Elsevier

Midwifery

Volume 52, September 2017, Pages 64-70
Midwifery

Commentary
Preventing obesity across the preconception, pregnancy and postpartum cycle: Implementing research into practice

https://doi.org/10.1016/j.midw.2017.06.003Get rights and content

Introduction

Women of reproductive age are on an accelerated pathway to increased weight and obesity, underscored by increasing background weight gain in women aged 18–35 (Adamson et al., 2007). Critical high-risk windows include pregnancy and post-partum which exacerbate weight gain, contributing to adverse reproductive, metabolic and psychosocial sequelae (Fraser et al., 2011, Johnson et al., 2013) and presenting a major public health challenge. Women of reproductive age gain more weight annually than older women (Adamson et al., 2007) and weight gain is inversely proportional to body mass index (BMI) (Cameron et al., 2003) with lean women the highest gainers and 20% progressing to higher BMI categories within five years (Adamson et al., 2007, Ball et al., 2003). Risk of health complications increase exponentially with even small increases in weight, including Type 2 Diabetes (T2DM) from a BMI of 22 kg/m2 (Colditz et al., 1990) and cardiovascular disease risk increasing by 3% with each kilo gained (Willett et al., 1995).

In this age group, weight gain translates to both maternal, and subsequent generation, adverse health effects (Fig. 1). Preconception, women are a large, diverse population who do not identify themselves as a distinct high-risk group or at a specific life stage (Lewis et al., 2013, Finer and Henshaw, 2006). Coupled with limited research and awareness in this population, over 50% of women are falling pregnant overweight or obese (Trends in adult body-mass index in 200 countries from 1975 to 2014) (Fig. 1). Higher BMI prior to conception is an independent risk factor for adverse outcomes during pregnancy including hypertension, Gestational Diabetes Mellitus (GDM), preeclampsia, caesarean section and the delivery of a large-for-gestational-age infant (McIntyre et al., 2012, Nohr et al., 2008). During pregnancy, risk of excessive gestational weight gain (GWG) is high, with 50–60% of overweight and obese women gaining above international Institute Of Medicine recommendations (Rasmussen and Yaktine, 2009, Deputy et al., 2015, Harrison et al., 2012). Excessive GWG has major implications during pregnancy with every kilo gained above recommendations linked to ~10% increase in adverse outcomes (Cedergren, 2007), including foetal malformations, miscarriage, preeclampsia, gestational diabetes, labour complications and increased health care costs (Callaway et al., 2006, Guelinckx et al., 2008). Risks are exacerbated in the presence of pre-existing obesity. Following pregnancy women retain, on average, ~2–5 kg (Adamson et al., 2007, Rasmussen and Yaktine, 2009) with excessive GWG a strong predictor for future maternal obesity, irrespective of pre-pregnancy BMI (Amorim et al., 2007). Women who gain above recommendations have a 300% increased risk of obesity development within two decades (Fraser et al., 2011).

Offspring outcomes of obesity during pregnancy add to the burden, with inter-generational epigenetic effects fuelling the weight gain cycle. Children born to obese mothers are twice as likely to develop childhood obesity, independent of confounding factors including maternal age, race, parity, education and gestational weight gain and gender and birthweight of the child (Whitaker, 2004). Recent research in animal mice models demonstrates obesity and associated metabolic disturbances including insulin resistance and dyslipidaemia prior to conception, result in transgenerational changes to offspring skeletal muscle mitochondrial functioning as far are three subsequent generations via the female germline (Saben et al., 2016). Mitochondria are primarily involved in fuel metabolism and dysfunction is, in turn, linked to aberrant metabolic functioning, insulin resistance and potentially to predisposition of obesity (Turner and Robker, 2015). However, generational risks are not confined to obese mothers. Irrespective of obesity, excessive GWG is also an independent risk factor for future offspring obesity, with children 3 times more likely to develop obesity later in life (Yu et al., 2013). Previous reports suggest the highest risk is in children born to mothers with a healthy pre-pregnancy BMI (Sridhar et al., 2014).

