Effect of a low-glycemic-index diet during pregnancy on obstetric outcomes

Intake of carbohydrates during pregnancy in obese women is associated with fat mass in the newborn offspring

BACKGROUND

Transmission of obesity across generations is of concern. Offspring of obese women have short- and long-term increased morbidities. A high intake of carbohydrate during pregnancy combined with impaired glucose tolerance is postulated to result in high birth weight, which is linked to subsequent metabolic disease.

OBJECTIVE

The objective was to examine the association between carbohydrate intake in obese pregnant women and their offspring's body composition.

DESIGN

Secondary analyses were performed in an observational setting of 222 pregnant women with a pregestational BMI (in kg/m(2)) ≥30 participating in a randomized controlled trial. Diet was assessed at gestational weeks 11-14 and 36-37 by using a semiquantitative food-frequency questionnaire. Body composition in the offspring was assessed at birth by dual-energy X-ray absorptiometry. Relative fat mass (%) was the primary outcome. Absolute measures (total fat, abdominal fat, and lean body mass) were secondary outcomes.

RESULTS

Mean ± SD weight and absolute and relative fat mass in the offspring at birth were 3769 ± 542 g, 436 ± 214 g, and 11% ± 4%, respectively. Maternal intake of digestible carbohydrates was associated with the offspring's relative fat mass in late (P-trend = 0.006) but not early (P-trend = 0.15) pregnancy. A comparison of mothers in the highest (median: 238 g/d) compared with the lowest (median: 188 g/d) quartile of digestible carbohydrate intake showed a mean adjusted higher value in the offspring's relative fat mass of 2.1% (95% CI: 0.6%, 3.7%), which corresponded in absolute terms to a 103-g (95% CI: 27, 179-g) higher fat mass. Abdominal fat mass was also higher. In a strata of women with well-controlled glucose (2-h glucose values ≤6.6 mmol/L), no association between carbohydrate intake and offspring fat mass was observed, but the associations became significant and increased in strength with higher intolerance (strata with 2-h glucose values between 6.7-7.7 and ≥7.8 mmol/L).

CONCLUSION

In obese women, even those without gestational diabetes but with impaired glucose tolerance, a lower carbohydrate intake at moderate levels in late gestation is associated with a lower fat mass in their offspring at birth. The TOP study was registered at clinicaltrials.gov as NCT01345149.

[Prevention of shoulder dystocia risk factors before delivery]

OBJECTIVE

To determine whether it is possible to prevent the occurrence of risk factors for shoulder dystocia before or during pregnancy.

METHODS

The PubMed database, the Cochrane Library and the recommendations from the French and foreign obstetrical societies or colleges have been consulted. Studied measures were exercise before or during pregnancy, dietary management, and gestational diabetes management in obese and non-obese patients.

RESULTS

No study has proven that the correction of these risk factors (except gestational diabetes) would reduce the risk of shoulder dystocia. In the general population, physical exercise is recommended either before or during pregnancy to reduce the risk of gestational diabetes (physical activity before pregnancy) (grade B), fetal macrosomia (grade C) or maternal weight gain during pregnancy (grade C). No dietary regimen is recommended to reduce these issues (grade B). In overweight or obese (body mass index [BMI]>25), physical activity coupled with dietary management is recommended (grade A) because it reduces fetal macrosomia (EL1). In addition, it allows a modest reduction in maternal weight gain during pregnancy (EL2), but did have an effect on the occurrence of gestational diabetes (EL1). In case of gestational diabetes, diabetes care is recommended (diabetic diet, glucose monitoring, insulin if needed) (grade A) as it reduces the risk of macrosomia and shoulder dystocia (EL1). The recommended weight gain during pregnancy is 11.5 kg to 16 kg for normal BMI patients (grade B). Obese patients should be aware of the importance of controlling their weight gain during pregnancy (professional consensus). It is recommended that patients regain their pre-conception weight, and ideally a BMI between 18 and 25 kg/m(2), 6 months postpartum (grade B) to reduce the risk of gestational diabetes and macrosomia in a subsequent pregnancy (EL2).

CONCLUSION

Physical activity is recommended before and during pregnancy to reduce the occurrence of risk factors for shoulder dystocia. In obese patients, physical activity should be coupled with dietary measures to reduce fetal macrosomia and weight gain during pregnancy.

