Researchers’ position statement on tackling obesity in pregnancy: the International Weight Management in Pregnancy (i-WIP) collaboration pleads for public health intervention

Maternal overweight and obesity during pregnancy: strategies to improve outcomes for women, babies, and children

INTRODUCTION

Women with overweight and obesity, and their children, are at increased risk of adverse pregnancy, birth, and longer term health outcomes, believed to be compounded by excessive gestational weight gain (GWG). Research to date has focused on interventions to reduce excessive GWG through changes to maternal diet and/or lifestyle.

AREAS COVERED

Current clinical recommendations for GWG vary according to a woman's early pregnancy body mass index, based on assumptions that associations between GWG and adverse pregnancy outcomes are causal in nature, and modifiable. While there are small differences in GWG following pregnancy interventions, there is little evidence for clinically relevant effects on pregnancy, birth, and longer term childhood outcomes. This review considers interventional studies targeting women with overweight or obesity to reduce GWG in an effort to improve maternal and infant health, and the current evidence for interventions prior to conception.

EXPERT OPINION

GWG is not modifiable via diet and lifestyle change, and continued efforts to find the 'right' intervention for women with overweight and obesity during pregnancy are unjustified. Researchers should focus on gathering evidence for interventions prior to pregnancy to optimize maternal health and weight to improve pregnancy, birth, and longer term health outcomes associated with obesity.

Preventive Counseling in Routine Prenatal Care-A Qualitative Study of Pregnant Women's Perspectives on a Lifestyle Intervention, Contrasted with the Experiences of Healthcare Providers

Maternal lifestyle during pregnancy and excessive gestational weight gain can influence maternal and infant short and long-term health. As part of the GeMuKi intervention, gynecologists and midwives provide lifestyle counseling to pregnant women during routine check-up visits. This study aims to understand the needs and experiences of participating pregnant women and to what extent their perspectives correspond to the experiences of healthcare providers. Semi-structured interviews were conducted with 12 pregnant women and 13 multi-professional healthcare providers, and were analyzed using qualitative content analysis. All interviewees rated routine check-up visits as a good setting in which to focus on lifestyle topics. Women in their first pregnancies had a great need to talk about lifestyle topics. None of the participants were aware of the link between gestational weight gain and maternal and infant health. The healthcare providers interviewed attributed varying relevance regarding the issue of weight gain and, accordingly, provided inconsistent counseling. The pregnant women expressed dissatisfaction regarding the multi-professional collaboration. The results demonstrate a need for strategies to improve multi-professional collaboration. In addition, health care providers should be trained to use sensitive techniques to inform pregnant women about the link between gestational weight gain and maternal and infant health.

Effectiveness of a Brief Lifestyle Intervention in the Prenatal Care Setting to Prevent Excessive Gestational Weight Gain and Improve Maternal and Infant Health Outcomes

Research on perinatal programming shows that excessive gestational weight gain (GWG) increases the risk of overweight and obesity later in a child’s life and contributes to maternal weight retention and elevated risks of obstetrical complications. This study examined the effectiveness of a brief lifestyle intervention in the prenatal care setting, compared to routine prenatal care, in preventing excessive GWG as well as adverse maternal and infant health outcomes. The GeMuKi study was designed as a cluster RCT using a hybrid effectiveness implementation design and was conducted in the prenatal care setting in Germany. A total of 1466 pregnant women were recruited. Pregnant women in intervention regions received up to six brief counseling sessions on lifestyle topics (e.g., physical activity, nutrition, drug use). Data on GWG and maternal and infant outcomes were entered into a digital data platform by the respective healthcare providers. The intervention resulted in a significant reduction in the proportion of women with excessive GWG (OR = 0.76, 95% CI (0.60 to 0.96), p = 0.024). Gestational weight gain in the intervention group was reduced by 1 kg (95% CI (−1.56 to −0.38), p < 0.001). No evidence of intervention effects on pregnancy, birth, or neonatal outcomes was found.

