National Institute for Health Research (NIHR) Health Technology Assessment) programme (No
12/01/50)

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Effect of diet and physical activity based interventions in pregnancy on gestational weight gain and pregnancy outcomes: meta-analysis of individual participant data from randomised trials

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.

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

Perinatal growth abnormalities program susceptibility to childhood obesity, which is further exaggerated by maternal overweight and obesity (MO) during pregnancy. Exercise is highly accessible, but reports about the benefits of maternal exercise on fetal growth and childhood obesity outcomes are inconsistent, reducing the incentives for pregnant women to participate in exercise to improve children’s perinatal growth. This systematic review and meta-analysis aims to establish evidence-based efficacy of exercise in mothers with normal weight (MNW) and MO during pregnancy in reducing the risks of perinatal growth abnormalities and childhood obesity. In addition, the impacts of exercise volume are also assessed. The PubMed, ScienceDirect, Web of Science, and Cochrane Library databases were searched from inception to February 15, 2020. We included randomized controlled trials with exercise-only intervention or exercise with other confounders in pregnant MNW (body mass index, BMI 18.5–24.9 kg/m2) and MO (BMI ≥ 25 kg/m2), which were further subgrouped in the meta-analysis. Primary outcomes included birth weight, preterm birth, small for gestational age (SGA), large for gestational age (LGA), infant and childhood weight, and childhood obesity. A linear meta-regression analysis was also used to explore the effects of exercise volume on outcomes. 99 studies were included in the meta-analysis (n = 596,876), and individual study quality ranged from fair to good according to the Newcastle–Ottawa scale assessment. Exercise only interventions in MNW reduced preterm birth by 15% (26 studies, n = 76,132; odds ratio [OR] 0.85; 95% CI 0.72, 1.01; I2 = 83.3%), SGA by 17% (33 studies, n = 92,351; OR 0.83; 95% CI 0.71, 0.98; I2 = 74.5%) and LGA by 17% (29 studies, n = 84,310; OR 0.83; 95% CI 0.74, 0.95; I2 = 60.4%). Exercise only interventions in MO reduced preterm birth by 33% (2 studies, n = 3,050; OR 0.67; 95% CI 0.70, 0.96; I2 = 0%), SGA by 27% (8 studies, n = 3,909; OR 0.73; 95% CI 0.50, 1.05; I2 = 40.4%) and LGA by 55% (9 studies, n = 81,581; OR 0.45; 95% CI 0.18, 1.11; I2 = 98.3%). Exercise only interventions in MNW reduced childhood obesity by 53% (3 studies, n = 6,920; OR 0.47; 95% CI 0.36, 0.63; I2 = 77.0%). However, no significant effect was observed in outcomes from exercise confounders in either MNW or MO. In the meta-regression, the volume of exercise-only intervention in MNW was negatively associated with birth weight, greatly driven by volumes more than 810 metabolic equivalents (MET)-min per week. Other outcomes were not associated with exercise volume. This systematic review and meta-analysis suggests that exercise during pregnancy in both MNW and MO safely and effectively reduce the risks of preterm birth, SGA, and LGA. Furthermore, MNW exercise also reduces the risk of childhood obesity. Overall, regardless of prepregnancy BMI, maternal exercise during pregnancy provides an excellent opportunity to mitigate the high prevalence of adverse birth outcomes and childhood obesity.

/pdf/effects-of-maternal-exercise-during-pregnancy-on-perinatal-3xc4kafplo.pdf

Effects of Maternal Exercise During Pregnancy on Perinatal Growth and Childhood Obesity Outcomes: A Meta-analysis and Meta-regression

......................................................................................................................................4 Executive Summary ....................................................................................................................5 Table contents .............................................................................................................................8 List of Figures ...........................................................................................................................10 List of Tables ............................................................................................................................12 List of Appendices ....................................................................................................................14 Abbreviations ............................................................................................................................16 Acknowledgements ...................................................................................................................17 Peer-reviewed publications arising from this thesis .................................................................20 Chapter

Diet and physical activity based interventions in pregnancy: Study-level and Individual Participant Data (IPD) meta-analyses

A Comparison of the Cost-Effectiveness of Lifestyle Interventions in Pregnancy

Objective
To explore the effects of walking exercise during late trimester on pregnancy outcome of low-risk primipara.


Methods
A prospective randomized controlled study was conducted for 123 cases of low-risk primipara who had regular prenatal care at Shengjing Hospital, China Medical University from July 2012 to June 2013. And informed consent was obtained. The control group included 116 cases of other low-risk primipara in the same period. Except that the experimental group had regular structured walking exercise from 34 weeks of gestational age to delivery, other consulting guidance were the same as the control group. The inter-group differences, such as delivery mode, mean body weight gain per week after 34 weeks of gestation, duration of labor, labor pain perception, neonatal weight and neonatal birth condition, were detected and analyzed.


Results
Finally there were 13 and 8 dropouts in experimental and control groups respectively. For two groups, the rate of caesarean section was 12.7% and 18.5%, the mean body weight gain per week after 34 weeks of gestational age (0.41±0.13) and (0.56±0.09) kg, the labor pain score are 6.1±1.9 and 7.6±2.3, the duration of labor (12±4) and (15±6) h, the neonatal birth weight (3.4±0.3) and (3.7±0.6) kg and the rate of macrosomia 4.5% and 7.4% respectively. The differences had statistical significance (P 0.05).


Conclusion
Simple, safe and effective, walking exercise during late trimester may improve the pregnancy outcomes of low-risk primipara.


Key words: 
Pregnancy outcome; Exercise; Delivery

Caixia Liu

Papers

[Effects of walking exercise during late trimester on pregnancy outcome of low-risk primipara].