Given the vital need to address and arrest the cycle of increasing weight gain, prevention is at the forefront of the international public health agenda, as highlighted by major organisations including World Health Organization, National Institutes of Health and key Government agencies (Teede et al., 2014, Obesity, 2004, Lumeng et al., 2015).

Pregnancy is a recognised teachable window with increased motivation towards healthy lifestyle behaviours to ensure positive pregnancy outcomes (Phelan, 2010). Together with the majority of women experiencing at least one pregnancy (Australian Social Trends, 2010) and 95% of pregnant women attending antenatal care regularly (Redshaw and Heikkila, 2010, Bergsjø, 2000), this provides an ideal platform to capitalise on a broad population regularly engaged with the healthcare system and with added potential for further reach of healthy lifestyle messages to children, partners and the wider family. Consequently, much of the research to date has focused on antenatal lifestyle intervention to prevent excessive weight gain, reduce postpartum retention and address obesity prevention. Conversely, there is a paucity of research in other critical windows including preconception and postpartum with key barriers including hard to capture populations, limited engagement opportunities and less connectedness with the healthcare system.

Several systematic reviews summarising lifestyle intervention in pregnancy show improvement in GWG and maternal outcomes. Meta-analysis of 7278 women found a reduction in GWG of 1.42 kg [95% CI: 0.95–1.89 kg] overall, compared to no intervention, as well as reduced risk of preeclampsia and shoulder dystocia, with a trend towards reduced GDM (Thangaratinam et al., 2012). There appears to be little impact on birth weight and foetal outcomes and a trend towards reduced large for gestational age babies (Thangaratinam et al., 2012). Weight gain monitoring can facilitate healthy GWG, however weight monitoring alone, without intervention, is ineffective (Jeffries et al., 2009, Harrison et al., 2014). Additionally, behavioural strategies such as motivational interviewing, as well as modern technology, appear to be important components of successful intervention programs (Thangaratinam et al., 2012, Muktabhant et al., 2012, Hill et al., 2013, van der Pligt et al., 2013). Alignment with, or integration into, routine antenatal care facilitates engagement and reduces attrition, as noted in our behavioural Healthy Lifestyle Program (HeLP-her) in high risk pregnancies (Harrison et al., 2013, Harrison et al., 2014). Longer-term, antenatal lifestyle intervention may have sustained effect, with data six years post pregnancy showing a 4 kg weight difference in favour of women receiving intervention compared to those who did not (Claesson et al., 2014), with further supporting longitudinal research required.

With evidence of antenatal lifestyle intervention now consolidated, including the largest meta-analyses of individual patient data of women receiving antenatal lifestyle intervention undertaken by the International Women in Pregnancy (iWIP) consortium (Ruifrok et al., 2014), it is now time to shift focus on otherwise isolated efficacy trials and accelerate action towards implementation research by understanding how to best adapt such studies into routine antenatal care (Peters et al., 2013). Development of implementation strategies are vital to capitalise on investment in efficacy studies, translate evidence to inform policy and practice (Peters et al., 2013) and deliver programs ready for scale-up to deliver broader public health impact.

Implementation research is the “study of methods to promote the systematic uptake of research findings and other evidence based practices into routine practice, and, hence, to improve the quality and effectiveness of health services.” (Eccles and Mittman, 2006, Bauer et al., 2015). This is crucial in the setting of increasing weight gain in reproductive aged women and excessive GWG where otherwise isolated efficacy trials demonstrate health improvement is achievable without adverse risks. Despite this, a penetration of these interventions into practice is limited and at a population level, are almost unnoticed.