Intake of Sweets, Snacks and Soft Drinks Predicts Weight Gain in Obese Pregnant Women: Detailed Analysis of the Results of a Randomised Controlled Trial

BACKGROUND

Lifestyle interventions targeting obese pregnant women often result in modest reduction in gestational weight gain, pregnancy complications and related risk factors. Examining adherence to the intervention can, however, provide valuable information on the importance of the different factors targeted.

OBJECTIVE

To evaluate improvements and relevance of different dietary factors targeted with respect to gestational weight gain in a 3-arm Randomised Controlled Trial (n=342) among obese pregnant women with BMI≥30 kg/m2.

METHODS

Randomisation 1:1:1 to either hypocaloric Mediterranean type of diet and physical activity intervention (D+PA); physical activity intervention alone (PA); or control (C). Diet was assessed at baseline (weeks 11-14) and endpoint (weeks 36-37) using a validated food frequency questionnaire.

RESULTS

During the intervention women in the D+PA group significantly lowered their intakes of added sugars and saturated fat and increased their protein intake by ~1% of total energy compared to controls. Of these dietary variables only intakes of added sugar appeared to be related to GWG, while no association was observed for saturated fat or protein. Further analyses revealed that foods that contributed to intake of added sugars, including sweets, snacks, cakes, and soft drinks were strongly associated with weight gain, with women consuming sweets ≥2/day having 5.4 kg (95% CI 2.1-8.7) greater weight gain than those with a low (<1wk) intake. The results for soft drinks were more conflicting, as women with high weight gain tended to favour artificially sweetened soft drinks.

CONCLUSION

In our sample of obese pregnant women, craving for sweets, snacks, and soft drinks strongly predicts GWG. Emphasis on reducing intakes of these foods may be more relevant for limiting gestational weight gain than encouraging strict compliance to more specific diets.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01345149.

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.

Antenatal dietary education and supplementation to increase energy and protein intake

BACKGROUND

Gestational weight gain is positively associated with fetal growth, and observational studies of food supplementation in pregnancy have reported increases in gestational weight gain and fetal growth.

OBJECTIVES

To assess the effects of education during pregnancy to increase energy and protein intake, or of actual energy and protein supplementation, on energy and protein intake, and the effect on maternal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015), reference lists of retrieved studies and contacted researchers in the field.

SELECTION CRITERIA

Randomised controlled trials of dietary education to increase energy and protein intake, or of actual energy and protein supplementation, during pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data and checked for accuracy. Extracted data were supplemented by additional information from the trialists we contacted.

