Variations in reporting of outcomes in randomized trials on diet and physical activity in pregnancy: A systematic review

Addressing the gaps in nutritional care before and during pregnancy

The present paper outlines current issues in the nutritional care of women during pregnancy and potential resources to address them. Globally, overnutrition, undernutrition and nutritional imbalances are widespread among women of reproductive age; increasing the risk of pregnancy complications and non-communicable diseases in both mothers and their children. Most women do not meet dietary guidelines for pregnancy. The World Health Organisation (WHO) recommends nutrition and weight counselling during pregnancy for all women. However, clinical practices focusing on nutrition vary and there is no consensus on which outcomes are most important for pregnancy nutrition interventions, with little consideration for the 'patient voice'. The International Federation of Gynaecology and Obstetrics (FIGO) nutrition checklist is a clinical practice tool that is available for healthcare professionals that will address this issue. The pregnancy nutrition core outcome set will also support advancement of antenatal nutrition by identifying the most critical nutrition-related outcomes from the perspective of healthcare professionals, researchers and women with experience of pregnancy. While poor nutrition can result in adverse outcomes across women of all weight categories, those with obesity may require specialist care to reduce their risk. Obesity is a chronic, progressive, relapsing disease that has high individual variability in its prognosis. The use of obesity staging systems, which consider mental, physical and functional health, can stratify individuals into risk categories and aid in treatment prioritisation in pregnancy. As the prevalence of obesity continues to rise, an obesity staging approach may support clinicians, especially those in limited resource settings.

Effects on the maternal-fetal health outcomes of various physical activity types in healthy pregnant women. A systematic review and meta-analysis

BACKGROUND

Physical activity (PA) promotes health in pregnancy.

OBJECTIVE

To collate the recent randomized controlled trial (RCT) on the effects of various types of PA during pregnancy on maternal-fetal health outcomes, among healthy mothers, and to report the variability in the outcomes reported.

SEARCH STRATEGY

Registered in PROSPERO (CRD42019143522). Systematic search conducted in EMBASE, CENTRAL, MEDLINE and CINAHL, from 2015-2020.

SELECTION CRITERIA

RCT examining PA interventions and maternal-fetal outcomes.

DATA COLLECTION AND ANALYSIS

Were independently extracted by two reviewers. Quality of studies was assessed with Cochrane Collaboration's risk of bias tool.

RESULTS

37 studies (6857 women) were included. PA had a protective effect on gestational weight gain (overall SMD -0.32, 95 % CI -0.46, -0.17, I² 77 %; supervised exercise SMD -0.15, 95 % CI -0.28, -0.02, I² 51 %; static cycling SMD -0.32, 95 % CI -0.59, -0.05; I² 49 %), gestational diabetes (overall OR 0.65, 95 % CI: 0.43, 0.98, I² 48 %), and hypertensive disorders (overall OR 0.51, 95 % CI: 0.31, 0.83, I² 0%).

CONCLUSIONS

PA in pregnancy had a preventive effect on weight gain, gestational diabetes, and hypertensive disorders. Supervised exercise and static cycling had a protective effect on gestational weight gain. Variation in outcomes reported suggest establishing a core outcome set.

Variations in long-term outcome reporting among offspring followed up after lifestyle interventions in pregnancy: a systematic review

Background Mothers and their offspring may benefit from lifestyle interventions during pregnancy. We systematically reviewed the literature to map and evaluate the quality of long-term offspring outcomes in follow-up cohorts of randomised controlled trials (RCTs). Methods We searched MEDLINE, EMBASE, CINAHL, Database of Abstracts of Reviews of Effects and Cochrane Central (until March 2019) for all RCTs evaluating any lifestyle (diet or exercise) intervention during pregnancy and their follow-up cohorts. Two reviews evaluated the extracted outcomes using two standardised assessment tools, one for quality of reporting (score range 0-6) and another for the variation in outcome selection. We extracted data in duplicate and reported using natural frequencies, medians, ranges, means and standard deviation (SD). Results We captured 30 long-term offspring outcomes reported in six articles (four studies). Offspring anthropometric measurements were the most commonly reported outcomes. There was a large variation in the measurement tools used. The mean overall quality score for outcome reporting was 3.33 (SD 1.24), with poor reporting of secondary outcomes and limited justification for the choice of the reported outcomes. Most studies showed selective reporting for both their primary and secondary outcomes. Conclusion The quality of reporting for long-term offspring outcomes following lifestyle interventions in pregnancy is varied with evidence of selective outcome reporting. Developing a core outcome set will help to reduce the variations in outcome reporting to optimise future research.

Effectiveness of physical activity interventions for overweight and obesity during pregnancy: a systematic review of the content of behaviour change interventions

BACKGROUND

Behaviour change techniques (BCTs) employed within PA intervention for pregnant women with a healthy body mass index (BMI) have been previously identified, however, these BCTS may differ for other weight profiles during pregnancy. The aim of this current review was to identify and summarise the evidence for effectiveness of PA interventions on PA levels for pregnant women with overweight and obesity, with an emphasis on the BCTs employed.

METHODS

A systematic review and meta-analysis of PA intervention studies using the PRISMA statement was conducted. Searches were conducted of eight databases in January 2019. Strict inclusion/exclusion criteria were employed. The validity of each included study was assessed using the Cochrane Collaboration's tool for assessing risk of bias. The primary outcome measure was change in PA levels, subjectively or objectively measured, with physical fitness as a secondary outcome. All intervention descriptions were double coded by two authors using Michie's et al's BCT taxonomy V1. Meta-analyses using random effect models assessed the intervention effects on PA. Other PA outcomes were summarised in a narrative synthesis.

