surrounding the first birth.

AIM: To describe the birth outcomes of extremely obese pregnant women (body mass index [BMI] of 40 or more) experiencing their first birth.

METHODS: Clinical audit was used to systematically review the care and birth outcomes of all extremely obese pregnant women experiencing their birth at one study site during a 2-year period in 2009 and 2010. Fifty participants birthed during the study period. Data were collected from booking to discharge from the maternity service and included variables such as model of care, number of appointments, and obstetric and neonatal outcomes. Descriptive statistics were used to describe and synthesize the data. Inferential statistics were used to draw inferences about the population.

RESULTS: Obese women rarely had contact with a midwife, except at booking, receiving a standard model of care provided by numerous caregivers, most often inexperienced medical staff. More than half of the obese women experienced a caesarean section (56%), 2.3 times that of normal-weight primiparous women who birthed at the study site during the same period (24.2%). This was despite 64% experiencing normal pregnancy free from any complication. For women who planned to labor, birth intervention including induction of labor, augmentation for slow labor, epidural, and continuous cardiotocography was high. Caesarean occurred most often for “failure to progress” and “failed induction.”

CONCLUSION: Clinical audit was useful in determining information, which suggests current maternity care provision is not meeting the needs of extremely obese women experiencing their first birth.

IMPLICATIONS FOR PRACTICE: The development of effective, targeted antenatal care designed to meet the needs of extremely obese women is recommended as are strategies to keep birth normal.

Reaching perinatal women online: the Healthy You, Healthy Baby website and app

Overwhelming evidence reveals the close link between unwarranted weight gain among childbearing women and childhood adiposity. Yet current barriers limit the capacity of perinatal health care providers (PHCPs) to offer healthy lifestyle counselling. In response, today's Internet savvy women are turning to online resources to access health information, with the potential of revolutionising health services by enabling PHCPs to guide women to appropriate online resources. This paper presents the findings of a project designed to develop an online resource to promote healthy lifestyles during the perinatal period. The methodology involved focus groups and interviews with perinatal women and PHCPs to determine what online information was needed, in what form, and how best it should be presented. The outcome was the development of the Healthy You, Healthy Baby website and smartphone app. This clinically-endorsed, interactive online resource provides perinatal women with a personalised tool to track their weight, diet, physical activity, emotional wellbeing, and sleep patterns based on the developmental stage of their child with links to quality-assured information. One year since the launch of the online resource, data indicates it provides a low-cost intervention delivered across most geographic and socioeconomic strata without additional demands on health service staff.

The views and attitudes of health professionals providing antenatal care to women with a high BMI: a qualitative research study

BACKGROUND

The prevalence of overweight and obesity is increasing amongst women of child bearing age. The objective of this study was to investigate the views and attitudes of providers of antenatal care for women who have a body mass index (BMI) of 30 kg/m(2) and over.

METHODS

A qualitative study using focus groups was undertaken within the department of obstetrics and gynaecology at a large teaching hospital in south-eastern Australia. Three focus group discussions were held. One with hospital midwives (n=10), one with continuity of care midwives (n=18) and one with obstetricians (n=5). Data were analysed using Interpretative Phenomenological Analysis (IPA).

FINDINGS

Six dominant themes emerged: (1) obesity puts the health of mothers, babies and health professionals at risk; (2) overweight and obesity has become the norm; (3) weighing women and advising about weight gain is out of fashion; (4) weight is a sensitive topic to discuss; (5) there are significant barriers to weight control in pregnancy; and (6) health professionals and women need to deal with maternal obesity. These themes are drawn together to form a model representing current health care issues for these women.

CONCLUSION

Health professionals, who have a high BMI, can find it difficult to discuss obesity during antenatal visits with obese women. Specialist dietary interventions and evidence based guidelines for working with child-bearing women is seen as a public health priority by health care professionals.

