Prevention of gestational diabetes: design of a cluster-randomized controlled trial and one-year follow-up

A socio-ecological model of factors influencing physical activity in pregnant women: a systematic review

Physical activity (PA) is safe for most pregnant women, improving both maternal fitness and birth outcomes. Despite evidence of benefits, most pregnant women eliminate or reduce PA during pregnancy. This systematic review aimed to analyze the factors affecting maternal PA during pregnancy with reference to a socio-ecological model. A systematic search of relevant published studies between 2001 and 2022 was conducted through PubMed, Scopus, Web of Science, Academic Search Ultimate, Medline, and SPORTDiscus with full text via the EBSCO platform. A total of 32 studies that met the inclusion criteria were reviewed. The findings revealed that various study designs can lead to different outcomes in terms of what is identified as a PA facilitator or barrier. The factors that positively influenced PA in pregnant women were: higher levels of education, knowledge, and skills, as well as access to mass media. Conversely, lower levels of education, lack of knowledge and skills, low income, pregnancy discomforts, limited time, safety concerns, and societal perceptions of PA in pregnancy acted as barriers. Additionally, family, colleagues/friends, and partners could either support or hinder PA. Factors affecting overall maternal PA were somewhat different from those affecting the moderate-to-vigorous intensity of PA. Pregnant women receive little organizational and policy support. There is an urgent need to provide accessible information and resource systems for pregnant women. Since most pregnant women are motivated to engage in PA and susceptible to family advice, interventions should not be limited only to pregnant women, but should involve a family member, especially partners. There is a need to take global, systemic actions to promote an active lifestyle in pregnancy. Addressing safety concerns related to PA during pregnancy should be a significant part of these promotional activities.

Methylation status of VTRNA2-1/nc886 is stable across populations, monozygotic twin pairs and in majority of tissues

Aims & methods: The aim of this study was to characterize the methylation level of a polymorphically imprinted gene, VTRNA2-1/nc886, in human populations and somatic tissues.48 datasets, consisting of more than 30 tissues and >30,000 individuals, were used. Results: nc886 methylation status is associated with twin status and ethnic background, but the variation between populations is limited. Monozygotic twin pairs present concordant methylation, whereas ∼30% of dizygotic twin pairs present discordant methylation in the nc886 locus. The methylation levels of nc886 are uniform across somatic tissues, except in cerebellum and skeletal muscle. Conclusion: The nc886 imprint may be established in the oocyte, and, after implantation, the methylation status is stable, excluding a few specific tissues.

Impact of missing outcome data in meta-analyses of lifestyle interventions during pregnancy to reduce postpartum weight retention: An overview of systematic reviews with meta-analyses and additional sensitivity analyses

High risk of bias associated with missing outcome data (MOD) in meta-analyses (MAs) of the effects of lifestyle interventions during pregnancy on postpartum weight retention (PPWR) casts doubt on whether such interventions can be relied upon as truly effective. This systematic overview of three MAs (19 RCTs), each with high MOD rates in the subset of RCTs included, examined how MOD were addressed in the estimation of summary intervention effects. All MAs reported beneficial and statistically significant intervention effects estimated based on complete case analyses, deemed valid if MOD was missing at random (MAR). Therefore, we conducted sensitivity analyses using pattern mixture models and informative missingness parameters (describing how the outcome in the missing participants may be related to the outcome in the completers), to ascertain the robustness of the estimates to reasonable deviations from the MAR assumption. In plausible scenarios where the response in intervention group participants with versus without MOD was worse (by just 0.5 kg), effect estimates were attenuated in all MAs and no longer statistically significant in two MAs. Statistical significance was retained when all 19 RCTs identified across MAs were examined together in a broader meta-analysis: -0.63 kg (95%CI -0.17, -0.08), but the clinical relevancy of effects of this magnitude remains unclear.

Effects of dietary counselling on micronutrient intakes in pregnant women in Finland

The intake of some micronutrients is still a public health challenge for pregnant women in Finland. This study examined the effects of dietary counselling on micronutrient intakes among pregnant women at increased risk of gestational diabetes mellitus in Finland. This study utilised data from was a cluster‐randomised controlled trial (n = 399), which aimed to prevent gestational diabetes. In the intervention group, the dietary counselling was carried out at four routine visits to maternity care and focused on dietary fat, fibre and saccharose intake. A validated 181‐item food frequency questionnaire was used for evaluating the participants' food consumption and nutrient intakes. The differences in changes in micronutrient intakes from baseline (pre‐pregnancy) to 36–37 weeks' gestation were compared between the intervention and the usual care groups using multilevel mixed‐effects linear regression models, adjusted for confounders. Based on the multiple‐adjusted model, the counselling increased the intake of niacin equivalent (coefficient 0.50, 95% confidence interval [CI] 0.03–0.97), vitamin D (0.24, CI 0.05–0.43), vitamin E (0.46, CI 0.26–0.66) and magnesium (5.05, CI 0.39–9.70) and maintained the intake of folate (6.50, CI 1.44–11.56), from early pregnancy to 36 to 37 weeks' gestation. Except for folate and vitamin D, the mean intake of the micronutrients from food was adequate in both groups at baseline and the follow‐up. In conclusion, the dietary counselling improved the intake of several vitamins and minerals from food during pregnancy. Supplementation on folate and vitamin D is still needed during pregnancy.

Lifestyle intervention for gestational diabetes prevention in rural woman of Shoush city

BACKGROUND

Physical activity and nutrition interventions are the most important ways to prevent gestational diabetes. The purpose of the study was to determine the effect of healthy lifestyle intervention to promote preventive behaviors of gestational diabetes in the rural woman of Shoush city.

MATERIALS AND METHODS

In an experimental study, 60 pregnant women were selected using simple random sampling and allocate into intervention group (n = 30) and nutrition program. The study was conducted from September to June 2018. The data were collected in baseline and 1 month and 3 months of follow-up phase and were analyzed using Chi-square test, repeated-measure test, and generalized linear model (GLM). The α = 0.05 was considered as significance.

RESULTS

The mean age in the intervention and control group was 25.9 ± 5.6 and 27.2 ± 5.9, respectively. The GLM test showed a significant increase in the physical activity level and the mean of nutrition behaviors within the intervention group over time (P = 0.013). Further, based on the results of repeated-measure test, the mean of weekly MET-minute was increased in the intervention group in comparison to the control group at 1 month and 3 months of follow-up (P < 0.001).

DISCUSSION AND CONCLUSION

The lifestyle interventions are appropriate programs to the reduction of the risk of development of gestational diabetes in pregnant women.

Protocol for a randomized controlled trial of pre-pregnancy lifestyle intervention to reduce recurrence of gestational diabetes: Gestational Diabetes Prevention/Prevención de la Diabetes Gestacional

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with several maternal complications in pregnancy, including preeclampsia, preterm labor, need for induction of labor, and cesarean delivery as well as increased long-term risks of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM raises the risk for complications in offspring as well, including stillbirth, macrosomia, and birth trauma, and long-term risk of metabolic disease. One of the strongest risk factors for GDM is the occurrence of GDM in a prior pregnancy. Preliminary data from epidemiologic and bariatric surgery studies suggest that reducing body weight before pregnancy can prevent the development of GDM, but no adequately powered trial has tested the effects of a maternal lifestyle intervention before pregnancy to reduce body weight and prevent GDM recurrence.

METHODS

The principal aim of the Gestational Diabetes Prevention/Prevención de la Diabetes Gestacional is to determine whether a lifestyle intervention to reduce body weight before pregnancy can reduce GDM recurrence. This two-site trial targets recruitment of 252 women with overweight and obesity who have previous histories of GDM and who plan to have another pregnancy in the next 1-3 years. Women are randomized within site to a comprehensive pre-pregnancy lifestyle intervention to promote weight loss with ongoing treatment until conception or an educational control group. Participants are assessed preconceptionally (at study entry, after 4 months, and at brief quarterly visits until conception), during pregnancy (at 26 weeks' gestation), and at 6 weeks postpartum. The primary outcome is GDM recurrence, and secondary outcomes include fasting glucose, biomarkers of cardiometabolic disease, prenatal and perinatal complications, and changes over time in weight, diet, physical activity, and psychosocial measures.

DISCUSSION

The Gestational Diabetes Prevention /Prevención de la Diabetes Gestacional is the first randomized controlled trial to evaluate the effects of a lifestyle intervention delivered before pregnancy to prevent GDM recurrence. If found effective, the proposed lifestyle intervention could lay the groundwork for shifting current treatment practices towards the interconception period and provide evidence-based preconception counseling to optimize reproductive outcomes and prevent GDM and associated health risks.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02763150 . Registered on May 5, 2016.

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.

Physical Activity and Body Composition in Children and Their Mothers According to Mother's Gestational Diabetes Risk: A Seven-Year Follow-Up Study

Background and Objectives: There is lack of knowledge on whether mothers' gestational diabetes (GDM) risk is related to their physical activity (PA) or their children's PA and body composition. We aimed to examine the difference in (1) change in self-reported PA from pre-pregnancy to seven-year follow-up and (2) accelerometer-based PA at seven years after delivery between the mothers having GDM risk (GDMRyes-mothers) and not having GDM risk (GDMRno-mothers). Furthermore, we examined the difference in children's PA and/or body composition at six years of age according to their mothers' GDM risk. Materials and Methods: The study included 199 Finnish women. GDM risk factors were screened at the beginning of pregnancy, and the women were classified as GDMRyes-mothers if they had at least one GDM risk factor (body mass index ≥25 kg/m²; age ≥40 years; family history of diabetes; GDM, signs of glucose intolerance, or newborn's macrosomia (≥4500 g) in earlier pregnancy) or as GDMRno-mothers if they had no risk factors. Mothers' PA was assessed by self-reporting at 8-12 gestational weeks concerning pre-pregnancy PA and at a follow-up seven years after the delivery. Moreover, mothers' and their children's PA was measured using a triaxial Hookie AM20-accelerometer at seven years after delivery. Children's body composition was assessed using a TANITA bioelectrical impedance device. Adjusted linear regression analyses were applied. Results: GDMRno-mothers increased their self-reported PA more than GDMRyes-mothers from pre-pregnancy to the seven-year follow-up. Concerning women's measured PA as well as children's PA and body composition at seven years after delivery, the differences were non-significant between GDMRyes-mothers and GDMRno-mothers. However, of the GDM risk factors, mothers' pre-pregnancy body mass index was positively related to unhealthier body composition in boys at six years of age. Conclusion: Health promotion should be targeted at women with GDM risk factors, in particular overweight women, in enhancing women's PA in the long term and their children's healthy body composition.