Addressing implementation barriers is vital to improve translation and future scale-up in this area. Barriers exist across the spectrum of health care in women, staff and health systems, with no systematic approach to healthy lifestyle in pregnancy and gaps at all levels of the antenatal health care system. Barriers include misperceptions around weight among health professionals and women, with less than 18% of obese pregnant women perceiving they are obese (Shub et al., 2013). Health systems challenges include inadequate weight monitoring in routine care, misperceptions of the importance of the prevention of excess GWG and disparities in medically advised GWG targets. On survey analyses of practices within a large Australian teaching hospital, only 4% of obstetricians and midwives accurately identified IOM GWG recommendations, only 25–30% suggested weight targets; only 1% based targets on knowledge of IOM guidelines and ~70% reported inadequate education and training in lifestyle (Stewart et al., 2012). In our national midwifery survey, even with knowledge on optimal GWG, lifestyle advice was suboptimal. There is inadequate health professional training and staff time to support lifestyle change (Biro et al., 2013). Sociocultural challenges for health professionals and women are problematic and there are limited available resources. Education, support and evidence-based, accessible resources, developed through implementation research with stakeholder engagement are now needed. Enablers of excessive GWG prevention in pregnancy include existing health care systems for pregnancy care with a health care workforce in place. Our group and others have also shown strong engagement in antenatal care across different socioeconomic and disadvantaged groups including Indigenous and refugee women (Phelan et al., 2011, Arslan Özkan and Mete, 2010, Edvardsson et al., 2011) as well as the antenatal teachable moment.

We propose that the creation of knowledge does not, itself, lead to widespread implementation and positive impacts on health must be proactively implemented, translated and scaled into changes in practice and policy. This includes an iterative framework for research and evidence driven impact, as proposed here (Fig. 2), adapted from the Canadian knowledge to action process (Straus et al., 2009). Our framework includes 6 key steps summarised below:

Steps 1 & 2- Formative Research: engage stakeholders on practices, programs, policies to inform an evidence base on how to maximise reach, effectiveness and sustainability when scaled-up in the ‘real world’.

Step 2 – Knowledge Synthesis: synthesis of relevant guidelines and research evidence.

Step 3 – Knowledge Generation: is consolidated following steps 1 and 2.

Step 4 – Implementation Research: the planned use of strategies will transfer and scale up evidence-based approaches into practice in real-world settings following knowledge synthesis. Pilot testing of resource usefulness and systems approaches including work place culture change. Subsequently, it facilitates refinement and broader scale-up.

Step 5 – Dissemination and Scale-Up: The distribution of information and resources with the intent of spreading knowledge and promoting use of evidence-based interventions. This is needed to inform how to maximise reach, effectiveness and sustainability through the testing and use of strategies to facilitate transfer and scale up of evidence-based approaches into practice in real-world settings. Scale-up refers to the development of organisational capacity for sustained, widespread use and the evaluation and monitoring of uptake and rollout (Oldenburg and Absetz, 2011, Fixsen et al., 2005), primarily facilitated through Government and health service responsibility. Broader uptake can be maximised through national communication channels to reach health professionals and organisations wishing to change practice based on these learnings. Direct alignment with National/International priorities optimises Government engagement for policy development and funding.

Step 6 – Evaluation: Evaluation of program delivery as well as patient and system barriers and enablers that influence scale-up and sustainability using existing frameworks including REAIM to assess Reach, Effectiveness, Adoption, Implementation and Maintenance (Glasgow et al., 1999). Health and economic outcomes also require evaluation to evaluate long-term sustainability and continuous quality improvement.

Accelerating implementation research to translate research into practice in the setting of antenatal care requires key actions across all sectors. This includes Government, to facilitate policy development; health systems to implement models of antenatal care; care providers, to drive implementation; professional organisations, to develop and promote guidelines for delivery of interventions and the community to value and engage in interventions to prevent excess GWG. Here, we propose 6 key areas of action imperative to facilitate translation of research into practice underpinned by the Monash Centre for Health Research and Implementation (MCHRI) framework for research and evidence driven impact (Fig. 2).

To provide a uniform approach for the prevention of excess GWG that can be implemented universally, scoping of policies, practices and initiatives for management of GWG across settings would be beneficial and ideally would involve collaboration between Government policies. Engagement would include key stakeholders across Government, professional societies, health care practitioners, midwifery, allied health staff, researchers and community group members. These activities could identify barriers and enablers to inform implementation, resource and education requirements. Specialised focus groups for vulnerable populations where evidence is lacking, including culturally and linguistically diverse and Indigenous groups would provide culturally relevant information to these high-risk populations.