Trial for Reducing Weight Retention in New Mums: a randomised controlled trial evaluating a low intensity, postpartum weight management programme

BACKGROUND

Failure to return to pregnancy weight by 6 months postpartum is associated with long-term obesity, as well as adverse health outcomes. This research evaluated a postpartum weight management programme for women with a body mass index (BMI) > 25 kg m(-2) that combined behaviour change principles and a low-intensity delivery format with postpartum nutrition information.

METHODS

Women were randomised at 24-28 weeks to control (supported care; SC) or intervention (enhanced care; EC) groups, stratified by BMI cohort. At 36 weeks of gestation, SC women received a 'nutrition for breastfeeding' resource and EC women received a nutrition assessment and goal-setting session about post-natal nutrition, plus a 6-month correspondence intervention requiring return of self-monitoring sheets. Weight change, anthropometry, diet, physical activity, breastfeeding, fasting glucose and insulin measures were assessed at 6 weeks and 6 months postpartum.

RESULTS

Seventy-seven percent (40 EC and 41 SC) of the 105 women approached were recruited; 36 EC and 35 SC women received a programme and 66.7% and 48.6% completed the study, respectively. No significant differences were observed between any outcomes. Median [interquartile range (IQR)] weight change was EC: -1.1 (9.5) kg versus SC: -1.1 (7.5) kg (6 weeks to 6 months) and EC: +1.0 (8.7) kg versus SC: +2.3 (9) kg (prepregnancy to 6 months). Intervention women breastfed for half a month longer than control women (180 versus 164 days; P = 0.10). An average of 2.3 out of six activity sheets per participant was returned.

CONCLUSIONS

Despite low intervention engagement, the high retention rate suggests this remains an area of interest to women. Future strategies must facilitate women's engagement, be individually tailored, and include features that support behaviour change to decrease women's risk of chronic health issues.

Systematic review of lifestyle interventions to limit postpartum weight retention: implications for future opportunities to prevent maternal overweight and obesity following childbirth

Postpartum weight retention can predict future weight gain and long-term obesity. Moreover, failure to lose weight gained during pregnancy can lead to increased body mass index for subsequent pregnancies, increasing the risk of adverse maternal and foetal pregnancy outcomes. This systematic review evaluates the effectiveness of lifestyle interventions aimed at reducing postpartum weight retention. Seven electronic databases were searched for intervention studies and trials enrolling women with singleton pregnancies and published in English from January 1990 to October 2012. Studies were included when postpartum weight was a main outcome and when diet and/or exercise and/or weight monitoring were intervention components. No limitations were placed on age, body mass index or parity. Eleven studies were identified as eligible for inclusion in this review, of which 10 were randomized controlled trials. Seven studies were successful in decreasing postpartum weight retention, six of which included both dietary and physical activity components, incorporated via a range of methods and delivered by a variety of health practitioners. Few studies utilized modern technologies as alternatives to traditional face-to-face support and cost-effectiveness was not assessed in any of the studies. These results suggest that postpartum weight loss is achievable, which may form an important component of obesity prevention in mothers; however, the optimal setting, delivery, intervention length and recruitment approach remains unclear.

First trimester dietary intake, biochemical measures, and subsequent gestational hypertension among nulliparous women

INTRODUCTION

The purpose of this study was to evaluate the relationships between first-trimester dietary factors and biochemical measures and subsequent risk of gestational hypertension.

METHODS

This pilot study used a prospective design utilizing a convenience sample of nulliparous women enrolled at their first prenatal visit. A total of 57 women completed the study. Participants were divided into 2 groups for data analysis: normotensive pregnancy and gestational hypertension.

RESULTS

Nearly one-quarter of study participants (22.8%) developed gestational hypertension, of whom 84.6% had significant proteinuria meeting the criteria for preeclampsia. There were no significant differences in micronutrient or macronutrient dietary intakes between groups. Serum iron and zinc levels were lower for the gestational hypertension group compared with the normotensive pregnancy group (P ≤ .01). Low serum zinc levels were related to a risk of developing gestational hypertension (adjusted odds ratio, 0.930; 95% confidence interval, 0.872-0.992).