Exercise during pregnancy has a preventative effect on excessive maternal weight gain and gestational diabetes. A randomized controlled trial

BACKGROUND

Excessive gestational weight gain is associated with several adverse events and pathologies during pregnancy.

OBJECTIVE

The purpose of this study was to examine the effects of an exercise program throughout pregnancy on maternal weight gain and prevalence of gestational diabetes.

METHOD

A randomized controlled trial was designed that included an exercise intervention group (EG) and standard care control group (CG). The exercise intervention included moderate aerobic exercise performed three days per week (50-55minutes per session) for 8-10 weeks to 38-39 weeks gestation.

RESULTS

594 pregnant women were assessed for eligibility and 456 were included (EG n=234; CG n=222). The results showed a higher percentage of pregnant women gained excessive weight in the CG than in the EG (30.2% vs 20.5% respectively; odds ratio, 0.597; 95% confidence interval, 0.389-0.916; p=0.018). Similarly, the prevalence of gestational diabetes was significantly higher in the CG than the EG (6.8% vs 2.6% respectively; odds ratio, 0.363; 95% confidence interval, 0.138-0.953; p=0.033).

CONCLUSION

The results of this trial indicate that exercise throughout pregnancy can reduce the risk of excessive maternal weight gain and gestational diabetes.

Attenuating Pregnancy Weight Gain-What Works and Why: A Systematic Review and Meta-Analysis

Excessive maternal gestational weight gain (GWG) contributes to generational obesity. Our aim was to explore efficacy and intervention characteristics (trimester, duration, frequency, intensity, and delivery method) of interventions to prevent excessive GWG. CINAHL, Cochrane, EMBASE, LILACS, MEDLINE, PsycINFO, and Scopus were searched up to May 2018 (no date or language restrictions). Keywords and MeSH terms for diet, GWG, intervention, lifestyle, maternal, physical activity, and pregnancy were used to locate randomized-controlled trials (RCTs). The Cochrane Collaboration tool for assessing risk of bias was applied. Eighty-nine RCTs were included. Meta-analysis (60 trials) estimated that women in diet only (WMD: -3.27; 95% CI: -4.96, -1.58, p < 0.01), physical activity (PA) (WMD: -1.02; 95% CI: -1.56, -0.49, p < 0.01), and lifestyle interventions (combining diet and PA) (WMD: -0.84; 95% CI: -1.29, -0.39, p < 0.01) gained significantly less weight than controls. The three eHealth interventions favored neither intervention nor control (WMD: -1.06; 95% CI: -4.13, 2.00, p = 0.50). Meta-regression demonstrated no optimal duration, frequency, intensity, setting, or diet type. Traditional face to face delivery of weight management interventions during pregnancy can be successful. Delivery via eHealth has potential to extend its reach to younger women but needs further evaluation of its success.

Enablers and barriers to physical activity in overweight and obese pregnant women: an analysis informed by the theoretical domains framework and COM-B model

Background

Obesity during pregnancy is associated with increased risk of gestational diabetes mellitus (GDM) and other complications. Physical activity is a modifiable lifestyle factor that may help to prevent these complications but many women reduce their physical activity levels during pregnancy. Interventions targeting physical activity in pregnancy are on-going but few identify the underlying behaviour change mechanisms by which the intervention is expected to work. To enhance intervention effectiveness, recent tools in behavioural science such as the Theoretical Domains Framework (TDF) and COM-B model (capability, opportunity, motivation and behaviour) have been employed to understand behaviours for intervention development. Using these behaviour change methods, this study aimed to identify the enablers and barriers to physical activity in overweight and obese pregnant women.

Methods

Semi-structured interviews were conducted with a purposive sample of overweight and obese women at different stages of pregnancy attending a public antenatal clinic in a large academic maternity hospital in Cork, Ireland. Interviews were recorded and transcribed into NVivo V.10 software. Data analysis followed the framework approach, drawing on the TDF and the COM-B model.

Results

Twenty one themes were identified and these mapped directly on to the COM-B model of behaviour change and ten of the TDF domains. Having the social opportunity to engage in physical activity was identified as an enabler; pregnant women suggested being active was easier when supported by their partners. Knowledge was a commonly reported barrier with women lacking information on safe activities during pregnancy and describing the information received from their midwife as ‘limited’. Having the physical capability and physical opportunity to carry out physical activity were also identified as barriers; experiencing pain, a lack of time, having other children, and working prevented women from being active.

Conclusion

A wide range of barriers and enablers were identified which influenced women’s capability, motivation and opportunity to engage in physical activity with “knowledge” as the most commonly reported barrier. This study is a theoretical starting point in making a ‘behavioural diagnoses’ and the results will be used to inform the development of an intervention to increase physical activity levels among overweight and obese pregnant women.

Electronic supplementary material

The online version of this article (10.1186/s12884-018-1816-z) contains supplementary material, which is available to authorized users.

Combined diet and exercise interventions for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a wide range of adverse health consequences for women and their infants in the short and long term. With an increasing prevalence of GDM worldwide, there is an urgent need to assess strategies for GDM prevention, such as combined diet and exercise interventions. This is an update of a Cochrane review that was first published in 2015.

OBJECTIVES

To assess the effects of diet interventions in combination with exercise interventions for pregnant women for preventing GDM, and associated adverse health consequences for the mother and her infant/child.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (27 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and cluster-RCTs, comparing combined diet and exercise interventions with no intervention (i.e. standard care), that reported on GDM diagnosis as an outcome. Quasi-RCTs were excluded. Cross-over trials were not eligible for inclusion. We planned to include RCTs comparing two or more different diet/exercise interventions, however none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed the risk of bias of the included trials and assessed quality of evidence for selected maternal and infant/child outcomes using the GRADE approach. We checked data for accuracy.

MAIN RESULTS

In this update, we included 23 RCTs (involving 8918 women and 8709 infants) that compared combined diet and exercise interventions with no intervention (standard care). The studies varied in the diet and exercise programs evaluated and health outcomes reported. None reported receiving funding from a drug manufacturer or agency with interests in the results. Overall risk of bias was judged to be unclear due to the lack of methodological detail reported. Most studies were undertaken in high-income countries.For our primary review outcomes, there was a possible reduced risk of GDM in the diet and exercise intervention group compared with the standard care group (average risk ratio (RR) 0.85, 95% confidence interval (CI) 0.71 to 1.01; 6633 women; 19 RCTs; Tau² = 0.05; I² = 42%; P = 0.07; moderate-quality evidence). There was also a possible reduced risk of caesarean section (RR 0.95, 95% CI 0.88 to 1.02; 6089 women; 14 RCTs; moderate-quality evidence). No clear differences were seen between groups for pre-eclampsia (RR 0.98, 95% CI 0.79 to 1.22; 5366 participants; 8 RCTs; low-quality evidence), pregnancy-induced hypertension and/or hypertension (average RR 0.78, 95% CI 0.47 to 1.27; 3073 participants; 6 RCTs; Tau² = 0.19; I² = 62%; very low-quality evidence), perinatal mortality (RR 0.82, 95% CI 0.42 to 1.63; 3757 participants; 2 RCTs; low-quality evidence) or large-for-gestational age (RR 0.93, 95% CI 0.81 to 1.07; 5353 participants; 11 RCTs; low-quality evidence). No data were reported for infant mortality or morbidity composite.Subgroup analyses (based on trial design, maternal body mass index (BMI) and ethnicity) revealed no clear differential treatment effects. We were unable to assess the impact of maternal age, parity and specific features of the diet and exercise interventions. Findings from sensitivity analyses (based on RCT quality) generally supported those observed in the main analyses. We were not able to perform subgroup analyses based on maternal age, parity or nature of the exercise/dietary interventions due to the paucity of information/data on these characteristics and the inability to meaningfully group intervention characteristics.For most of the secondary review outcomes assessed using GRADE, there were no clear differences between groups, including for perineal trauma (RR 1.27, 95% CI 0.78 to 2.05; 2733 participants; 2 RCTs; moderate-quality evidence), neonatal hypoglycaemia (average RR 1.42, 95% CI 0.67 to 2.98; 3653 participants; 2 RCTs; Tau² = 0.23; I² = 77%; low quality evidence); and childhood adiposity (BMI z score) (MD 0.05, 95% CI -0.29 to 0.40; 794 participants; 2 RCTs; Tau² = 0.04; I² = 59%; low-quality evidence). However, there was evidence of less gestational weight gain in the diet and exercise intervention group compared with the control group (mean difference (MD) -0.89 kg, 95% CI -1.39 to -0.40; 5052 women; 16 RCTs; Tau² = 0.37; I² = 43%;moderate-quality evidence). No data were reported for maternal postnatal depression or type 2 diabetes; childhood/adulthood type 2 diabetes, or neurosensory disability.

AUTHORS' CONCLUSIONS

Moderate-quality evidence suggests reduced risks of GDM and caesarean section with combined diet and exercise interventions during pregnancy as well as reductions in gestational weight gain, compared with standard care. There were no clear differences in hypertensive disorders of pregnancy, perinatal mortality, large-for-gestational age, perineal trauma, neonatal hypoglycaemia, and childhood adiposity (moderate- tovery low-quality evidence).Using GRADE methodology, the evidence was assessed as moderate to very low quality. Downgrading decisions were predominantly due to design limitations (risk of bias), and imprecision (uncertain effect estimates, and at times, small sample sizes and low event rates), however two outcomes (pregnancy-induced hypertension/hypertension and neonatal hypoglycaemia), were also downgraded for unexplained inconsistency (statistical heterogeneity).Due to the variability of the diet and exercise components tested in the included studies, the evidence in this review has limited ability to inform practice. Future studies could describe the interventions used in more detail, if and how these influenced behaviour change and ideally be standardised between studies. Studies could also consider using existing core outcome sets to facilitate more standardised reporting.