This formative research could then be used to inform a unique model of care ready for implementation. Resource development for training and implementation could also occur at this stage to enable broad up-take across varying settings.

With synthesis of the evidence of interventions to reduce excess GWG now consolidated (Teede et al., 2014, Ruifrok et al., 2014), focus needs to shift to the validation available guidelines related to GWG. Within developed countries, disparities exists in pre-existing guidelines for monitoring GWG and there are no universal guidelines for appropriate GWG. For example, while many developed countries endorse the United States Institute of Medicine (IOM) 2009 GWG guidelines (Rasmussen and Yaktine, 2009), including the US (Weight gain during pregnancy), Canada (Prenatal nutrition guidelines for health professionals, 2014) and Australia (Australian Health Ministers’ Advisory Council, 2012), others, including the United Kingdom, do not (Weight managment before, during and after pregnancy, 2010). Even within countries, there is ambiguity in guidelines for GWG monitoring, further contributing to inconsistencies in practice across antenatal settings. Within Australia for example, the Government Department of Health Clinical Practice Guidelines advise restriction on frequent antenatal weight monitoring, yet the Royal Australian and New Zealand College of Obstetrics and Gynaecology recommends “weight gain should be discussed and monitored” (Australian Health Ministers’ Advisory Council, 2012, The Royal Australian and New Zealand College of Obstetricians and Gynaecologists, 2013).

Development of universal guidelines would ideally include GWG recommendations across the spectrum of BMI categories and ethnicities according to evidence based findings as well as recommendations for the frequency of monitoring to optimise healthy lifestyle behaviours.

Implementation and evaluation research is fundamental to capitalise on knowledge synthesis with investment in efficacy studies to translate evidence into policy and practice (Peters et al., 2013) and deliver programs ready for local adaptation/scale-up for a broader public health impact. Despite this, a general lack of understanding combined with the ubiquitous challenges of implementing pragmatic trials in real life settings has delayed progress (Peters et al., 2013). Implementation research needs to comprise engagement and co-designed adaptations of evidenced based interventions is then needed. Cross-sector stakeholder engagement includes multi-sector Federal and State Government, Obstetric, Gynaecological and Midwifery professional organisations, allied health professionals, hospital management and consumer groups. Midwifery and medical staff training and up-skilling to address cultural barriers and knowledge gaps present around the management of excess GWG is vital. Even with knowledge on optimal GWG, research demonstrates advice on lifestyle behaviour change can remain suboptimal (Biro et al., 2013).

Implementation research on co-designed, adapted lifestyle interventions should occur in a series of antenatal care settings with differing practices to adapt, evaluate and refine evidence based models of care in real world settings targeting diverse population groups, as well as vulnerable groups. Practices consistent with implementation designs, including opt-out rather than opt-in engagement strategies to ensure all women attending the service are engaged. Low-intensity delivery that is generalisable to diverse population groups, that maintains some face-to-face delivery yet is supplemented by self-management tools/resources is imperative to enable sustainability within the healthy system. Evidence-based resources should target health professionals, consumers and health services to enable broad uptake with low staff skill requirements, limit direct delivery and reduce cost and clinical time constraints. Resources should include contemporary technology (m-health and e-health websites, live chat, SMS, phone apps (VanWormer et al., 2006)), designed for broad scale roll-out.

Include development of National/International Birth Registries. A birth registry would objectively measure trends in maternal BMI and the impact of maternal BMI and GWG as our key public health challenge in pregnancy. It will also inform adherence to GWG advice, allow quality benchmarking across institutions and populations and measure the impact of the national implementation and scale up program for healthy GWG. It would advance significantly on the current incomplete, inconsistent data collection, where cases are not identified outside institutional data sets, organisations are not identified to enable benchmarking and public health trends, areas of quality concern and the impact of practice change cannot be evaluated. Use of evidence based evaluation frameworks including RE-AIM are essential to optimise Reach, Efficacy, Adoption, Implementation, and Maintenance (Glasgow et al., 1999) as well as health economic cost effectiveness analysis is essential to monitor impact against cost.