DISCUSSION

Ensuring adequate intake of zinc and monitoring serum zinc levels in nulliparous pregnant women may help to prevent or contribute to early detection of gestational hypertension.

Pregnant women's knowledge of weight, weight gain, complications of obesity and weight management strategies in pregnancy

Background

Obesity is increasingly common in the obstetric population. Maternal obesity and excess gestational weight gain (GWG) are associated with increased perinatal risk. There is limited published data demonstrating the level of pregnant women’s knowledge regarding these problems, their consequences and management strategies.

We aimed to assess the level of knowledge of pregnant women regarding: (i) their own weight and body mass index (BMI) category, (ii) awareness of guidelines for GWG, (iii) concordance of women’s own expectations with guidelines, (iv) knowledge of complications associated with excess GWG, and (v) knowledge of safe weight management strategies in pregnancy.

Methods

364 pregnant women from a single center university hospital antenatal clinic were interviewed by an obstetric registrar. The women in this convenience sample were asked to identify their weight category, their understanding of the complications of obesity and excessive GWG in pregnancy and safe and/or effective weight management strategies in pregnancy.

Results

Nearly half (47.8%) of the study population were overweight or obese. 74% of obese women underestimated their BMI category. 64% of obese women and 40% of overweight women overestimated their recommended GWG. Women’s knowledge of the specific risks associated with excess GWG or maternal obesity was poor. Women also reported many incorrect beliefs about safe weight management in pregnancy.

Conclusions

Many pregnant women have poor knowledge about obesity, GWG, their consequences and management strategies. Bridging this knowledge gap is an important step towards improving perinatal outcomes for all pregnant women, especially those who enter pregnancy overweight or obese.

Exercise in obese pregnant women: positive impacts and current perceptions

Overweight and obesity have significant implications during pregnancy and childbirth. The objective of this review was to provide a comprehensive overview of the effect of physical activity on pregnancy outcomes, the change of physical activity during pregnancy, and women's perception of being physically active during pregnancy, with a particular focus on women who are overweight or obese. Many studies have investigated the beneficial effect of exercise during pregnancy, including reduced risk of gestational diabetes, preeclampsia, and operative birth, in addition to improved cardiovascular function, overall fitness, psychological well-being, and mood stability. Benefits for the infant include reduced risks of prematurity and improved fetal growth, although there is more limited information about longer-term health benefits for both women and infants. The existing literature examining physical activity patterns during pregnancy has generally focused on women of all body mass index categories, consistently indicating a reduction in activity over the course of pregnancy. However, the available literature evaluating physical activity during pregnancy among women who are overweight or obese is more limited and contradictory. A number of studies identified barriers preventing women from being active during pregnancy, including pregnancy symptoms, lack of time, access to child care, and concerns about their safety and that of their unborn baby. Conversely, significant enablers included positive psychological feelings, family influence, and receiving advice from health professionals. Very few studies have provided insights about perceptions of being active during pregnancy in the overweight and obese population. There is a need for a detailed description of physical activity patterns during pregnancy in women who are overweight or obese, and more randomized trials evaluating exercise interventions for women who are overweight or obese, with a focus on clinical outcomes.

Female obesity: short- and long-term consequences on the offspring

The worldwide prevalence of obesity has risen over the past few decades and women are currently more likely than ever to enter pregnancy obese. Pre-pregnancy obesity and excessive gestational weight gain increase miscarriage rates and obstetric and neonatal complications, which result in a lower healthy live birth rate. In addition to its negative consequences for the mother, obesity has been shown to be an important risk factor for chronic illnesses, such as cardiovascular disease, metabolic syndrome and type 2 diabetes in the adolescence and adulthood of the offspring. Moreover, maternal obesity causes psychological problems, physical disabilities and higher healthcare costs. Fetal programming of metabolic function induced by obesity, through physiological and/or epigenetic mechanisms, may have an intergenerational effect and could, thus, perpetuate obesity in the next generation. In order to break this vicious circle and avoid serious short- and long-term negative outcomes for both mothers and fetuses, the prevention and adequate management of obesity and gestational weight gain are essential.