ENDOCRINOLOGY IN PREGNANCY: Targeting metabolic health promotion to optimise maternal and offspring health

There is an increase in maternal metabolic burden due to the rise in pregnancies complicated by obesity, gestational diabetes, type 2 diabetes and polycystic ovary syndrome. Metabolic dysfunction during pregnancy is associated with increased risks of long-term morbidity and mortality for women and their offspring. Lifestyle interventions in pregnancy in women at risk of metabolic dysfunction have demonstrated short-term improvements such as reduced gestational weight gain and lowered risk of gestational diabetes. It is not known whether these interventions lead to sustained improvements in the metabolic health of the mother and baby. Pharmacological interventions have also shown benefits for the mother and baby in pregnancy, including improvements in glycaemic control, reduction in gestational weight gain and reduction in large for gestational age infants; however, there remains uncertainty over long-term outcomes for mother and child. Existing studies on interventions targeting metabolic health are limited to selected populations in the preconception and postpartum periods and lack follow-up beyond delivery of the intervention. The COVID-19 pandemic has refocused our attention on the effects of maternal metabolic ill-health that play a role in contributing to premature morbidity and mortality. There is an urgent need for strategies to accurately identify the growing number of women and offspring at risk of long-term adverse metabolic health. Strategies which focus on early identification and risk stratification using individualised risk scores in the pre and inter-conception periods must take priority if we are to target and improve the metabolic health of women and their offspring who are at highest risk.

Creating Healthy Change in the Preconception Period for Women with Overweight or Obesity: A Qualitative Study Using the Information-Motivation-Behavioural Skills Model

Worldwide, half of women begin a pregnancy with overweight or obesity, which increases the risk of pregnancy and birth complications and adversely affects the lifelong health of the offspring. In order for metabolic changes to influence the gestational environment, research suggests that weight loss should take place before conception. This study aimed to understand women’s emotional and social contexts, knowledge, motivations, skills and self-efficacy in making healthy change. Semi-structured interviews conducted with twenty-three women with overweight or obesity, informed by the Information–Motivation–Behavioural Skills (IMB) model, were analysed using reflexive thematic analysis. Information-related themes identified included poor health risk knowledge, healthy food decisions and health versus convenience. The Motivation themes comprised taking responsibility, flexible options, social expectations, interpersonal challenges and accountability. Behavioural Skills entailed themes such as the mental battle, time management, self-care and inspiration. An environmental factor was identified in affordability—limiting access to healthier alternatives. Women wanted simple, flexible options that considered family commitments, time and budgetary constraints. Unprompted, several mentioned the importance of psychological support in managing setbacks, stress and maintaining motivation. Strategies for enhancing self-efficacy and motivational support are required to enable longstanding health behaviour change. Findings will inform intervention mapping development of an eHealth solution for women preconception.

Reappraisal of Gestational Weight Gain Recommendations in Obese Pregnant Women: A Population-Based Study of 337,590 Births

BACKGROUND AND OBJECTIVE

Maternal obesity is an epidemic health problem that is aggravated by excessive gestational weight gain (GWG) and postpartum weight retention. Current US Institute of Medicine (now US National Academy of Medicine) guidelines (2009) for GWG need to be evaluated against the current rise in obesity in the general and pregnant population. We wanted to study the relation between GWG and pregnancy and birth outcomes and to relate this to the current recommendations for GWG.

METHODS

Population-based study. We performed an epidemiological analysis in a cohort of Belgian pregnant women with singleton live births at term (≥37 weeks) between 2009 and 2014 (n = 337,590). Logistic regression was used to determine the optimal GWG in relation to relevant pregnancy and birth outcomes.

RESULTS

The prevalence of maternal obesity significantly increased from 10.3% in 2009 to 11.4% in 2014. The mean (SD) body mass index at the start of the pregnancy significantly increased from 23.9 (4.5) in 2009 to 24.2 (4.6) in 2014. Excessive GWG was frequent, especially in overweight (56.8%) and obese (52.9%) pregnant women. In the logistic regression model, the amount of GWG associated with the lowest incidence of both large-for-gestational-age and small-for-gestational-age infants was 21 kg in underweight women, 14 kg in normal weight, 8 kg in overweight, 0 kg in obese class I, -4 kg in obese class II and -5 kg in obese class III.