MAIN RESULTS

We examined 149 reports corresponding to 65 trials. Of these trials, 17 were included, 46 were excluded, and two are ongoing. Overall, 17 trials involving 9030 women were included. For this update, we assessed methodological quality of the included trials using the standard Cochrane criteria (risk of bias) and the GRADE approach. The overall risk of bias was unclear. Nutritional education (five trials, 1090 women) Women given nutritional education had a lower relative risk of having a preterm birth (two trials, 449 women) (risk ratio (RR) 0.46, 95% CI 0.21 to 0.98, low-quality evidence), and low birthweight (one trial, 300 women) (RR 0.04, 95% CI 0.01 to 0.14). Head circumference at birth was increased in one trial (389 women) (mean difference (MD) 0.99 cm, 95% CI 0.43 to 1.55), while birthweight was significantly increased among undernourished women in two trials (320 women) (MD 489.76 g, 95% CI 427.93 to 551.59, low-quality evidence), but did not significantly increase for adequately nourished women (MD 15.00, 95% CI -76.30 to 106.30, one trial, 406 women). Protein intake increased significantly (three trials, 632 women) (protein intake: MD +6.99 g/day, 95% CI 3.02 to 10.97). No significant differences were observed on any other outcomes such as neonatal death (RR 1.28, 95% CI 0.35 to 4.72, one trial, 448 women, low-quality evidence), stillbirth (RR 0.37, 95% CI 0.07 to 1.90, one trial, 431 women, low-quality evidence), small-for-gestational age (RR 0.97, 95% CI 0.45 to 2.11, one trial, 404 women, low-quality evidence) and total gestational weight gain (MD -0.41, 95% CI -4.41 to 3.59, two trials, 233 women). There were no data on perinatal death. Balanced energy and protein supplementation (12 trials, 6705 women)Risk of stillbirth was significantly reduced for women given balanced energy and protein supplementation (RR 0.60, 95% CI 0.39 to 0.94, five trials, 3408 women, moderate-quality evidence), and the mean birthweight was significantly increased (random-effects MD +40.96 g, 95% CI 4.66 to 77.26, Tau² = 1744, I² = 44%, 11 trials, 5385 women, moderate-quality evidence). There was also a significant reduction in the risk of small-for-gestational age (RR 0.79, 95% CI 0.69 to 0.90, I² = 16%, seven trials, 4408 women, moderate-quality evidence). No significant effect was detected for preterm birth (RR 0.96, 95% CI 0.80 to 1.16, five trials, 3384 women, moderate-quality evidence) or neonatal death (RR 0.68, 95% CI 0.43 to 1.07, five trials, 3381 women, low-quality evidence). Weekly gestational weight gain was not significantly increased (MD 18.63, 95% CI -1.81 to 39.07, nine trials, 2391 women, very low quality evidence). There were no data reported on perinatal death and low birthweight. High-protein supplementation (one trial, 1051 women)High-protein supplementation (one trial, 505 women), was associated with a significantly increased risk of small-for-gestational age babies (RR 1.58, 95% CI 1.03 to 2.41, moderate-quality evidence). There was no significant effect for stillbirth (RR 0.81, 95% CI 0.31 to 2.15, one trial, 529 women), neonatal death (RR 2.78, 95% CI 0.75 to 10.36, one trial, 529 women), preterm birth (RR 1.14, 95% CI 0.83 to 1.56, one trial, 505 women), birthweight (MD -73.00, 95% CI -171.26 to 25.26, one trial, 504 women) and weekly gestational weight gain (MD 4.50, 95% CI -33.55 to 42.55, one trial, 486 women, low-quality evidence). No data were reported on perinatal death. Isocaloric protein supplementation (two trials, 184 women)Isocaloric protein supplementation (two trials, 184 women) had no significant effect on birthweight (MD 108.25, 95% CI -220.89 to 437.40) and weekly gestational weight gain (MD 110.45, 95% CI -82.87 to 303.76, very low-quality evidence). No data reported on perinatal mortality, stillbirth, neonatal death, small-for-gestational age, and preterm birth.

AUTHORS' CONCLUSIONS

This review provides encouraging evidence that antenatal nutritional education with the aim of increasing energy and protein intake in the general obstetric population appears to be effective in reducing the risk of preterm birth, low birthweight, increasing head circumference at birth, increasing birthweight among undernourished women, and increasing protein intake. There was no evidence of benefit or adverse effect for any other outcome reported.Balanced energy and protein supplementation seems to improve fetal growth, and may reduce the risk of stillbirth and infants born small-for-gestational age. High-protein supplementation does not seem to be beneficial and may be harmful to the fetus. Balanced-protein supplementation alone had no significant effects on perinatal outcomes.The results of this review should be interpreted with caution. The risk of bias was either unclear or high for at least one category examined in several of the included trials, and the quality of the evidence was low for several important outcomes. Also, as the anthropometric characteristics of the general obstetric population is changing, those developing interventions aimed at altering energy and protein intake should ensure that only those women likely to benefit are included. Large, well-designed randomised trials are needed to assess the effects of increasing energy and protein intake during pregnancy in women whose intake is below recommended levels.

Prevention of gestational diabetes in pregnant women with risk factors for gestational diabetes: a systematic review and meta-analysis of randomised trials

BACKGROUND

Gestational diabetes mellitus can be defined as 'glucose intolerance or hyperglycaemia with onset or first recognition during pregnancy.'

OBJECTIVE

The objective of our systematic review was to see if there was any intervention that could be used for primary prevention of gestational diabetes mellitus in women with risk factors for gestational diabetes mellitus.

SEARCH STRATEGY

Major databases were searched from 1966 to Aug 2012 without language restriction.

SELECTION CRITERIA

Randomised trials comparing intervention with standard care in women with risk factors for gestational diabetes were included. Meta-analysis was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. The primary outcome assessed was the incidence of gestational diabetes.

DATA COLLECTION AND ANALYSIS

Data from included trials were extracted independently by two authors and analysed using Rev-Man 5.