Can exercise or physical activity help improve postnatal depression and weight loss? A systematic review

Despite exercise or physical activity (PA) being effective on depression and weight management generally, its effectiveness remains uncertain during postpartum. This systematic review aimed to determine the efficacy of exercise or PA interventions on postnatal depression (PND) and weight loss, with a subsequent aim to identify more effective intervention approaches. Using PRISMA guidelines, data searches conducted across six databases. Nine studies fulfilled our inclusion criteria. Based on identified studies (some with high-quality RCT designs), there was inconsistency as to whether exercise or PA simultaneously reduced PND symptoms and assisted weight loss (or related body composition indices). Two (22.2%) identified changes in both outcomes with small effect sizes. Four studies (44.4%) reported changes in one outcome, typically PND with variable effect sizes, while three studies (33.3%) reported no effect. Studies implemented different exercise/PA modalities (commonly walking) and incorporated various support strategies to assist intervention participation and adherence. Studies identified as most likely to associate with PND and/or weight loss changes were those with supervision (1-1, group), structure (weekly frequency, scheduled durations and moderate intensity), which adhered to specific exercise/PA guidelines over an extended postpartum period (e.g. 12 weeks +) and were supplemented by several psycho-social support strategies (e.g. educational information, exercise/PA advice, and counselling). Future studies need to carefully address prior study methodological weaknesses (e.g. study design, inclusion criteria, measurement, reporting, assessing confounding factors), further examine proposed more beneficial exercise/PA intervention approaches, and consider how exercise/PA could be best delivered in practice to benefit women's postpartum health.

Pregnancy to postpartum transition of serum metabolites in women with gestational diabetes

CONTEXT

Gestational diabetes is commonly linked to development of type 2 diabetes mellitus (T2DM). There is a need to characterize metabolic changes associated with gestational diabetes in order to find novel biomarkers for T2DM.

OBJECTIVE

To find potential pathophysiological mechanisms and markers for progression from gestational diabetes mellitus to T2DM by studying the metabolic transition from pregnancy to postpartum.

DESIGN

The metabolic transition profile from pregnancy to postpartum was characterized in 56 women by mass spectrometry-based metabolomics; 11 women had gestational diabetes mellitus, 24 had normal glucose tolerance, and 21 were normoglycaemic but at increased risk for gestational diabetes mellitus. Fasting serum samples collected during trimester 3 (gestational week 32±0.6) and postpartum (10.5±0.4months) were compared in diagnosis-specific multivariate models (orthogonal partial least squares analysis). Clinical measurements (e.g., insulin, glucose, lipid levels) were compared and models of insulin sensitivity and resistance were calculated for the same time period.

RESULTS

Women with gestational diabetes had significantly increased postpartum levels of the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine, and their circulating lipids did not return to normal levels after pregnancy. The increase in BCAAs occurred postpartum since the BCAAs did not differ during pregnancy, as compared to normoglycemic women.

CONCLUSIONS

Postpartum levels of specific BCAAs, notably valine, are related to gestational diabetes during pregnancy.

Metabolic syndrome in Finnish women 7 years after a gestational diabetes prevention trial

BACKGROUND

Risk for developing metabolic syndrome (MeS) after delivery is high among women with gestational diabetes mellitus (GDM), but little is known about development of MeS among women with risk factors for GDM during pregnancy. In the present study, we studied the prevalence of MeS 7 years postpartum among women with GDM risk factors during pregnancy, women with early GDM diagnosis and women without GDM risk factors. We also analysed the early pregnancy risk factors associated with MeS.

METHODS

A Finnish cluster randomised controlled GDM prevention trial was conducted in 2007-2009. The prevalence of MeS according to International Diabetes Federation criteria was determined in the follow-up study 7 years after original trial. Eligible participants (n=289) in 4 study groups (intervention (n=83) and usual care (n=87) with GDM risk factors; early GDM (n=51), and healthy control without GDM risk factors (n=68)) were evaluated for MeS. Binary logistic regression models were used to analyse risk factors associated with MeS.

RESULTS

7 years postpartum, the MeS prevalence was 14% (95% CI 8% to 25%) in the intervention group; 15% (CI 8% to 25%) in the usual care group; 50% (CI 35% to 65%) in the early GDM group and 7% (CI 2% to 18%) in the healthy control group. OR for MeS in women with GDM risk factors did not differ from the healthy control group. Body mass index (BMI)-adjusted OR for MeS was 9.18 (CI 1.82 to 46.20) in the early GDM group compared with the healthy control group. Increased prepregnancy BMI was associated with MeS (OR, 1.17, CI 1.08 to 1.28, adjusted for group).

CONCLUSIONS

Increased prepregnancy BMI and early GDM diagnosis were the strongest risk factors for developing MeS 7 years postpartum. Overweight and obese women and especially those with early GDM should be monitored and counselled for cardiometabolic risk factors after delivery.

Dietary advice interventions in pregnancy for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a form of diabetes occurring during pregnancy which can result in short- and long-term adverse outcomes for women and babies. With an increasing prevalence worldwide, there is a need to assess strategies, including dietary advice interventions, that might prevent GDM.

OBJECTIVES

To assess the effects of dietary advice interventions for preventing GDM and associated adverse health outcomes for women and their babies.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (3 January 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs assessing the effects of dietary advice interventions compared with no intervention (standard care), or to different dietary advice interventions. Cluster-RCTs were eligible for inclusion but none were identified.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included studies. Data were checked for accuracy. The quality of the evidence was assessed using the GRADE approach.

MAIN RESULTS

We included 11 trials involving 2786 women and their babies, with an overall unclear to moderate risk of bias. Six trials compared dietary advice interventions with standard care; four compared low glycaemic index (GI) with moderate- to high-GI dietary advice; one compared specific (high-fibre focused) with standard dietary advice. Dietary advice interventions versus standard care (six trials) Considering primary outcomes, a trend towards a reduction in GDM was observed for women receiving dietary advice compared with standard care (average risk ratio (RR) 0.60, 95% confidence interval (CI) 0.35 to 1.04; five trials, 1279 women; Tau² = 0.20; I² = 56%; P = 0.07; GRADE: very low-quality evidence); subgroup analysis suggested a greater treatment effect for overweight and obese women receiving dietary advice. While no clear difference was observed for pre-eclampsia (RR 0.61, 95% CI 0.25 to 1.46; two trials, 282 women; GRADE: low-quality evidence) a reduction in pregnancy-induced hypertension was observed for women receiving dietary advice (RR 0.30, 95% CI 0.10 to 0.88; two trials, 282 women; GRADE: low-quality evidence). One trial reported on perinatal mortality, and no deaths were observed (GRADE: very low-quality evidence). None of the trials reported on large-for-gestational age or neonatal mortality and morbidity.For secondary outcomes, no clear differences were seen for caesarean section (average RR 0.98, 95% CI 0.78 to 1.24; four trials, 1194 women; Tau² = 0.02; I² = 36%; GRADE: low-quality evidence) or perineal trauma (RR 0.83, 95% CI 0.23 to 3.08; one trial, 759 women; GRADE: very low-quality evidence). Women who received dietary advice gained less weight during pregnancy (mean difference (MD) -4.70 kg, 95% CI -8.07 to -1.34; five trials, 1336 women; Tau² = 13.64; I² = 96%; GRADE: low-quality evidence); the result should be interpreted with some caution due to considerable heterogeneity. No clear differences were seen for the majority of secondary outcomes reported, including childhood/adulthood adiposity (skin-fold thickness at six months) (MD -0.10 mm, 95% CI -0.71 to 0.51; one trial, 132 children; GRADE: low-quality evidence). Women receiving dietary advice had a lower well-being score between 14 and 28 weeks, more weight loss at three months, and were less likely to have glucose intolerance (one trial).The trials did not report on other secondary outcomes, particularly those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood type 2 diabetes; and neurosensory disability. Low-GI dietary advice versus moderate- to high-GI dietary advice (four trials) Considering primary outcomes, no clear differences were shown in the risks of GDM (RR 0.91, 95% CI 0.63 to 1.31; four trials, 912 women; GRADE: low-quality evidence) or large-for-gestational age (average RR 0.60, 95% CI 0.19 to 1.86; three trials, 777 babies; Tau² = 0.61; P = 0.07; I² = 62%; GRADE: very low-quality evidence) between the low-GI and moderate- to high-GI dietary advice groups. The trials did not report on: hypertensive disorders of pregnancy; perinatal mortality; neonatal mortality and morbidity.No clear differences were shown for caesarean birth (RR 1.27, 95% CI 0.79 to 2.04; two trials, 201 women; GRADE: very low-quality evidence) and gestational weight gain (MD -1.23 kg, 95% CI -4.08 to 1.61; four trials, 787 women; Tau² = 7.31; I² = 90%; GRADE: very low-quality evidence), or for other reported secondary outcomes.The trials did not report the majority of secondary outcomes including those related to long-term health and health service use and costs. We were not able to assess the following outcomes using GRADE: perineal trauma; postnatal depression; maternal type 2 diabetes; neonatal hypoglycaemia; childhood/adulthood adiposity; type 2 diabetes; and neurosensory disability. High-fibre dietary advice versus standard dietary advice (one trial) The one trial in this comparison reported on two secondary outcomes. No clear difference between the high-fibre and standard dietary advice groups observed for mean blood glucose (following an oral glucose tolerance test at 35 weeks), and birthweight.

AUTHORS' CONCLUSIONS

Very low-quality evidence from five trials suggests a possible reduction in GDM risk for women receiving dietary advice versus standard care, and low-quality evidence from four trials suggests no clear difference for women receiving low- versus moderate- to high-GI dietary advice. A possible reduction in pregnancy-induced hypertension for women receiving dietary advice was observed and no clear differences were seen for other reported primary outcomes. There were few outcome data for secondary outcomes.For outcomes assessed using GRADE, evidence was considered to be low to very low quality, with downgrading based on study limitations (risk of bias), imprecision, and inconsistency.More high-quality evidence is needed to determine the effects of dietary advice interventions in pregnancy. Future trials should be designed to monitor adherence, women's views and preferences, and powered to evaluate effects on short- and long-term outcomes; there is a need for such trials to collect and report on core outcomes for GDM research. We have identified five ongoing studies and four are awaiting classification. We will consider these in the next review update.