Primary prevention of gestational diabetes for women who are overweight and obese: a randomised controlled trial

BACKGROUND

Gestational Diabetes Mellitus (GDM) has well recognised adverse health implications for the mother and her newborn that are both short and long term. Obesity is a significant risk factor for developing GDM and the prevalence of obesity is increasing globally. It is a matter of public health importance that clinicians have evidence based strategies to inform practice and currently there is insufficient evidence regarding the impact of dietary and lifestyle interventions on improving maternal and newborn outcomes. The primary aim of this study is to measure the impact of a telephone based intervention that promotes positive lifestyle modifications on the incidence of GDM. Secondary aims include: the impact on gestational weight gain; large for gestational age babies; differences in blood glucose levels taken at the Oral Glucose Tolerance Test (OGTT) and selected factors relating to self-efficacy and psychological wellbeing.

METHOD/DESIGN

A randomised controlled trial (RCT) will be conducted involving pregnant women who are overweight (BMI >25 to 29.9 k/gm2) or obese (BMI >30 kgm/2), less than 14 weeks gestation and recruited from the Barwon South West region of Victoria, Australia. From recruitment until birth, women in the intervention group will receive a program informed by the Theory of Self-efficacy and employing Motivational Interviewing. Brief ( less than 5 minute) phone contact will alternate with a text message/email and will involve goal setting, behaviour change reinforcement with weekly weighing and charting, and the provision of health information. Those in the control group will receive usual care. Data for primary and secondary outcomes will be collected from medical record review and a questionnaire at 36 weeks gestation.

DISCUSSION

Evidence based strategies that reduce the incidence of GDM are a priority for contemporary maternity care. Changing health behaviours is a complex undertaking and trialling a composite intervention that can be adopted in various primary health settings is required so women can be accessed as early in pregnancy as possible. Using a sound theoretical base to inform such an intervention will add depth to our understanding of this approach and to the interpretation of results, contributing to the evidence base for practice and policy.

TRIAL REGISTRATION

This trial is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12613000125729.

The Maternal Obesity Management (MOM) Trial Protocol: a lifestyle intervention during pregnancy to minimize downstream obesity

BACKGROUND

Maternal obesity and/or high gestational weight gain (GWG) are associated with downstream child obesity. Pregnancy represents a critical period for prevention as women are highly motivated and more receptive to behavior change.

OBJECTIVE

This pilot study was developed to test the feasibility of intervening with the mother, specifically keeping her GWG within the Institute of Medicine (IOM) limits, with the intended target of preventing obesity in her child downstream. We are testing the practicality of delivering a structured physical activity and nutrition intervention to pregnant women during gestation and then following mom and baby to 24 months of age.

STUDY DESIGN

This study is a two-arm, parallel group, randomized controlled trial being conducted in Ottawa. Pregnant women, with pregravid BMI >18.5, between 12 and 20 weeks gestation are randomized to one of two groups: intervention (n=30) who receive the MOM trial Handbook (guide to healthy gestation) plus a structured physical activity and nutrition program, or a standard clinical care control group (n=30). The intervention lasts 25-28 weeks (6 months) depending on anticipated delivery date, with follow-up assessment on mother and child at 3, 6, 12 and 24 months post-delivery.

SIGNIFICANCE

Pregnancy, a critical time of growth, development and physiological change, provides an opportunity for early lifestyle intervention. The goal of identifying an effective lifestyle program for the gestational period that leads to healthy fetal development and subsequently normal weight offspring, less likely to develop obesity and its co-morbidities, is unique and could possibly attenuate the inter-generational cycle of obesity.