MAIN RESULTS

A total of 2422 women from 14 randomised trials were included; which compared diet (four randomised trials), exercise (three randomised trials), lifestyle changes (five randomised trials) and metformin (two randomised trials) with standard care in women with risk factors for gestational diabetes mellitus. Dietary intervention was associated with a statistically significantly lower incidence of gestational diabetes (Odds ratio 0.33, 95% CI 0.14 to 0.76) and gestational hypertension (Odds ratio 0.28, 95% CI 0.09, 0.86) compared to standard care. There was no statistically significant difference in the incidence of gestational diabetes mellitus or in the secondary outcomes with exercise, lifestyle changes or metformin use compared to standard care.

CONCLUSIONS

The use of dietary intervention has shown a statistically significantly lower incidence of gestational diabetes mellitus and gestational hypertension compared to standard care in women with risk factors for gestational diabetes mellitus.

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.

Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes

OBJECTIVE

Diet is the cornerstone treatment of patients with gestational diabetes mellitus (GDM), but its role in maternal and newborn outcomes has been scarcely studied. The purpose of this study was to analyze the efficacy of dietary interventions on maternal or newborn outcomes in patients with GDM.

RESEARCH DESIGN AND METHODS

A systematic review and meta-analysis of randomized clinical trials (RCTs) of dietary intervention in GDM or pregnancy with hyperglycemia was performed. MEDLINE, Embase, ClinicalTrials.gov, Cochrane, and Scopus were searched through to March 2014. The main evaluated maternal outcomes were proportion of patients using insulin and proportion of cesarean delivery; the newborn outcomes were proportion of macrosomia and hypoglycemia and newborn weight.

RESULTS

From 1,170 studies, nine RCTs, including 884 women aged 31.5 years (28.7-33.2) with 27.4 weeks (24.1-30.3) of gestation, were eligible. We divided the RCTs according to the type of dietary intervention: low glycemic index (GI) (n = 4; 257 patients), total energy restriction (n = 2; 425 patients), low carbohydrates (n = 2; 182 patients), and others (n = 1; 20 patients). Diet with low GI reduced the proportion of patients who used insulin (relative risk 0.767 [95% CI 0.597, 0.986]; P = 0.039) and the newborn birth weight (weight mean differences -161.9 g [95% CI -246.4, -77.4]; P = 0.000) as compared with control diet. Total restriction and low carbohydrate diets did not change either maternal or newborn outcomes.

CONCLUSIONS

A low GI diet was associated with less frequent insulin use and lower birth weight than control diets, suggesting that it is the most appropriate dietary intervention to be prescribed to patients with GDM.

The effects of antenatal dietary and lifestyle advice for women who are overweight or obese on maternal diet and physical activity: the LIMIT randomised trial

BACKGROUND

Overweight and obesity is a significant health concern during pregnancy. Our aim was to investigate the effect of providing antenatal dietary and lifestyle advice to women who are overweight or obese on components of maternal diet and physical activity.

METHODS

We conducted a randomised controlled trial, in which pregnant women with a body mass index≥25 kg/m2, and singleton gestation between 10(+0) to 20(+0) weeks were recruited and randomised to Lifestyle Advice (involving a comprehensive dietary and lifestyle intervention over their pregnancy) or Standard Care. Within the intervention group, we conducted a nested randomised trial in which a subgroup of women were further randomised to receive access to supervised group walking sessions in addition to the standard information presented during the intervention contacts (the Walking group) or standard information only. The outcome measures were maternal dietary intake, (including food groups, macronutrient and micronutrient intake, diet quality (using the Healthy Eating Index; HEI), dietary glycaemic load, and glycaemic index) and maternal physical activity. Women completed the Harvard Semi-Structured Food Frequency Questionnaire, and the Short Questionnaire to Assess Health-enhancing Physical Activity (SQUASH), at trial entry, 28 and 36 weeks' gestational age, and 4 months postpartum. Analyses were performed on an intention-to-treat basis, using linear mixed effects models with adjustment for the stratification variables.