Effectiveness and Cost-Effectiveness of a Cluster-Randomized Prenatal Lifestyle Counseling Trial: A Seven-Year Follow-Up

There is a link between the pregnancy and its long-term influence on health and susceptibility to future chronic disease both in mother and offspring. The objective was to determine whether individual counseling on physical activity and diet and weight gain at five antenatal visits can prevent type 2 diabetes mellitus (T2DM) and overweight or improve glycemic parameters, among all at-risk-mothers and their children. Another objective was to evaluate whether gestational lifestyle intervention was cost-effective as measured with mother's sickness absence and quality-adjusted life years (QALY). This study was a seven-year follow-up study for women, who were enrolled to the antenatal cluster-randomized controlled trial (RCT). Analysis of the outcome included all women whose outcome was available, in addition with subgroup analysis including women adherent to all lifestyle aims. A total of 173 women with their children participated to the study, representing 43% (173/399) of the women who finished the original RCT. Main outcome measures were: T2DM based on medication use or fasting blood glucose or oral glucose tolerance test (OGTT), body mass index (BMI), glycosylated hemoglobin (HbA1c). None of the women were diagnosed to have T2DM. HbA1c or fasting blood glucose differences were not found among mothers or children. Differences in BMI were non-significant among mothers (Intervention 27.3, Usual care 28.1 kg/m2, p = 0.33) and children (I 21.3 vs U 22.5 kg/m2, p = 0.07). Children's BMI was significantly lower among adherent group (I 20.5 vs U 22.5, p = 0.04). The mean total cost per person was 30.6% lower in the intervention group than in the usual care group (I €2,944 vs. U €4,243; p = 0.74). Intervention was cost-effective in terms of sickness absence but not in QALY gained i.e. if society is willing to pay additional €100 per one avoided sickness absence day; there is a 90% probability of the intervention arm to be cost-effective. Long-term effectiveness of antenatal lifestyle counseling was not shown, in spite of possible effect on children's BMI. Cost-effectiveness of the intervention in terms of sickness absence may have larger societal impact.

Windows of Opportunity for Lifestyle Interventions to Prevent Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is linked with several acute maternal health risks and long-term development of type 2 diabetes, metabolic syndrome, and cardiovascular disease. Intrauterine exposure to GDM similarly increases offspring risk of early-life health complications and later disease. GDM recurrence is common, affecting 40 to 73% of women, and augments associated maternal/fetal/child health risks. Modifiable and independent risk factors for GDM include maternal excessive gestational weight gain and prepregnancy overweight and obesity. Lifestyle interventions that target diet, activity, and behavioral strategies can effectively modify body weight. Randomized clinical trials testing the effects of lifestyle interventions during pregnancy to reduce excessive gestational weight gain have generally shown mixed effects on reducing GDM incidence. Trials testing the effects of postpartum lifestyle interventions among women with a history of GDM have shown reduced incidence of diabetes and improved cardiovascular disease risk factors. However, the long-term effects of interpregnancy or prepregnancy lifestyle interventions on subsequent GDM remain unknown. Future adequately powered and well-controlled clinical trials are needed to determine the effects of lifestyle interventions to prevent GDM and identify pathways to effectively reach reproductive-aged women across all levels of society, before, during, and after pregnancy.

The HAPPY (Healthy and Active Parenting Programmme for early Years) feasibility randomised control trial: acceptability and feasibility of an intervention to reduce infant obesity

BACKGROUND

The prevalence of infant obesity is increasing, but there is a lack of evidence-based approaches to prevent obesity at this age. This study tested the acceptability and feasibility of evaluating a theory-based intervention aimed at reducing risk of obesity in infants of overweight/obese women during and after pregnancy: the Healthy and Active Parenting Programme for Early Years (HAPPY).

METHODS

A feasibility randomised controlled trial was conducted in Bradford, England. One hundred twenty overweight/obese pregnant women (Body Mass Index [BMI] ≥25 kg/m(2)) were recruited between 10-26 weeks gestation. Consenting women were randomly allocated to HAPPY (6 antenatal, 6 postnatal sessions: N = 59) or usual care (N = 61). Appropriate outcome measures for a full trial were explored, including: infant's length and weight, woman's BMI, physical activity and dietary intake of the women and infants. Health economic data were collected. Measurement occurred before randomisation and when the infant was aged 6 months and 12 months. Feasibility outcomes were: recruitment/attrition rates, and acceptability of: randomisation, measurement, and intervention. Intra-class correlations for infant weight were calculated. Fidelity was assessed through observations and facilitator feedback. Focus groups and semi-structured interviews explored acceptability of methods, implementation, and intervention content.

RESULTS

Recruitment targets were met (~20 women/month) with a recruitment rate of 30 % of eligible women (120/396). There was 30 % attrition at 12 months; 66 % of recruited women failed to attend intervention sessions, but those who attended the first session were likely to continue to attend (mean 9.4/12 sessions, range 1-12). Reaction to intervention content was positive, and fidelity was high. Group clustering was minimal; an adjusted effect size of -0.25 standard deviation scores for infant weight at 12 months (95 % CI: -0.16-0.65) favouring the intervention was observed using intention to treat analyses. No adverse events were reported.

CONCLUSIONS

The HAPPY intervention appeared feasible and acceptable to participants who attended and those delivering it, however attendance was low; adaptations to increase initial attendance are recommended. Whilst the study was not powered to detect a definitive effect, our results suggest a potential to reduce risk of infant obesity. The evidence reported provides valuable lessons to inform progression to a definitive trial.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN56735429.

Differences in sedentary time and physical activity among mothers and children using a movement-to-music video program in the home environment: a pilot study

Measured objectively, less than a quarter of adults and under half of preschool children in Finland meet the physical activity recommendations. Moreover, higher sedentary time among parents (such as watching television) is associated with higher sedentary time of their children. The study introduces an intervention based on reducing sedentary behavior among mothers and their children. It utilizes a combination of music and exercise via a motivation-targeting movement-to-music video program in the home environment. Data were collected in summer 2014 from Finland’s Pirkanmaa region. Each mother–child pair (n = 24, child age: 4–7 years) was assigned to the intervention and control group. Both groups used an accelerometer and completed physical activity diaries for two consecutive weeks (14 days) during waking hours. In addition, the intervention group was instructed to use the movement-to-music video program during the second week. Differences between groups were expected in analysis of sedentary time and physical activity between weeks 1 and 2. The parameters assessed were sedentary time (i.e., lying down or sitting), standing still, and time spent in physical activity. Less sedentary time was revealed in week 2 than in week 1 among both intervention group mothers (56.6 vs. 53.3 %) and for intervention group children (49.5 vs. 46.0 %). The opposite was true of control group mothers (52.1 vs. 52.4 %) and children (46.7 vs. 49.8 %). Within-group differences in mothers’ sedentary time correlated moderately with the children’s sedentary time (Spearman’s r = 0.56). All groups exhibited slightly more standing in the second week than in week 1. Both sets of intervention participants also engaged in more light physical activity in week 2, with the opposite evident for the two control sets. In all groups, except the control children, the proportion of moderate to vigorous physical activity was higher in the second week than the first. The use of music and video content together may yield added benefits in efforts to reduce sedentary behavior and increase physical activity among mothers and their children in the home environment.

Physical activity and health-related quality of life during pregnancy: a secondary analysis of a cluster-randomised trial

The aim of the study was to evaluate the role of physical activity before and during pregnancy on health-related quality of life (HRQoL). Data from the cluster-randomised gestational diabetes mellitus primary prevention trial conducted in maternity clinics were utilised in a secondary analysis. The cases considered were pregnant women who reported engaging in at least 150 min of moderate-intensity leisure-time physical activity per week (active women) (N = 80), and the controls were women below these recommendations (less active) (N = 258). All participants had at least one risk factor for gestational diabetes mellitus. Their HRQoL was evaluated via the validated generic instrument 15D, with HRQoL at the end of pregnancy examined in relation to changes in physical activity during pregnancy. Logistic regression models addressed age, parity, education, and pre-pregnancy body mass index. At the end of pregnancy, the expected HRQoL was higher (tobit regression coefficient 0.022, 95 % CI 0.003-0.042) among active women than less active women. Active women also had greater mobility (OR 1.98, 95 % CI 1.04-3.78), ability to handle their usual activities (OR 2.22, 95 % CI 1.29-3.81), and vitality (OR 2.08, 95 % CI 1.22-3.54) than did less active women. Active women reported higher-quality sleep (OR 2.11, 95 % CI 1.03-4.30) throughout pregnancy as compared to less active women. Meeting of the physical activity guidelines before pregnancy was associated with better overall HRQoL and components thereof related to physical activity.

Physical activity during pregnancy: predictors of change, perceived support and barriers among women at increased risk of gestational diabetes

The aim of this study was to examine the predictors of change in intensity-specific leisure-time physical activity (LTPA) during pregnancy, and the perceived support and barriers of LTPA in Finnish pregnant women at increased risk of gestational diabetes. The study population consisted of 399 pregnant women who participated in a randomized controlled trial aiming to prevent gestational diabetes. Evaluation of LTPA was based on a self-report at baseline, 26-28, and 36-37 weeks' gestation. Data on predictors of change, perceived support and barriers were collected with questionnaires and from the maternity cards. Multinomial logistic regression was used to assess associations between the variables. The average weekly minutes of light-intensity LTPA were 179 at baseline, 161 at 26-28 weeks' gestation, and 179 at 36-37 weeks' gestation. The corresponding minutes of moderate-to-vigorous-intensity LTPA were 187, 133 and 99. At 26-28 weeks' gestation, the strongest predictors for light-intensity LTPA were meeting the PA recommendations prior to pregnancy, having polytechnic education and working part-time, while having a physically active spouse prior to pregnancy was the strongest predictor for moderate-to-vigorous-intensity LTPA. The people and/or factors that encouraged women to LTPA the most were the spouse, a child, other family members and weather, whereas tiredness, nausea, perceived health, work and lack of time restricted their LTPA the most. The strongest predictors for maintaining LTPA during pregnancy were pre-pregnancy LTPA, education, working part-time and a spouse's LTPA. Most common barriers were perceived health, work and lack of time.

Rationale and methods for a randomized controlled trial of a movement-to-music video program for decreasing sedentary time among mother-child pairs

Background

Measured objectively, under a quarter of adults and fewer than half of preschool children meet the criteria set in the aerobic physical activity recommendations of the Centers for Disease Control and Prevention. Moreover, adults reportedly are sedentary (seated or lying down) for most of their waking hours. Importantly, greater amounts of sedentary time on parents’ part are associated with an increased risk of more sedentary time among their children. A randomized controlled trial targeting mother-child pairs has been designed, to examine whether a movement-to-music video program may be effective in reducing sedentary time and increasing physical activity in the home environment.

Methods

Mother-child pairs (child age of 4–7 years) will be recruited from among NELLI lifestyle-modification study five-year follow-up cohort participants, encompassing 14 municipalities in Pirkanmaa region, Finland.