A recent Cochrane Review revealed an absence of published research on preconception interventions on pregnancy outcomes in overweight and obese women (Opray et al., 2015). Another systematic review noted only two weight loss intervention studies in preconception (Forsum et al., 2013), with moderate changes in inter-pregnancy weight reducing health risks, including large for gestational age (LGA) infants and pre-eclampsia in overweight/obese women reported (Glazer et al., 2004). Authors urged further research, acknowledging women do not identifying themselves as “preconception” as a recruitment barrier. There are no published studies on effective preconception health promotion interventions focused on healthy lifestyle and prevention of maternal obesity. Clearly, effective preconception healthy lifestyle promotion strategies are vital to reduce overweight and obesity prior to, during, and indeed also after pregnancy.

However, given only 50% of pregnancies are planned and 50% are unplanned (Finer and Zolna, 2011), identifying and reaching reproductive aged women who will become pregnant, to promote healthy lifestyle habits, is highly challenging. Women often do not engage with the health system or their primary care physician for preconception advice as they are otherwise healthy. Consequently, preventive interventions prior to conception are difficult to perform, and public health strategies to improve lifestyle and counteract overweight and obesity in reproductive aged young women are vital (Forsum et al., 2013). These public health strategies should target women where they live, work and interact across a range of delivery mediums including media, social media, phone service, website, community centres, early learning/childcare centres, primary care hospitals and workplaces. Multifaceted health promotion should include social media, social marketing, a public health platform with key messages, education, and self-management resources for engagement, awareness-raising and education on preconception and postpartum health. Unlike the wealth of evidence outlined in pregnancy, in preconception health there is clear evidence that lifestyle change across domains such as smoking, alcohol, recreational drugs, vaccinations, folate and optimal diet weight and physical activity are beneficial. However unlike pregnancy we lack the avenues to identify, reach and engage women as well as evidence on efficacy of intervention or on implementation strategies for broader effectiveness and scale up. This is a challenge internationally. Research across the MCHRI framework (Fig. 2) is essential to yield public health benefit and to optimise health preconception for women and the next generation.

Postpartum and inter-conception provides an opportunity systematically follow up and support women with targeted interventions to reduce weight gain and enable optimal pre-conception health care, improving future health for women and their children. However, these services remain fragmented between obstetric and primary care and are under-utilised. Whilst post-partum care is accessed by the majority of women, around 40% of women do not access care and this is more likely in women with limited resources (Optimising postpartum care, 2016). Of women who do attend, half report not having their information needs met including around issues such as healthy eating and exercise (Declercq et al., 2013). There are clear opportunities to systematically plan post-partum care including early identification of care providers, clear objectives that address women's needs such as a reproductive life plan, a weight management plan and linking in with services for the inter-conception period.

Inter-conception programs to date have focussed on women at increased risk either through a personal history of adverse pregnancy outcomes or as being in a population identified as at higher risk due to socioeconomic disparity (Johnson et al., 2006). An example of the latter includes the Healthy Start program which supports a woman and her child for two years with most grantees using care co-ordination and case management to facilitate better service access and provision in improving inter-conception health (Badura et al., 2008). The interconception period is a health care area that merits a broad public health approach, targeted interventions where required, improved data on service utilisation and linkage and evaluation of projects in order to support effective models of care.

Overall, while lifestyle behaviours occur at the individual level and require intervention, ultimately, lifestyle interventions to address this public health crisis must include societal and environmental strategies to support individual behaviour and lifestyle change. This requires community engagement, and Government to drive the successful public health triad of education, incentives and enabling strategies and regulation, including of the food and beverage industry. These societal level changes are vital moving forward acknowledging that individual targeted lifestyle strategies alone will not be successful.

Section snippets

Conclusion

Women of reproductive age are a high risk group for accelerated weight gain and obesity. Critical windows, including preconception, pregnancy and postpartum exacerbate increasing background weight gain and drive health risk. Evidence synthesis demonstrates that antenatal lifestyle intervention effectively limits GWG and reduces maternal complications without adverse risk to foetal development or resultant birth weight. With an evidence base now established, it is imperative to capitalise on

Competing interests

The authors declare that they have no competing interests.