CONCLUSION

The prevalence of maternal obesity has risen in Belgium between 2009 and 2014. Current GWG guidelines, based on historic observational data, are probably too liberal for class II and III obese women in which better outcomes are being predicted for lower weight gain than recommended.

Effects of antenatal diet and physical activity on maternal and fetal outcomes: individual patient data meta-analysis and health economic evaluation

BACKGROUND

Diet- and physical activity-based interventions in pregnancy have the potential to alter maternal and child outcomes.

OBJECTIVES

To assess whether or not the effects of diet and lifestyle interventions vary in subgroups of women, based on maternal body mass index (BMI), age, parity, Caucasian ethnicity and underlying medical condition(s), by undertaking an individual patient data (IPD) meta-analysis. We also evaluated the association of gestational weight gain (GWG) with adverse pregnancy outcomes and assessed the cost-effectiveness of the interventions.

DATA SOURCES

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects and Health Technology Assessment database were searched from October 2013 to March 2015 (to update a previous search).

REVIEW METHODS

Researchers from the International Weight Management in Pregnancy Collaborative Network shared the primary data. For each intervention type and outcome, we performed a two-step IPD random-effects meta-analysis, for all women (except underweight) combined and for each subgroup of interest, to obtain summary estimates of effects and 95% confidence intervals (CIs), and synthesised the differences in effects between subgroups. In the first stage, we fitted a linear regression adjusted for baseline (for continuous outcomes) or a logistic regression model (for binary outcomes) in each study separately; estimates were combined across studies using random-effects meta-analysis models. We quantified the relationship between weight gain and complications, and undertook a decision-analytic model-based economic evaluation to assess the cost-effectiveness of the interventions.

RESULTS

Diet and lifestyle interventions reduced GWG by an average of 0.70 kg (95% CI -0.92 to -0.48 kg; 33 studies, 9320 women). The effects on composite maternal outcome [summary odds ratio (OR) 0.90, 95% CI 0.79 to 1.03; 24 studies, 8852 women] and composite fetal/neonatal outcome (summary OR 0.94, 95% CI 0.83 to 1.08; 18 studies, 7981 women) were not significant. The effect did not vary with baseline BMI, age, ethnicity, parity or underlying medical conditions for GWG, and composite maternal and fetal outcomes. Lifestyle interventions reduce Caesarean sections (OR 0.91, 95% CI 0.83 to 0.99), but not other individual maternal outcomes such as gestational diabetes mellitus (OR 0.89, 95% CI 0.72 to 1.10), pre-eclampsia or pregnancy-induced hypertension (OR 0.95, 95% CI 0.78 to 1.16) and preterm birth (OR 0.94, 95% CI 0.78 to 1.13). There was no significant effect on fetal outcomes. The interventions were not cost-effective. GWG, including adherence to the Institute of Medicine-recommended targets, was not associated with a reduction in complications. Predictors of GWG were maternal age (summary estimate -0.10 kg, 95% CI -0.14 to -0.06 kg) and multiparity (summary estimate -0.73 kg, 95% CI -1.24 to -0.23 kg).

LIMITATIONS

The findings were limited by the lack of standardisation in the components of intervention, residual heterogeneity in effects across studies for most analyses and the unavailability of IPD in some studies.

CONCLUSION

Diet and lifestyle interventions in pregnancy are clinically effective in reducing GWG irrespective of risk factors, with no effects on composite maternal and fetal outcomes.

FUTURE WORK

The differential effects of lifestyle interventions on individual pregnancy outcomes need evaluation.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013003804.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Lower education predicts poor response to dietary intervention in pregnancy, regardless of neighbourhood affluence: secondary analysis from the ROLO randomised control trial

Objective

To determine if response to a low glycaemic index (GI) dietary intervention, measured by changes in dietary intake and gestational weight gain, differed across women of varying socio-economic status (SES).