Accelerometer and exercise diary data are to be collected for intervention and control groups at the first, second and eighth week after the baseline measurements. Background factors, physical activity, screen time, motivation to exercise, and self-reported height and weight, along with quality of life, will be assessed via questionnaires. After the baseline and first week measurements, the participants of the intervention group will receive a movement-to-music video program designed to reduce sedentary time and increase physical activity. Intervention group mother-child pairs will be instructed to exercise every other day while watching the video program over the next seven weeks. Information on experiences of the use of the movement-to-music video program will be collected 8 weeks after baseline. Effects of the intervention will be analyzed in line with the intention-to-treat principle through comparison of the changes in the main outcomes between intervention and control group participants. The study has received ethics approval from the Pirkanmaa Ethics Committee in Human Sciences.

Discussion

The study will yield information on the effectiveness of movement-to-music video exercise in reducing sedentary behavior. Intervention-based methods have proven effective in increasing physical activity in home environments. Music may improve exercise adherence, which creates a possibility of achieving long-term health benefits.

Trial registration

The study is registered at ClinicalTrials.gov, as NCT02270138. It was registered on October 2, 2014.

Diet or exercise, or both, for preventing excessive weight gain in pregnancy

BACKGROUND

This is an update of a Cochrane review first published in 2012, Issue 4. Excessive weight gain during pregnancy is associated with poor maternal and neonatal outcomes including gestational diabetes, hypertension, caesarean section, macrosomia, and stillbirth. Diet or exercise interventions, or both, may reduce excessive gestational weight gain (GWG) and associated poor outcomes; however, evidence from the original review was inconclusive.

OBJECTIVES

To evaluate the effectiveness of diet or exercise, or both, interventions for preventing excessive weight gain during pregnancy and associated pregnancy complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (5 November 2014), contacted investigators of the previously identified ongoing studies and scanned reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of diet or exercise, or both, interventions for preventing excessive weight gain in pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We organised RCTs according to the type of interventions and pooled data using the random-effects model in the Review Manager software. We also performed subgroup analyses according to the initial risk of adverse effects related to poor weight control. We performed sensitivity analysis to assess the robustness of the findings.

MAIN RESULTS

We included 65 RCTs, out of which 49 RCTs involving 11,444 women contributed data to quantitative meta-analysis. Twenty studies were at moderate-to-high risk of bias. Study interventions involved mainly diet only, exercise only, and combined diet and exercise interventions, usually compared with standard care. Study methods varied widely; therefore, we estimated the average effect across studies and performed sensitivity analysis, where appropriate, by excluding outliers and studies at high risk of bias.Diet or exercise, or both, interventions reduced the risk of excessive GWG on average by 20% overall (average risk ratio (RR) 0.80, 95% confidence interval (CI) 0.73 to 0.87; participants = 7096; studies = 24; I² = 52%). This estimate was robust to sensitivity analysis, which reduced heterogeneity, therefore we graded this evidence as high-quality. Interventions involving low glycaemic load diets, supervised or unsupervised exercise only, or diet and exercise combined all led to similar reductions in the number of women gaining excessive weight in pregnancy.Women receiving diet or exercise, or both interventions were more likely to experience low GWG than those in control groups (average RR 1.14, 95% CI 1.02 to 1.27; participants = 4422; studies = 11; I² = 3%; moderate-quality evidence). We found no difference between intervention and control groups with regard to pre-eclampsia (RR 0.95, 95% CI 0.77 to 1.16; participants = 5330; studies = 15; I² = 0%; high-quality evidence); however, maternal hypertension (not a pre-specified outcome) was reduced in the intervention group compared with the control group overall (average RR 0.70, 95% CI 0.51 to 0.96; participants = 5162; studies = 11; I² = 43%; low-quality evidence).There was no clear difference between groups with regard to caesarean delivery overall (RR 0.95, 95% CI 0.88 to 1.03; participants = 7534; studies = 28; I² = 9%; high-quality evidence); although the effect estimate suggested a small difference (5%) in favour of the interventions. In addition, for combined diet and exercise counselling interventions there was a 13% (-1% to 25%) reduction in this outcome (borderline statistical significance).We found no difference between groups with regard to preterm birth overall (average RR 0.91, 95% CI 0.68 to 1.22; participants = 5923; studies = 16; I² = 16%; moderate-quality evidence); however limited evidence suggested that these effect estimates may differ according to the types of interventions, with a trend towards an increased risk for exercise-only interventions.We found no clear difference between intervention and control groups with regard to infant macrosomia (average RR 0.93, 95% CI 0.86 to 1.02; participants = 8598; studies = 27; I² = 0%; high-quality evidence), although the effect estimate suggested a small difference (7% reduction) in favour of the intervention group. The largest effect size occurred in the supervised exercise-only intervention group (RR 0.81, 95% CI 0.64 to 1.02; participants = 2445; studies = 7; I² = 0%), which approached statistical significance (P = 0.07). Furthermore, in subgroup analysis by risk, high-risk women (overweight or obese women, or women with or at risk of gestational diabetes) receiving combined diet and exercise counselling interventions experienced a 15% reduced risk of infant macrosomia (average RR 0.85, 95% CI 0.73 to 1.00; participants = 3252; studies = nine; I² = 0; P = 0.05; moderate-quality evidence)There were no differences in the risk of poor neonatal outcomes including shoulder dystocia, neonatal hypoglycaemia, hyperbilirubinaemia, or birth trauma (all moderate-quality evidence) between intervention and control groups; however, infants of high-risk women had a reduced risk of respiratory distress syndrome if their mothers were in the intervention group (RR 0.47, 95% CI 0.26 to 0.85; participants = 2256; studies = two; I² = 0%; moderate-quality evidence).

AUTHORS' CONCLUSIONS

High-quality evidence indicates that diet or exercise, or both, during pregnancy can reduce the risk of excessive GWG. Other benefits may include a lower risk of caesarean delivery, macrosomia, and neonatal respiratory morbidity, particularly for high-risk women receiving combined diet and exercise interventions. Maternal hypertension may also be reduced. Exercise appears to be an important part of controlling weight gain in pregnancy and more research is needed to establish safe guidelines. Most included studies were carried out in developed countries and it is not clear whether these results are widely applicable to lower income settings.

Diet and exercise interventions for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with a wide range of adverse health consequences for women and their babies in the short and long term. With an increasing prevalence of GDM worldwide, there is an urgent need to assess strategies for GDM prevention, such as combined diet and exercise interventions.

OBJECTIVES

To assess the effects of combined diet and exercise interventions for preventing GDM and associated adverse health consequences for women and their babies.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 February 2014) and reference lists of retrieved studies. We updated the search in February 2015 but these results have not yet been incorporated and are awaiting classification.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs assessing the effects of interventions that included diet and exercise components. We included studies where combined diet and exercise interventions were compared with no intervention (i.e. standard care).We planned to also compare diet and exercise interventions with alternative diet and/or exercise interventions but no trials were identified for this comparison.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of the included studies. Data were checked for accuracy.

MAIN RESULTS

We included 13 randomised controlled trials (involving 4983 women and their babies). We assessed the included trials as being of moderate risk of bias overall.When comparing women receiving a diet and exercise intervention with those receiving no intervention, there was no clear difference in the risk of developing GDM (average risk ratio (RR) 0.92, 95% confidence interval (CI) 0.68 to 1.23; 11 trials, 3744 women), caesarean section (RR 0.92, 95% CI 0.83 to 1.01; seven trials, 3246 women), or large-for-gestational age (RR 0.90, 95% CI 0.77 to 1.05; 2950 infants). Only one trial reported on perinatal mortality, and found no clear difference in the risk of stillbirth (RR 0.99, 95% CI 0.29 to 3.42; 2202 fetuses) or neonatal death (RR 0.99, 95% CI 0.06 to 15.85; 2202 neonates).Very few differences were shown between groups for the review's secondary outcomes, including for induction of labour, perineal trauma, pre-eclampsia, postpartum haemorrhage and infection, macrosomia, birthweight, small-for-gestational age, ponderal index, neonatal hypoglycaemia requiring treatment, hyperbilirubinaemia requiring treatment, shoulder dystocia, bone fracture or nerve palsy. Women receiving a combined diet and exercise intervention were, however, found to have a reduced risk of preterm birth compared with women receiving no intervention (RR 0.71, 95% CI 0.55 to 0.93; five trials, 2713 women).A trend towards reduced weight gain during pregnancy was shown for women receiving the combined diet and exercise intervention (mean difference (MD) -0.76 kg, 95% CI -1.55 to 0.03; eight trials, 2707 women; P = 0.06, random-effects); but no clear difference in postnatal weight retention was observed overall.In relation to adherence to the interventions, a number of trials that reported on behaviour modifications showed benefits in diet- (5/8 trials) and physical activity- (4/8 trials) related behaviours for women receiving the combined diet and exercise intervention, compared with women receiving no intervention; however there was notable variation across trials in outcomes measured and results observed. Only two trials reported on well-being and quality of life of women, and did not observe differences between groups for these outcomes.Very few trials reported on outcomes relating to the use of health services, although one trial suggested a reduced length of antenatal hospital stay for women receiving a combined diet and exercise intervention (MD -0.27 days, 95% CI -0.49 to -0.05; 2153 women).No information was available on outcomes for the infant as a child or adult, or for most longer-term outcomes for the mother.

AUTHORS' CONCLUSIONS

There are limitations associated with the available RCT evidence on the effects of combined diet and exercise interventions during pregnancy for preventing GDM. Results from 13 RCTs (of moderate quality) suggest no clear difference in the risk of developing GDM for women receiving a combined diet and exercise intervention compared with women receiving no intervention. However, the ability to draw firm conclusions was limited by variations in the quality of trials, characteristics of the interventions and populations assessed, and outcome definitions between trials.Based on the data currently available, conclusive evidence is not available to guide practice. Further large, well-designed RCTs, addressing the limitations of previous studies, are needed to assess the effects of combined interventions on preventing GDM and other relevant pregnancy outcomes including caesarean birth, large-for-gestational age and perinatal mortality. Health service utilisation and costs, and longer-term outcomes for mothers and their babies should be included. We identified another 16 trials which are ongoing and we will consider these for inclusion in the next update of this review.

A comparison of a social support physical activity intervention in weight management among post-partum Latinas

BACKGROUND

Weight gain during the childbearing years and failure to lose pregnancy weight after birth contribute to the development of obesity in postpartum Latinas.