Developing a tool for obtaining maternal skinfold thickness measurements and assessing inter-observer variability among pregnant women who are overweight and obese

Background

It is estimated that between 34% and 50% of Australian women entering pregnancy are overweight and obese, which is associated with an increased risk in complications for both the woman and her infant. Current tools used in clinical and research practice for measuring body composition include body mass index (BMI), waist circumference and bioimpedance analysis. Not all of these measures are applicable for use during pregnancy due to a lack of differentiation between maternal and fetal contributions. While skinfold thickness measurement (SFTM) is increasingly being used in pregnancy, there is limited data and a lack of a standard tool for its use in overweight and obese pregnant women.

Methods

We developed a standard tool for evaluating SFTM among women with a BMI ≥ 25 kg/m². Forty-nine women were measured as part of a prospective cohort study nested within a multicentre randomised controlled trial (The LIMIT Randomised Controlled Trial). Two blinded observers each performed 2 skinfold measurements on the biceps, triceps and subscapular of each woman. Intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were used to analyse SFTM, body fat percentage (BF%) and inter-observer variability.

Results

The ICC for inter-observer variability in measurements were considered moderate for biceps SFTM (ICC = 0.56) and triceps SFTM (ICC = 0.51); good for subscapular SFTM (ICC = 0.71) and BF% (ICC = 0.74); and excellent for arm circumference (ICC = 0.97). The standard error of measurements ranged from 0.53 cm for arm circumference to 3.58 mm for the subscapular SFTM.

Conclusion

Our findings indicate that arm circumference and biceps, triceps and subscapular SFTM can be reliably obtained from overweight and obese pregnant women to calculate BF%, using multiple observers, and can be used in a research setting.

Trial registration

Australian and New Zealand Clinical Trials Registry ACTRN12607000161426

Risk factors for antepartum stillbirth and the influence of maternal age in New South Wales Australia: a population based study

Background

Maternal age is a known risk factor for stillbirth and delayed childbearing is a societal norm in developed country settings. The timing and reasons for age being a risk factor are less clear. This study aimed to document the gestational specific risk of maternal age throughout pregnancy and whether the underlying causes of stillbirth differ for older women.

Methods

Using linkage of state maternity and perinatal death data collections the authors assessed risk factors for antepartum stillbirth in New South Wales Australia for births between 2002 – 2006 (n = 327,690) using a Cox proportional hazards model. Gestational age specific risk was calculated for different maternal age groups. Deaths were classified according to the Perinatal Mortality Classifications of the Perinatal Society of Australia and New Zealand.

Results

Maternal age was a significant independent risk factor for antepartum stillbirth (35 – 39 years HR 1.4 95% CI 1.12 – 1.75; ≥ 40 years HR 2.41 95% CI 1.8 – 3.23). Other significant risk factors were smoking HR 1.82 (95% CI 1.56 –2.12) nulliparity HR 1.23 (95% CI 1.08 – 1.40), pre-existing hypertension HR 2.77 (95% CI 1.94 – 3.97) and pre-existing diabetes HR 2.65 (95% CI 1.63 – 4.32). For women aged 40 or over the risk of antepartum stillbirth beyond 40 weeks was 1 in 455 ongoing pregnancies compared with 1 in 1177 ongoing pregnancies for those under 40. This risk was increased in nulliparous women to 1 in 247 ongoing pregnancies. Unexplained stillbirths were the most common classification for all women, stillbirths classified as perinatal infection were more common in the women aged 40 or above.

Conclusions

Women aged 35 or older in a first pregnancy should be counselled regarding stillbirth risk at the end of pregnancy to assist with informed decision making regarding delivery. For women aged 40 or older in their first pregnancy it would be reasonable to offer induction of labour by 40 weeks gestation.