Acknowledgements

Cheryce Harrison is a National Heart Foundation Postdoctoral Research Fellow (100168) and Helena Teede is a NHMRC Practitioner Fellow.

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References (69)

  • K. Ball et al.

    Patterns and demographic predictors of 5-year weight chmage in a multi-ethnic cohort of men and women in Australia

    Public Health Nutrition

    (2003)
  • M.S. Bauer et al.

    An introduction to implementation science for the non-specialist

    BMC Psychology

    (2015)
  • P. Bergsjø

    What is the evidence for the role of antenatal care strategies in the reduction of maternal mortality and morbidity?

    Safe Motherhood Strategies: A Review of the Evidence

    (2000)
  • L.K. Callaway et al.

    The prevalence and impact of overweight and obesity in an Australian obstetric population

    Medical Journal of Australia

    (2006)
  • A.J. Cameron et al.

    Overweight and obesity in Australia: the 1999–2000 Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

    Medical Journal of Australia

    (2003)
  • M.I. Cedergren

    Optimal gestational weight gain for body mass index categories (see comment)

    Obstetrics Gynecology

    (2007)
  • I.M. Claesson et al.

    Weight six years after childbirth: a follow-up of obese women in a weight-gain restriction programmme

    Midwifery

    (2014)
  • G.A. Colditz et al.

    Weight as a risk factor for clinical diabetes in women

    American Journal of Epidemiology

    (1990)
  • E.R. Declercq et al.

    Listening to Mothers III: new Mothers Speak Out. Report of National Surveys of Women's Childbearing Experiences Conducted October – December 2012 and January – April 2013

    (2013)
  • N. Deputy et al.

    Gestational weight gain - United States, 2012 and 2013

    MMWR Morbidity and Mortality Weekly Report

    (2015)
  • P. van der Pligt et al.

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

    Obesity Reviews

    (2013)
  • M.P. Eccles et al.

    . Welcome to implementation science

    Implementation Science

    (2006)
  • K. Edvardsson et al.

    Giving offspring a healthy start: parents' experiences of health promotion and lifestyle change during pregnancy and early parenthood

    BMC Public Health

    (2011)
  • L. Finer et al.

    Disparities in rates of unintended pregnancy in the United States, 1994 and 2001

    Perspectives on Sexual and Reproductive Health

    (2006)
  • D. Fixsen et al.

    Implementation Research: A Synthesis of the Literature

    (2005)
  • E. Forsum et al.

    Weight loss before conception: a systematic literature review

    Food Nutrition Research

    (2013)
  • A. Fraser et al.

    Associations of gestational weight gain with maternal body mass index, waist circumference, and blood pressure measured 16 years after pregnancy: the Avon Longitudinal Study of parents and children

    Obstetrical & Gynecological Survey

    (2011)
  • R. Glasgow et al.

    Evaluating the public health impact of health promotion interventions: the RE-AIM framework

    American Journal of Public Health

    (1999)
  • N.L. Glazer et al.

    Weight change and the risk of gestational diabetes in obese women

    Epidemiology

    (2004)
  • I. Guelinckx et al.

    Maternal obesity: pregnancy complications, gestational weight gain and nutrition

    Obesity Reviews

    (2008)
  • C. Harrison et al.

    Understanding health behaviours in a cohort of pregnant women at risk of gestational diabetes mellitus: an observational study

    BJOG: An International Journal of Obstetrics & Gynaecology

    (2012)
  • C. Harrison et al.

    Optimizing healthy gestational weight gain in women at high risk of gestational diabetes: a randomized controlled trial

    Obesity

    (2013)
  • C. Harrison et al.

    Limiting postpartum weight retention through early antenatal intervention: the HeLP-her randomised controlled trial

    International Journal of Behavioral Nutrition and Physical Activity

    (2014)
  • C.L. Harrison et al.

    How effective is self-weighing in the setting of a lifestyle intervention to reduce gestational weight gain and postpartum weight retention?

    ANZJOG

    (2014)
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