METHODS

Madres para la Salud [Mothers for Health] was a 12-month, randomized controlled trial exploring a social support intervention with moderate-intensity physical activity (PA) seeking to effect changes in body fat, fat tissue inflammation, and depression symptoms in sedentary postpartum Latinas. This report describes the efficacy of the Madres intervention.

RESULTS

The results show that while social support increased during the active intervention delivery, it declined to pre-intervention levels by the end of the intervention. There were significant achievements in aerobic and total steps across the 12 months of the intervention, and declines in body adiposity assessed with bioelectric impedance.

CONCLUSIONS

Social support from family and friends mediated increases in aerobic PA resulting in decrease in percent body fat.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01908959.

Postpartum weight retention is associated with elevated ratio of oxidized LDL lipids to HDL-cholesterol

Oxidized LDL lipids (ox-LDL) are associated with lifestyle diseases such as cardiovascular diseases, metabolic syndrome and type 2 diabetes. The present study investigated how postpartum weight retention effects on ox-LDL and serum lipids. The study is a nested comparative research of a cluster-randomized controlled trial, NELLI (lifestyle and counselling during pregnancy). During early pregnancy (8-12 weeks) and 1 year postpartum, 141 women participated in measurements for determining of plasma lipids: total cholesterol (T-C), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), triacylglycerols (TAG) and ox-LDL. Subjects were stratified into tertiles (weight loss, unaltered weight and weight gain groups) based on their weight change from baseline to follow-up. Ox-LDL was determined by baseline level of conjugated dienes in LDL lipids. Among the group of weight gainers, concentration of TAG reduced less (-0.14 vs. -0.33, p = 0.002), HDL-C reduced more (-0.31 vs. -0.16, p = 0.003) and ox-LDL/HDL-C ratio increased (3.0 vs. -0.2, p = 0.003) when compared to group of weight loss. Both T-C and LDL-C elevated more (0.14 vs. -0.21, p = 0.008; 0.31 vs. 0.07, p = 0.015) and TAG and ox-LDL reduced less (-0.33 vs. 0.20, p = 0.033; -3.33 vs. -0.68, p = 0.026) in unaltered weight group compared to weight loss group. The women who gained weight developed higher TAG and ox-LDL/HDL-C ratio as compared to those who lost weight. Postpartum weight retention of 3.4 kg or more is associated with atherogenic lipid profile.

Precocious markers of cardiovascular risk and vascular damage in apparently healthy women with previous gestational diabetes

Previous gestational diabetes mellitus (pGDM) indicates future risk for type 2 diabetes (T2DM). Insulin resistance (IR) may precede T2DM in many years and is associated with an increased risk for cardiovascular diseases.

AIM

This study aims to identify endothelial dysfunction and cardiovascular risk factors in women with pGDM.

METHODS

This cross-sectional analysis included 45 non diabetic women, 20 pGDM and 25 controls, at least one year after delivery. Body mass index (BMI), abdominal circumference (AC), blood pressure, serum lipids, liver enzymes, uric acid, nonesterified fatty acids, C-reactive protein and plasma glucose, insulin, fibrinogen and plasminogen activator inhibitor 1 were measured. HOMA IR and β were calculated. Pre and post induced ischemia videocapillaroscopy was performed in hand nailfold to evaluate microvascular morphologic aspect and functional response.

RESULTS

AC and fasting glucose were significantly higher in pGDM (p = 0.01 and p = 0.002 respectively). Women with pGDM and BMI < 25 kg/m(2) had significantly higher levels of fasting insulin and HOMA IR than controls (p = 0.008 and 0.05 respectively). Abnormal morphologic findings were more frequent and papillae rectification were 3.3 times more prevalent in pGDM (p = 0.003). Other microvascular parameters did not differ between groups.

CONCLUSION

Cardiovascular risk factors and a microcirculation abnormality (papillae rectification) were significantly increased in young non-diabetic women with pGDM.

The effects of physical activity and physical activity plus diet interventions on body weight in overweight or obese women who are pregnant or in postpartum: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To review the effectiveness of physical activity (PA) and PA plus diet interventions in managing weight among overweight or obese (OW/OB) pregnant or postpartum women.

METHODS

Four databases were searched for randomized controlled studies published between January 2000 and December 2011 that reported weight change outcomes of PA interventions in OW/OB pregnant or postpartum women. PA alone as well as PA plus diet interventions were included.

RESULTS

Of 681 abstracts identified, 11 were included (7 trials with pregnant women and 4 trials with postpartum women). Overall, we found that PA interventions were effective for OW/OB pregnant as well as postpartum women. On average, pregnant women in the intervention groups gained 0.91kg less (95% CI: -1.76, -0.06) compared with those in the usual care groups. Postpartum women in the intervention groups significantly lost more body weight (-1.22kg; 95% CI: -1.89, -0.56) than those in the control groups. In the subgroup analyses by PA intervention types, supervised PA plus diet interventions were the most effective.

CONCLUSIONS

PA plus diet interventions may require more than advice; supervised PA programs or personalized prescription/goals are needed to prevent excessive weight gain for OW/OB pregnant women and excessive weight retention for OW/OB postpartum women.

Prevalence of metabolic syndrome one year after delivery in Finnish women at increased risk for gestational diabetes mellitus during pregnancy

BACKGROUND

Women with a history of gestational diabetes mellitus (GDM) are at increased risk for metabolic syndrome (MeS) after delivery. We studied the prevalence of MeS at one year postpartum among Finnish women who in early pregnancy were at increased risk of developing GDM.

METHODS

This follow-up study is a part of a GDM prevention trial. At one year postpartum, 150 women (mean age 33.1 years, BMI 27.2 kg/m(2)) were evaluated for MeS.

RESULTS

The prevalence of MeS was 18% according tothe International Diabetes Federation (IDF) criteria and 16% according toNational Cholestrol Education Program (NCEP) criteria. Of MeS components, 74% of participants had an increased waist circumference (≥80 cm). Twenty-seven percent had elevated fasting plasma glucose (≥5.6 mmol/L), and 29% had reduced HDL cholesterol (≤1.3 mmol/L). The odds ratio for the occurrence of MeS at one year postpartum was 3.0 (95% CI 1.0-9.2) in those who were overweight before pregnancy compared to normal weight women.

CONCLUSIONS

Nearly one-fifth of the women with an increased risk of GDM in early pregnancy fulfilled the criteria of MeS at one year postpartum. The most important factor associated with MeS was prepregnancy overweight. Weight management before and during pregnancy is important for preventing MeS after delivery.

Cost-effectiveness of lifestyle counselling as primary prevention of gestational diabetes mellitus: findings from a cluster-randomised trial

AIMS

The aim was to evaluate the cost-effectiveness of primary prevention of gestational diabetes mellitus (GDM) through intensified counselling on physical activity, diet, and appropriate weight gain among the risk group.

MATERIALS AND METHODS

The cost-effectiveness analysis was based on data from a cluster-randomised controlled GDM prevention trial carried out in primary health-care maternity clinics in Finland. Women (n = 399) with at least one risk factor for GDM were included. The incremental cost-effectiveness ratio (ICER) was calculated in terms of birth weight, 15D, and perceived health as measured with a visual analogue scale (VAS). A bootstrap technique for cluster-randomised samples was used to estimate uncertainty around a cost-effectiveness acceptability curve.

RESULTS

The mean total cost in the intervention group was €7,763 (standard deviation (SD): €4,511) and in the usual-care group was €6,994 (SD: €4,326, p = 0.14). The mean intervention cost was €141. The difference for costs in the birth-weight group was €753 (95% CI: -250 to 1,818) and in effects for birth weight was 115 g (95% CI: 15 to 222). The ICER for birth weight was almost €7, with 86.7% of bootstrap pairs located in the north-east quadrant, indicating that the intervention was more effective and more expensive in birth weight terms than the usual care was. The data show an 86.7% probability that each gram of birth weight avoided requires an additional cost of €7.

CONCLUSIONS

Intervention was effective for birth weight but was not cost-effective for birth weight, 15D, or VAS when compared to the usual care.

TRIAL REGISTRATION

ISRCTN 33885819.

Overweight, obesity, and neighborhood characteristics among postpartum Latinas

BACKGROUND

Weight gain during the childbearing years and failure to lose pregnancy weight after birth contribute to the development of obesity in Latinas.

DESIGN AND METHODS

Madres para la Salud (Mothers for Health) is a 12-month prospective, randomized controlled trial exploring a social support intervention with moderate-intensity physical activity to effect changes in body fat, systemic and fat tissue inflammation, and depression symptoms in sedentary postpartum Latinas. This paper describes the initial body composition of the sample, social support, and neighborhood contextual correlations of overweight and obese Latina mothers within the first 6 months after birth.

RESULTS

The mean body mass index was 29.68 with 38.56% bioelectrical impedence analysis for body fat. Elements of the environment (e.g., opportunities to walk) received middle or high scores. Access to healthy food was positively related to favorability of the walking environment. Waist-to-hip ratio was uncorrelated with other obesity-related indices.

CONCLUSIONS

The body adiposity of these Latina mothers was coupled with low levels of social support from family and friends and neighborhood characteristics that were unfavorable to walking.

Is intensive counseling in maternity care feasible and effective in promoting physical activity among women at risk for gestational diabetes? Secondary analysis of a cluster randomized NELLI study in Finland

BACKGROUND

Women who are physically active during early pregnancy have notably lower odds of developing gestational diabetes than do inactive women. The purpose of the intervention was to examine whether intensified physical activity (PA) counseling in Finnish maternity care is feasible and effective in promoting leisure-time PA (LTPA) among pregnant women at risk of gestational diabetes.

METHODS

Fourteen municipalities were randomized to intervention (INT) and usual care group (UC). Nurses in INT integrated five PA counseling sessions into routine maternity visits and offered monthly group meetings on PA instructed by physiotherapists. In UC conventional practices were continued. Feasibility evaluation included safety (incidence of PA-related adverse events; questionnaire), realization (timing and duration of sessions, number of sessions missed, attendance at group meetings; systematic record-keeping of the nurses and physiotherapists) and applicability (nurses' views; telephone interview). Effectiveness outcomes were weekly frequency and duration of total and intensity-specific LTPA and meeting PA recommendation for health self-reported at 8-12 (baseline), 26-28 and 36-37 weeks' gestation. Multilevel analysis with adjustments was used in testing for between-group differences in PA changes.