Nutritional approaches to breaking the intergenerational cycle of obesity

The link between poor maternal nutrition and an increased burden of disease in subsequent generations has been widely demonstrated in both human and animal studies. Historically, the nutritional challenges experienced by pregnant and lactating women were largely those of insufficient calories and severe micronutrient deficiencies. More recently, however, Western societies have been confronted with a new nutritional challenge; that of maternal obesity and excessive maternal intake of calories, fat, and sugar. Exposure of the developing fetus and infant to this obesogenic environment results in an increased risk of obesity and metabolic disease later in life. Furthermore, increased caloric, fat, and sugar intake can occur in conjunction with micronutrient deficiency, which may further exacerbate these programming effects. In light of the current epidemic of obesity and metabolic disease, attention has now turned to identifying nutritional interventions for breaking this intergenerational obesity cycle. In this review, we discuss the approaches that have been explored to date and highlight the need for further research.

The relative contribution of prepregnancy overweight and obesity, gestational weight gain, and IADPSG-defined gestational diabetes mellitus to fetal overgrowth

OBJECTIVE

The International Association of Diabetes in Pregnancy Study Groups (IADPSG) criteria for diagnosis of gestational diabetes mellitus (GDM) identifies women and infants at risk for adverse outcomes, which are also strongly associated with maternal overweight, obesity, and excess gestational weight gain.

RESEARCH DESIGN AND METHODS

We conducted a retrospective study of 9,835 women who delivered at ≥20 weeks' gestation; had a prenatal, 2-h, 75-g oral glucose tolerance test; and were not treated with diet, exercise, or antidiabetic medications during pregnancy. Women were classified as having GDM based on IADPSG criteria and were categorized into six mutually exclusive prepregnancy BMI/GDM groups: normal weight ± GDM, overweight ± GDM, and obese ± GDM.

RESULTS

Overall, 5,851 (59.5%) women were overweight or obese and 1,892 (19.2%) had GDM. Of those with GDM, 1,443 (76.3%) were overweight or obese. The prevalence of large-for-gestational-age (LGA) infants was significantly higher for overweight and obese women without GDM compared with their normal-weight counterparts. Among women without GDM, 21.6% of LGA infants were attributable to maternal overweight and obesity, and the combination of being overweight or obese and having GDM accounted for 23.3% of LGA infants. Increasing gestational weight gain was associated with a higher prevalence of LGA in all groups.

CONCLUSIONS

Prepregnancy overweight and obesity account for a high proportion of LGA, even in the absence of GDM. Interventions that focus on maternal overweight/obesity and gestational weight gain, regardless of GDM status, have the potential to reach far more women at risk for having an LGA infant.

Excess gestational weight gain: an exploration of midwives' views and practice

BACKGROUND

Excess gestational weight gain (GWG) can affect the immediate and long term health outcomes of mother and infant. Understanding health providers' views, attitudes and practices around GWG is crucial to assist in the development of practical, time efficient and cost effective ways of supporting health providers to promote healthy GWGs. This study aimed to explore midwives' views, attitudes and approaches to the assessment, management and promotion of healthy GWG and to investigate their views on optimal interventions.

METHODS

Midwives working in antenatal care were recruited from one rural and one urban Australian maternity hospital employing purposive sampling strategies to assess a range of practice areas. Face-to-face interviews were conducted with 15 experienced midwives using an interview guide and all interviews were digitally recorded, transcribed verbatim and analysed thematically.

RESULTS

Midwives interviewed exhibited a range of views, attitudes and practices related to GWG. Three dominant themes emerged. Overall GWG was given low priority for midwives working in the antenatal care service in both hospitals. In addition, the midwives were deeply concerned for the physical and psychological health of pregnant women and worried about perceived negative impacts of discussion about weight and related interventions with women. Finally, the midwives saw themselves as central in providing lifestyle behaviour education to pregnant women and identified opportunities for support to promote healthy GWG.

CONCLUSIONS

The findings indicate that planning and implementation of healthy GWG interventions are likely to be challenging because the factors impacting on midwives' engagement in the GWG arena are varied and complex. This study provides insights for guideline and intervention development for the promotion of healthy GWG.