Design

Secondary data analysis of the ROLO randomised control trial. The intervention consisted of a two-hour low-GI dietary education session in early pregnancy. Change in GI was measured using 3 d food diaries pre- and post-intervention. Gestational weight gain was categorised as per the 2009 Institute of Medicine guidelines. SES was measured using education and neighbourhood deprivation.

Setting

The National Maternity Hospital, Dublin, Ireland.

Subjects

Women (n 625) recruited to the ROLO randomised control trial.

Results

The intervention significantly reduced GI and excess gestational weight gain (EGWG) among women with third level education residing in both disadvantaged (GI, mean (sd), intervention v. control: −3·30 (5·15) v. −0·32 (4·22), P=0·024; EGWG, n (%), intervention v. control: 7 (33·6) v. 22 (67·9); P=0·022) and advantaged areas (GI: −1·13 (3·88) v. 0·06 (3·75), P=0·020; EGWG: 41 (34·1) v. 58 (52·6); P=0·006). Neither GI nor gestational weight gain differed between the intervention and control group among women with less than third level education, regardless of neighbourhood deprivation.

Conclusions

A single dietary education session was not effective in reducing GI or gestational weight gain among less educated women. Multifaceted, appropriate and practical approaches are required in pregnancy interventions to improve pregnancy outcomes for less educated women.

What characteristics of nutrition and physical activity interventions are key to effectively reducing weight gain in obese or overweight pregnant women? A systematic review and meta-analysis

Lifestyle interventions targeting gestational weight gain (GWG) report varying degrees of success. To better understand factors influencing efficacy, we reviewed randomized trials specifically among obese and overweight pregnant women.

METHODS

We conducted a systematic review and a meta-analysis of 32 studies with a pooled population of 5,869 overweight or obese pregnant women. Random effects models were fit to compute the weighted mean difference (WMD) in GWG between groups across studies. Subgroup analyses were conducted to compare intervention efficacy in overweight vs. obese pregnant women, and interventions delivered by prenatal care providers (PCPs) vs. non-PCPs during pregnancy. Moderator analyses ensured.

RESULTS

Nine (28%) of 32 studies reported significant reductions in GWG in response to intervention. Of these, six (66%) of nine were delivered by PCPs. Overall, the WMD in GWG was -1.71 (95% confidence interval [CI]: -2.55, -0.86) kg. However, interventions delivered by PCPs yielded a significantly greater reduction in GWG compared to interventions delivered by non-PCPs (WMD = -3.88 kg; 95% CI: -7.01, -0.75 vs. -0.80 kg; 95% CI: -1.32, -0.28; p for difference = 0.005).

CONCLUSION

When PCPs counsel nutrition and physical activity, obese and overweight pregnant women have greater success meeting GWG targets and may be more motivated to modify their behaviour than with other modes of intervention deliveries.

Maternal obesity in Europe: where do we stand and how to move forward?: A scientific paper commissioned by the European Board and College of Obstetrics and Gynaecology (EBCOG)

Paralleling the global epidemic of obesity figures in the general population, the incidence of maternal obesity (BMI>30kg/m(2) at the start of pregnancy) has been rising over the last world. While most European countries do not systematically report obesity figures in their pregnant population, the prevalence of maternal obesity varies from 7 to 25% and seems strongly related to social and educational inequalities. Obesity during pregnancy represents an important preventable risk factor for adverse pregnancy outcomes and is associated with negative long-term health outcomes for both mothers and offspring. These effects are often aggravated by the high incidence of abnormal glucose tolerance and excessive gestational weight gain found in this group. The main controversies around the management of the obese pregnant women are related to (1) the value of repeated weighing during pregnancy, (2) the optimal gestational weight gain to advise and the lifestyle messages to deliver in order to achieve this, (3) the optimal strategy and timing of screening for gestational diabetes (GDM) and (4) the optimal timing and mode of delivery. These controversies are reviewed in this review, with the exception of screening for gestational diabetes that is discussed extensively elsewhere in this issue (Benhalima et al.). An agenda for research is proposed with the hope that it will catch the attention of policy-makers and funders and ultimately lead to the development of European-wide evidence-based guidelines for clinicians.