RESULTS

The decrease in the weekly days of total and moderate-to-vigorous-intensity LTPA was smaller in INT (N = 219) than in UC (N = 180) from baseline to the first follow-up (0.1 vs. -1.2, p = 0.040 and -0.2 vs. -1.3, p = 0.016). A similar trend was seen in meeting the PA recommendation (-11%-points vs. -28%-points, p = 0.06). INT did not experience more adverse events classified as warning signs to terminate exercise than UC, counseling was implemented as planned and viewed positively by the nurses.

CONCLUSIONS

Intensified counseling had no effects on the duration of total or intensity-specific weekly LTPA. However, it was able to reduce the decrease in the weekly frequency of total and moderate-to-vigorous-intensity LTPA from baseline to the end of second trimester and was feasibly embedded into routine practices. TR

Health care costs associated with gestational diabetes mellitus among high-risk women--results from a randomised trial

Background

The costs of gestational diabetes mellitus (GDM) screening have been frequently reported, but total GDM-related health care costs compared to the health care costs of women without GDM have not been reported. The aim of this study was to analyse GDM-related health care costs among women with an elevated risk of GDM.

Methods

The study was based on a cluster-randomised GDM prevention trial (N = 848) carried out at maternity clinics, combined with data from the Finnish Medical Birth Register and Care Registers for Social Welfare and Health Care. Costs of outpatient visits to primary and secondary care, cost of inpatient hospital care before and after delivery, the use of insulin, delivery costs and babies’ stay in the neonatal intensive care unit were analysed. Women who developed GDM were compared to those who were not diagnosed with GDM.

Results

Total mean health care costs adjusted for age, body mass index and education were 25.1% higher among women diagnosed with GDM (€6,432 vs. €5,143, p < 0.001) than among women without GDM. The cost of inpatient visits was 44% higher and neonatal intensive care unit use was 49% higher in the GDM group than among women without GDM. The delivery costs were the largest single component in both groups.

Conclusions

A confirmed GDM diagnosis was associated with a significant increase in total health care costs. Effective lifestyle counselling by primary health care providers may offer a means of reducing the high costs of secondary care.

Exercise for pregnant women for preventing gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) affects a significant number of women each year. GDM is associated with a wide range of adverse outcomes for women and their babies. Recent observational studies have found physical activity during normal pregnancy decreases insulin resistance and therefore might help to decrease the risk of developing GDM.

OBJECTIVES

To assess the effects of physical exercise for pregnant women for preventing glucose intolerance or GDM.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 April 2012), ClinicalTrials.gov (2 April 2012) and the WOMBAT Perinatal Trials Registry (2 April 2012).

SELECTION CRITERIA

Randomised and cluster-randomised trials assessing the effects of exercise for preventing pregnancy glucose intolerance or GDM.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies.

MAIN RESULTS

We included five trials with a total of 1115 women and their babies (922 women and their babies contributed outcome data). Four of the five included trials had small sample sizes with one large trial that recruited 855 women and babies. All five included trials had a moderate risk of bias. When comparing women receiving additional exercise interventions with those having routine antenatal care, there was no significant difference in GDM incidence (three trials, 826 women, risk ratio (RR) 1.10, 95% confidence interval (CI) 0.66 to 1.84), caesarean section (two trials, 934 women, RR 1.33, 95% CI 0.97 to 1.84) or operative vaginal birth (two trials, 934 women, RR 0.83, 95% CI 0.58 to 1.17). No trial reported the infant primary outcomes prespecified in the review.None of the five included trials found significant differences in insulin sensitivity. Evidence from one single large trial suggested no significant difference in the incidence of developing pregnancy hyperglycaemia not meeting GDM diagnostic criteria, pre-eclampsia or admission to neonatal ward between the two study groups. Babies born to women receiving exercise interventions had a non-significant trend to a lower ponderal index (mean difference (MD) -0.08 gram x 100 m(3), 95% CI -0.18 to 0.02, one trial, 84 infants). No significant differences were seen between the two study groups for the outcomes of birthweight (two trials, 167 infants, MD -102.87 grams, 95% CI -235.34 to 29.60), macrosomia (two trials, 934 infants, RR 0.91, 95% CI 0.68 to 1.22), or small-for-gestational age (one trial, 84 infants, RR 1.05, 95% CI 0.25 to 4.40) or gestational age at birth (two trials, 167 infants, MD -0.04 weeks, 95% CI -0.37 to 0.29) or Apgar score less than seven at five minutes (two trials, 919 infants, RR 1.00, 95% CI 0.27 to 3.65). None of the trials reported long-term outcomes for women and their babies. No information was available on health services costs.

AUTHORS' CONCLUSIONS

There is limited randomised controlled trial evidence available on the effect of exercise during pregnancy for preventing pregnancy glucose intolerance or GDM. Results from three randomised trials with moderate risk of bias suggested no significant difference in GDM incidence between women receiving an additional exercise intervention and routine care.Based on the limited data currently available, conclusive evidence is not available to guide practice. Larger, well-designed randomised trials, with standardised behavioural interventions are needed to assess the effects of exercise on preventing GDM and other adverse pregnancy outcomes including large-for-gestational age and perinatal mortality. Longer-term health outcomes for both women and their babies and health service costs should be included. Several such trials are in progress. We identified another seven trials which are ongoing and we will consider these for inclusion in the next update of this review.

Effects of dietary counselling on food habits and dietary intake of Finnish pregnant women at increased risk for gestational diabetes - a secondary analysis of a cluster-randomized controlled trial

The incidence of gestational diabetes mellitus (GDM) is increasing and GDM might be prevented by improving diet. Few interventions have assessed the effects of dietary counselling on dietary intake of pregnant women. This study examined the effects of dietary counselling on food habits and dietary intake of Finnish pregnant women as secondary outcomes of a trial primarily aiming at preventing GDM. A cluster-randomized controlled trial was conducted in 14 municipalities in Finland, including 399 pregnant women at increased risk for developing GDM. The intervention consisted of dietary counselling focusing on dietary fat, fibre and saccharose intake at four routine maternity clinic visits. Usual counselling practices were continued in the usual care municipalities. A validated 181-item food frequency questionnaire was used to assess changes in diet from baseline to 26-28 and 36-37 weeks gestation. The data were analysed using multilevel mixed-effects linear regression models. By 36-37 weeks gestation, the intervention had beneficial effects on total intake of vegetables, fruits and berries (coefficient for between-group difference in change 61.6 g day(-1), 95% confidence interval 25.7-97.6), the proportions of high-fibre bread of all bread (7.2% units, 2.5-11.9), low-fat cheeses of all cheeses (10.7% units, 2.6-18.9) and vegetable fats of all dietary fats (6.1% -units, 2.0-10.3), and the intake of saturated fatty acids (-0.67 energy-%-units, -1.16 to -0.19), polyunsaturated fatty acids (0.38 energy-%-units, 0.18-0.58), linoleic acid (764 mg day(-1), 173-1354) and fibre (2.07 g day(-1) , 0.39-3.75). The intervention improved diet towards the recommendations in pregnant women at increased risk for GDM suggesting the counselling methods could be implemented in maternity care.

Strategies to Promote Physical Activity During Pregnancy: A Systematic Review of Intervention Evidence

Physical activity during pregnancy has been associated with significant health benefits, however most women in the United States do not meet current guidelines. This systematic review evaluates evidence for interventions to improve physical activity during pregnancy in order to identify best practices and inform future research. Electronic databases (PubMed, CINAHL, SportDISCUS, Embase, ERIC, Psych Info and ISI Web of Science) were searched in July 2011 for peer-reviewed journal articles. Studies were included if they were English-language randomized control trials that measured the efficacy of an intervention targeted to pregnant women and designed to change physical activity as a primary or secondary outcome. Out of 777 studies identified through the systematic search, nine interventions were identified for inclusion by multiple reviewers. Data was abstracted using an abstraction form modeled after the "Guide to Community Preventive Services." Of the nine interventions included in the review, three reported statistically significant positive results for physical activity. While interventions included a variety of strategies and techniques, none were uniquely associated with positive outcomes. Overall this review suggests that little is known about the efficacy of interventions for physical activity during pregnancy. We provide several recommendations for future research and intervention design.

Interventions for preventing excessive weight gain during pregnancy

BACKGROUND

Excessive weight gain during pregnancy is associated with multiple maternal and neonatal complications. However, interventions to prevent excessive weight gain during pregnancy have not been adequately evaluated.

OBJECTIVES

To evaluate the effectiveness of interventions for preventing excessive weight gain during pregnancy and associated pregnancy complications.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 October 2011) and MEDLINE (1966 to 20 October 2011).

SELECTION CRITERIA

All randomised controlled trials and quasi-randomised trials of interventions for preventing excessive weight gain during pregnancy.

DATA COLLECTION AND ANALYSIS

We assessed for inclusion all potential studies we identified as a result of the search strategy. At least two review authors independently assessed trial quality and extracted data. We resolved discrepancies through discussion. We have presented results using risk ratio (RR) for categorical data and mean difference for continuous data. We analysed data using a fixed-effect model.

MAIN RESULTS

We included 28 studies involving 3976 women; 27 of these studies with 3964 women contributed data to the analyses. Interventions focused on a broad range of interventions. However, for most outcomes we could not combine data in a meta-analysis, and where we did pool data, no more than two or three studies could be combined for a particular intervention and outcome. Overall, results from this review were mainly not statistically significant, and where there did appear to be differences between intervention and control groups, results were not consistent. For women in general clinic populations one (behavioural counselling versus standard care) of three interventions examined was associated with a reduction in the rate of excessive weight gain (RR 0.72, 95% confidence interval 0.54 to 0.95); for women in high-risk groups no intervention appeared to reduce excess weight gain. There were inconsistent results for mean weight gain (reported in all but one of the included studies). We found a statistically significant effect on mean weight gain for five interventions in the general population and for two interventions in high-risk groups.Most studies did not show statistically significant effects on maternal complications, and none reported significant effects on adverse neonatal outcomes.

AUTHORS' CONCLUSIONS

There is not enough evidence to recommend any intervention for preventing excessive weight gain during pregnancy, due to the significant methodological limitations of included studies and the small observed effect sizes. More high-quality randomised controlled trials with adequate sample sizes are required to evaluate the effectiveness of potential interventions.