The Relation between Early Pregnancy Anthropometric Indices among Primiparous Women and Macrosomia

INTRODUCTION

The prevalence of obesity is increasing in both developed and developing nations. Body mass index (BMI) is the most common index for obesity assessment and its relation with most complications among non-pregnant and pregnant women is known. However, no study has evaluated the relation between abdominal obesity and macrosomia among pregnant women.

METHODS

In this prospective study, anthropometric indices including weight, height, and waist circumference (WC) of 1140 nulliparous pregnant women during their first trimester of pregnancy (6(th)-10(th) weeks) were measured by the researcher. According to the classification of the World Health Organization, women with BMI > 25 kg/m(2) were considered as overweight or obese. Abdominal obesity was defined as WC ≥ 88 cm. Finally, mothers were followed up and fetal macrosomia was recorded in a checklist. Data was analyzed in SPSS15.

RESULTS

The results showed that 77.5% of women aged 20-35 years and 92.7% were housewives. The mean (SD) values of BMI and WC were 24.32 (4.08) kg/m(2) and 81.84 (9.25) cm, respectively. The prevalence of overweight (BMI = 25-29.9 kg/m(2)) and obesity (BMI > 29.9 kg/m) was 27.6% and 8.8%, respectively. Abdominal obesity based on WC was found in 34.8% of the subjects.

CONCLUSION

Findings of this study revealed obesity in over one third of nulliparous pregnant women during their first trimester. Moreover, the high prevalence of macrosomia, in these women confirmed the importance of maternal education about obesity-related complications in order to change their lifestyle and prevent obesity.

Prepregnancy maternal body mass index and preterm delivery

OBJECTIVE

The purpose of this study was to determine the influence of maternal prepregnancy body mass index on preterm delivery (PTD), controlling for health and lifestyle variables.

STUDY DESIGN

Prospective data were from 83,544 pregnancies in the Norwegian Mother and Child Cohort Study. PTD was divided into early PTD (22 + 0 to 31 + 6 weeks' gestation) and late PTD (32 + 0 to 36 + 6 weeks' gestation).

RESULTS

The overall prevalence of PTD was 5.1%. Increased body mass index was associated with an increased risk of PTD; adjusted odds ratio (aOR) ranged from 1.11 (95% confidence interval [CI], 1.03-1.20) for preobesity to 2.00 (95% CI, 1.48-2.71) for grade-III obesity in the group that included all PTD subgroups. Grade-III obese women had an increased risk of both early and late PTD: aOR, 3.24 (95% CI, 1.71-6.14) and 1.81 (95% CI, 1.29-2.54), respectively.

CONCLUSION

Prepregnancy maternal overweight increases the risk of both early and late PTD.

The effects of obesity on the first stage of labor

OBJECTIVE

To estimate the effects of obesity on the duration and progression of the first stage of labor in a predominantly obese population and estimate the dose-effect with increasing classes of obesity.

METHODS

We performed a retrospective cohort study of labor progression among 5,204 consecutive parturients with singleton term pregnancies (37 weeks of gestation or more) and vertex presentation who completed the first stage of labor. Two comparison groups were defined by body mass index (BMI) less than 30 (n=2,413) or 30 or more (n=2,791). Repeated-measures analysis with polynomial modeling was used to construct labor curves. The duration and progression among women with BMIs less than 30 and BMIs of 30 or more were compared in a multivariable interval-censored regression model adjusting for parity, type of labor onset, race, and birth weight more than 4,000 g.

RESULTS

The labor curves indicate longer duration and slower progression of the first stage of labor among women with BMIs of 30 or more for both nulliparous and multiparous women. Multivariable interval-censored regression analysis confirmed significantly longer duration (4-10 cm: 4.7 compared with 4.1 hours, P<.01) and slower progression of cervical dilation from 4 to 6 cm (2.2 compared with 1.9 hours, P<.01 with a range of 0.5-10.0 hours) among women with BMIs of 30 or more after adjusting for confounders.