RESULTS

From 8389 studies, 19 met the inclusion criteria 13 of which were suitable for inclusion in a meta-analysis. The remaining 6 studies were described narratively due to insufficient data and different outcome measures reported. In the meta-analysis, comparing interventions to a control group, significant increases were found in the intervention group for metabolic equivalent (SMD 0.39 [0.14, 0.64], Z = 3.08 P = 0.002) and physical fitness (VO₂ max) (SMD 0.55 [0.34, 0.75], Z = 5.20 P = < 0.001). Of the other six, five studies reported an increase in PA for the intervention group versus the control with the other study reporting a significant decrease for women in their 3rd trimester (p = 0.002). 'Self-monitoring of behaviour' was the most frequently used BCTs (76.5%), with 'social support' being newly identified for this pregnant population with overweight or obesity.

CONCLUSIONS

This review identified a slight increase in PA for pregnant women with overweight and obesity participating in interventions. However, due to the high risk of bias of the included studies, the results should be interpreted with caution. PA measures should be carefully selected so that studies can be meaningfully compared and standardised taxonomies should be used so that BCTs can be accurately assessed.

PREgnancy Nutrition: A protocol for the development of a Core Outcome Set (PRENCOS)

OBJECTIVE

To develop a Core Outcome Set (COS) for pregnancy nutrition research that is relevant to varied stakeholders and resource settings.

METHODS

This study has three distinct phases. The first phase involves generating a list of outcomes for consideration for the COS. This includes a systematic review of studies evaluating nutrition during pregnancy where all outcomes reported in relevant literature will be extracted. Qualitative interviews with currently or previously pregnant women will also be conducted. This step will supplement the findings of the systematic review by identifying additional outcomes of importance to this stakeholder group. In the second phase of the study, healthcare professionals, researchers, and mothers from various international resource settings will be invited to participate in a two-round modified Delphi survey. The aim of the survey is to gain consensus on which outcomes are most important to include in the COS. Finally, a face-face consensus meeting will be held with a select group of participants to finalize the COS.

CONCLUSION

This COS will support standardization of outcome reporting in pregnancy nutrition research and ensure that selected outcomes are considered important by a variety of stakeholders. This will enhance the evidence behind nutrition interventions in pregnancy to improve outcomes for pregnant women.

In Overweight or Obese Pregnant Women, Maternal Dietary Factors are not Associated with Fetal Growth and Adiposity

The aim of our study was to evaluate associations between maternal dietary factors and fetal growth and adiposity in overweight and obese women. Women randomised to the ‘Standard Care’ group of the LIMIT trial were included. Maternal dietary factors including Healthy Eating Index, total energy, fat, carbohydrates, protein, glycaemic load and index were measured using the Harvard semi-quantitative Food Frequency questionnaire at time of study entry, 28 and 36 weeks’ gestation. Fetal ultrasound measurements of biometry and adiposity were obtained at 28 and 36 weeks’ gestation. Linear regression models were used to associate between dietary factors and fetal growth and adiposity measurements. There were 721 women included in this exploratory analysis. A 10 unit increase in the log total energy was associated with a reduction in mid-thigh lean mass by 4.94 mm at 28 weeks (95% CI −9.57 mm, −0.32 mm; p = 0.036) and 7.02 mm at 36 weeks (95% CI −13.69 mm, −0.35 mm; p = 0.039). A 10 unit increase in Healthy Eating Index score was associated with a reduced mean subscapular skin fold measure at 28 weeks by 0.17 mm (95% CI −0.32 mm, −0.03 mm; p = 0.021). We did not identify consistent associations between maternal diet and measures of fetal growth and adiposity in overweight and obese women.

Conduct and reporting of acceptability, attitudes, beliefs and experiences of pregnant women in randomised trials on diet and lifestyle interventions: A systematic review

OBJECTIVE

To evaluate the conduct and reporting of views of pregnant women on the acceptability, attitudes, beliefs and their experiences in randomised trials on diet and lifestyle interventions.

STUDY DESIGN

We undertook a systematic review of literature of randomised trials identified from our previous search in major electronic databases (until February 2017) without language restrictions. We included trials on diet and lifestyle interventions that reported acceptability, attitudes, beliefs and experiences of pregnant women. The quality of papers was evaluated using the Critical Skills Appraisal Programme (CASP) framework. Data were extracted for the following domains: acceptability, intention, behaviour, attitudes and factors influencing participation. The proportion of studies that reported the various components in each domain was reported in percentages.

RESULTS

Of the 110 trials on diet and lifestyle in pregnancy, 24 reported on views of pregnant women. Acceptability of the provided information to the woman was reported in 84% (20/24), compared to 12% (3/24) on acceptability to partner or to family. Mother's intention to adhere to intervention in pregnancy was reported in 68% (17/24) of studies vs.only 16% (4/24) on family's intentions to support adherence. Changes in mother's behaviour were reported for consuming specific components of diet such as nuts (8%, 2/24), olive oil (12%, 3/24) and fruit (40%, 10/24) vs. 16% (4/24) of trials reporting changes in family's behaviour. While knowledge of food ingredients (72%, 18/24), and attitude to gestational weight gain were commonly reported (66%, 16/24) in over two-thirds of studies, only half assessed attitude to participation in research (45%, 11/24). All studies reported facilitators for uptake of intervention such as personalised support (100%, 24/24), with half (52%, 13/24) on beliefs about weight, and less than 10% (2/24) about baby's health.

CONCLUSION

The focus on studies is mainly on the mother, and less on family. Further studies are needed with a holistic approach to ensure that such interventions when implemented are accepted by women and their families.