Prediction and prevention of the macrosomic fetus

Fetal macrosomia is associated with significant maternal and neonatal morbidity. In the long term, infants who are large for gestational age are more likely than other infants to be obese in childhood, adolescence and early adulthood, and are inherently at higher risk of cardiovascular and metabolic complications in adulthood. With over one billion adults in the world now overweight and more than 600 million clinically obese, preventing the vicious cycle effect of fetal macrosomia and childhood obesity is an increasingly pertinent issue. Fetal growth is determined by a complex interplay of various genetic and environmental influences. Consequently the prediction of pregnancies at risk of pathological overgrowth is difficult. Many risk factors for fetal macrosomia, such as maternal obesity and advanced maternal age, are also conversely associated with intrauterine growth restriction. Sonographic detection of fetal macrosomia is notoriously fraught with difficulties, with dozens of formulas for estimated fetal weight proposed but few with sufficient sensitivity to alter clinical practice. This calls into question policies of elective delivery based on projected estimated fetal weight cut-offs alone. More recently the identification of markers of fetal adiposity and maternal serum biomarkers are being investigated to improve the antenatal detection of the large for gestational age fetus. Prevention of fetal macrosomia is entirely dependent upon correct identification of those at risk. Maternal weight, gestational weight gain and glycaemic control are the risk factors for fetal macrosomia that are most amenable to intervention, and have potential maternal health benefits beyond pregnancy and childbirth. The ideal method of optimising maternal weight and glucose homeostasis is yet to be elucidated, though a number of promising advances are recently being reported. In this review we outline the contemporary evidence for the prediction and prevention of fetal macrosomia, which is indeed a contemporary dilemma.

Iron intake, haemoglobin and risk of gestational diabetes: a prospective cohort study

OBJECTIVE

To investigate the possible association between total daily iron intake during pregnancy, haemoglobin in early pregnancy and the risk of gestational diabetes mellitus (GDM) in women at increased risk of GDM.

DESIGN

A prospective cohort study (based on a cluster-randomised controlled trial, where the intervention and the usual care groups were combined).

SETTING

Primary healthcare maternity clinics in 14 municipalities in south-western Finland.

PARTICIPANTS

399 Pregnant women who were at increased risk of GDM participated in a GDM prevention trial and were followed throughout pregnancy.

MAIN OUTCOME MEASUREMENTS

The main outcome was GDM diagnosed with oral glucose tolerance test at 26-28 weeks' gestation or based on a diagnosis recorded in the Finnish Medical Birth registry. Data on iron intake was collected using a 181-item food frequency questionnaire and separate questions for supplement use at 26-28 weeks' gestation.

RESULTS

GDM was diagnosed in 72 women (18.1%) in the study population. The OR for total iron intake as a continuous variable was 1.006 (95% CI 1.000 to 1.011; p=0.038) after adjustment for body mass index, age, diabetes in first-degree or second-degree relatives, GDM or macrosomia in earlier pregnancy, total energy intake, dietary fibre, saturated fatty acids and total gestational weight gain. Women in the highest fifth of total daily iron intake had an adjusted OR of 1.66 (95% CI 0.84 to 3.30; p=0.15) for GDM. After excluding participants with low haemoglobin levels (≤120 g/l) already in early pregnancy the adjusted OR was 2.35 (95% CI 1.13 to 4.92; p=0.023).

CONCLUSIONS

Our results suggest that high iron intake during pregnancy increases the risk of GDM especially in women who are not anaemic in early pregnancy and who are at increased risk of GDM. These findings suggest that routine iron supplementation should be reconsidered in this risk group of women.

Cost of gestational diabetes-related antenatal visits in health care based on the Finnish Medical Birth Register

The aim was to evaluate frequency and costs of antenatal health care visits related to risk of gestational diabetes (GDM) using Birth Register. Costs among all GDM risk groups were 10-41% larger than non-risk groups. Primary health care is needed to reduce special health care costs related to GDM.

Antepartum A1C, maternal diabetes outcomes, and selected offspring outcomes: an epidemiological review

Between 1989 and 2004, the prevalence of gestational diabetes mellitus (GDM) in the United States increased by 122%. Glycated haemoglobin, as measured by haemoglobin A1C (A1C), can potentially identify pregnant women at high risk for adverse outcomes associated with GDM including macrosomia and post-partum glucose intolerance. Our objective was to systematically review the literature with respect to A1C levels during pregnancy and associated maternal and offspring outcomes. We used MEDLINE to identify relevant publications from 1975 to 2009. We included articles if they met the following criteria: original full text articles in English; primary exposure of antepartum A1C; women with GDM at baseline or who developed GDM during the study; primary outcome of GDM, insulin use, post-partum abnormal glucose or type 2 diabetes (T2DM), birthweight, macrosomia or large for gestational age. Case series and case reports were excluded. Twenty studies met our criteria. A1C at GDM diagnosis was positively associated with post-partum abnormal glucose. Women with post-partum T2DM or impaired glucose tolerance had mean A1C at GDM diagnosis higher than those with normal post-partum glucose (P ≤ 0.002) and a 1% increase in A1C at GDM diagnosis was associated with 2.36 times higher odds of post-partum abnormal glucose 6 weeks after delivery [95% confidence interval 1.19, 4.68]. The association of A1C and birthweight varied substantially between studies, with correlation coefficients ranging from 0.11 to 0.51. A1C, a less burdensome and costly measure than an oral glucose tolerance test, appears to be an attractive measure for identifying women at high risk of adverse outcomes associated with GDM.

Primary prevention of gestational diabetes mellitus and large-for-gestational-age newborns by lifestyle counseling: a cluster-randomized controlled trial

BACKGROUND

Our objective was to examine whether gestational diabetes mellitus (GDM) or newborns' high birthweight can be prevented by lifestyle counseling in pregnant women at high risk of GDM.

METHOD AND FINDINGS

We conducted a cluster-randomized trial, the NELLI study, in 14 municipalities in Finland, where 2,271 women were screened by oral glucose tolerance test (OGTT) at 8-12 wk gestation. Euglycemic (n = 399) women with at least one GDM risk factor (body mass index [BMI] ≥ 25 kg/m(2), glucose intolerance or newborn's macrosomia (≥ 4,500 g) in any earlier pregnancy, family history of diabetes, age ≥ 40 y) were included. The intervention included individual intensified counseling on physical activity and diet and weight gain at five antenatal visits. Primary outcomes were incidence of GDM as assessed by OGTT (maternal outcome) and newborns' birthweight adjusted for gestational age (neonatal outcome). Secondary outcomes were maternal weight gain and the need for insulin treatment during pregnancy. Adherence to the intervention was evaluated on the basis of changes in physical activity (weekly metabolic equivalent task (MET) minutes) and diet (intake of total fat, saturated and polyunsaturated fatty acids, saccharose, and fiber). Multilevel analyses took into account cluster, maternity clinic, and nurse level influences in addition to age, education, parity, and prepregnancy BMI. 15.8% (34/216) of women in the intervention group and 12.4% (22/179) in the usual care group developed GDM (absolute effect size 1.36, 95% confidence interval [CI] 0.71-2.62, p = 0.36). Neonatal birthweight was lower in the intervention than in the usual care group (absolute effect size -133 g, 95% CI -231 to -35, p = 0.008) as was proportion of large-for-gestational-age (LGA) newborns (26/216, 12.1% versus 34/179, 19.7%, p = 0.042). Women in the intervention group increased their intake of dietary fiber (adjusted coefficient 1.83, 95% CI 0.30-3.25, p = 0.023) and polyunsaturated fatty acids (adjusted coefficient 0.37, 95% CI 0.16-0.57, p < 0.001), decreased their intake of saturated fatty acids (adjusted coefficient -0.63, 95% CI -1.12 to -0.15, p = 0.01) and intake of saccharose (adjusted coefficient -0.83, 95% CI -1.55 to -0.11, p  =  0.023), and had a tendency to a smaller decrease in MET minutes/week for at least moderate intensity activity (adjusted coefficient 91, 95% CI -37 to 219, p = 0.17) than women in the usual care group. In subgroup analysis, adherent women in the intervention group (n = 55/229) had decreased risk of GDM (27.3% versus 33.0%, p = 0.43) and LGA newborns (7.3% versus 19.5%, p = 0.03) compared to women in the usual care group.

CONCLUSIONS

The intervention was effective in controlling birthweight of the newborns, but failed to have an effect on maternal GDM.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN33885819. Please see later in the article for the Editors' Summary.

Obesity and diabetes in mothers and their children: can we stop the intergenerational cycle?

Obesity prevalence in the United States has reached an alarming level. Consequently, more young women are entering pregnancy with body mass indices of at least 30 kg/m(2). While higher maternal weight entering pregnancy is related to several adverse pregnancy outcomes, some of the strongest and most compelling data to date have linked prepregnancy obesity to gestational diabetes mellitus (GDM). The mechanisms by which excess maternal weight influences metabolic dysfunction in pregnancy are similar to those in obese nonpregnant women; adipocytes are metabolically active and release a number of hormones implicated in insulin resistance. Heavier mothers are also more likely to have higher glucose levels that do not exceed the cutoff for GDM, but nevertheless predict poor perinatal outcomes. Longer-term complications of GDM include increased risk of maternal type 2 diabetes and offspring obesity. Promising intervention studies to decrease the intergenerational cycle of obesity and diabetes are currently underway.

Physical activity and gestational weight gain: a meta-analysis of intervention trials

BACKGROUND

high gestational weight gain (GWG) has been found to be associated with a number of adverse perinatal and long-term outcomes.

OBJECTIVES

we aimed to perform a systematic review and meta-analysis to find out whether physical activity in pregnancy might help avoid high GWG.

SEARCH STRATEGY

a literature search in relevant databases and an additional search by hand through bibliographies of various publications were performed.

SELECTION CRITERIA

we included randomised controlled trials on healthy women, with increased physical activity as the only intervention. GWG had to be documented for the intervention and control group separately.

DATA COLLECTION AND ANALYSIS

two reviewers independently extracted data and performed quality assessment. Data from the included trials were combined using a random-effects model. The effect size was expressed as mean difference (MD).

MAIN RESULTS

of 1380 studies identified, 12 trials met the inclusion criteria. In seven trials, GWG was lower in the exercise group compared with the control group, whereas five trials showed a lower GWG in the control groups. The meta-analysis resulted in an MD of GWG of -0.61 (95% CI: -1.17, -0.06), suggesting less GWG in the intervention groups compared with the control groups. We found no indication for publication bias or dose effects.

AUTHOR'S CONCLUSIONS

in summary, our analyses suggest that physical activity during pregnancy might be successful in restricting GWG.