CONCLUSION

The overall duration is longer and progression of the early part of the first stage of labor is slower in obese women. This suggests that obesity should be considered in defining norms for management of labor, particularly in the early part of the first stage.

Obesity and reproductive dysfunction in women

Overweight and obesity are significant and increasing health problems associated with increased risks of morbidity, quality of life, and metabolic and reproductive health consequences. In women, being overweight or obese is associated with impaired fertility and decreased chance of conception both in natural and assisted reproductive technology births. During pregnancy, overweight and obesity are associated with increased risk of adverse maternal and infant health outcomes. Attention to weight loss before conception may improve fertility and maternal and infant health outcomes during pregnancy.

Intergenerational cycle of obesity and diabetes: how can we reduce the burdens of these conditions on the health of future generations?

Prepregnancy overweight or obesity and excessive gestational weight gain have been associated with increased risk of maternal and neonatal complications. Moreover, offspring from obese women are more likely to develop obesity, diabetes mellitus, and cardiovascular diseases in their lifetime. Gestational diabetes mellitus (GDM) is one of the most common complications associated with obesity and appears to have a direct impact on the future metabolic health of the child. Fetal programming of metabolic function induced by obesity and GDM may have intergenerational effect and thus perpetuate the epidemic of cardiometabolic conditions. The present paper thus aims at discussing the impact of maternal obesity and GDM on the developmental programming of obesity and metabolic disorders in the offspring. The main interventions designed to reduce maternal obesity and GDM and their ability to break the vicious circle that perpetuates the transmission of obesity and metabolic conditions to the next generations are also addressed.

Limiting weight gain in overweight and obese women during pregnancy to improve health outcomes: the LIMIT randomised controlled trial

Background

Obesity is a significant global health problem, with the proportion of women entering pregnancy with a body mass index greater than or equal to 25 kg/m² approaching 50%. Obesity during pregnancy is associated with a well-recognised increased risk of adverse health outcomes both for the woman and her infant, however there is more limited information available regarding effective interventions to improve health outcomes.

The aims of this randomised controlled trial are to assess whether the implementation of a package of dietary and lifestyle advice to overweight and obese women during pregnancy to limit gestational weight gain is effective in improving maternal, fetal and infant health outcomes.

Methods/Design

Design: Multicentred randomised, controlled trial.

Inclusion Criteria: Women with a singleton, live gestation between 10⁺⁰-20⁺⁰ weeks who are obese or overweight (defined as body mass index greater than or equal to 25 kg/m²), at the first antenatal visit.

Trial Entry & Randomisation: Eligible, consenting women will be randomised between 10⁺⁰ and 20⁺⁰ weeks gestation using a central telephone randomisation service, and randomisation schedule prepared by non-clinical research staff with balanced variable blocks. Stratification will be according to maternal BMI at trial entry, parity, and centre where planned to give birth.

Treatment Schedules: Women randomised to the Dietary and Lifestyle Advice Group will receive a series of inputs from research assistants and research dietician to limit gestational weight gain, and will include a combination of dietary, exercise and behavioural strategies.

Women randomised to the Standard Care Group will continue to receive their pregnancy care according to local hospital guidelines, which does not currently include routine provision of dietary, lifestyle and behavioural advice.

Outcome assessors will be blinded to the allocated treatment group.

Primary Study Outcome: infant large for gestational age (defined as infant birth weight ≥ 90^th centile for gestational age).

Sample Size: 2,180 women to detect a 30% reduction in large for gestational age infants from 14.40% (p = 0.05, 80% power, two-tailed).

Discussion

This is a protocol for a randomised trial. The findings will contribute to the development of evidence based clinical practice guidelines.

Trial Registration

Australian and New Zealand Clinical Trials Registry ACTRN12607000161426