RESULTS

Women randomised to Lifestyle Advice demonstrated a statistically significant increase in the number of servings of fruit and vegetables consumed per day, as well as increased consumption of fibre, and reduced percentage energy intake from saturated fats (P<0.05 for all). Maternal HEI was significantly improved at both 28 (73.35±6.62 versus 71.86±7.01; adjusted difference in means 1.58; 95% CI 0.89 to 2.27; P<0.0001) and 36 (72.95±6.82 versus 71.17±7.69; adjusted difference in means 1.77; 95% CI 1.01 to 2.53; P<0.0001) weeks. There were no differences in dietary glycaemic index or glycaemic load. Women randomised to Lifestyle Advice also demonstrated greater total physical activity (adjusted difference in means 359.76 metabolic equivalent task units (MET) minutes/week; 95% CI 74.87 to 644.65; P=0.01) compared with women receiving Standard Care. The supervised walking group was poorly utilised.

CONCLUSIONS

For women who are overweight or obese, antenatal lifestyle advice improves maternal diet and physical activity during pregnancy. Please see related articles: http://www.biomedcentral.com/1741-7015/12/163 and http://www.biomedcentral.com/1741-7015/12/201.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry ( ACTRN12607000161426).

Impact of maternal nutrition on pregnancy outcome--does it matter what pregnant women eat?

Pregnancy presents a unique époque in life with considerable potential to influence not only maternal health but also the health of the next generation. Nutritional interventions in pregnancy can influence maternal, foetal and infant health. This chapter describes the findings of a large randomised controlled trial on the impact of a low glycaemic index diet on maternal and foetal health and discusses areas of future research in this important area.

Correlations Among Parental and Neonatal Anthropometric Parameters, Feeding Practices and Infant Obesity

BACKGROUND AND AIMS

Infant and adult obesity is becoming a real public health concern in Romania, similar to other countries of the European Union. Maternal obesity and excessive weight gain during pregnancy are proven risk factors for the obesity of the child. The protective role of the breastfeeding against obesity has also been demonstrated. The most important issue is whether the choice of a milk formula with the right protein composition could or not protect the newborn from becoming a future obese infant and child. Our study aims to describe the characteristics of a group of macrosomic newborns, in relation to the mothers' weight gain during pregnancy, mode of delivery, birth weight, complications at birth, time of first feeding and type of feeding during maternity stay.

PATIENTS AND METHODS

We conducted a retrospective study on 179 newborns with birth weights >4000 grams, born over a period of three months (March-May) in 6 large maternity hospitals in Romania.

RESULTS

the newborns had a mean gestational age of 39.5 weeks and a mean birth weight of 4195 grams. Male newborns were prevalent (74%). More than half were born by Cesarian section and had Apgar scores with a median of 9. Macrosomes are prone to complications at birth and in our study those were mainly hypoglycemia and birth trauma. Time at first feeding was 95 minutes (mean), with a high percentage of formula/mixed feeding (68%).

CONCLUSION

Macrosomia itself attracts the risk of birth by cesarean section (54% of study group), birth trauma and a low rate of exclusive breast milk feeding (32% of study group) at discharge.

Maternal dietary glycemic index and glycemic load in early pregnancy are associated with offspring adiposity in childhood: the Southampton Women's Survey

BACKGROUND

Maternal hyperglycemia in pregnancy is associated with greater adiposity in offspring. The glycemic index (GI) and glycemic load (GL) describe the glycemic response to carbohydrate ingestion. However, the influence of maternal dietary GI and GL in pregnancy on childhood adiposity is unknown.

OBJECTIVE

We examined relations of maternal dietary GI and GL in early and late pregnancy with offspring body composition.

DESIGN

A total of 906 mother-child pairs from the prospective cohort the Southampton Women's Survey were included. Children underwent dual-energy X-ray absorptiometry measurements of body composition at birth and 4 and 6 y of age. Log-transformed fat mass and lean mass were standardized with a mean (±SD) of 0 ± 1. Maternal dietary GI and GL were assessed at 11 and 34 wk of gestation by using an administered food-frequency questionnaire.

RESULTS

After control for potential confounders, both maternal dietary GI and GL in early pregnancy were positively associated with fat mass at 4 and 6 y of age [fat mass SDs per 10-unit GI increase: β = 0.43 (95% CI: 0.06, 0.80), P = 0.02 at 4 y of age; β = 0.40 (95% CI: 0.10, 0.70), P = 0.01 at 6 y of age; fat mass SDs per 50-unit GL increase: β = 0.43 (95% CI: 0.19, 0.67), P < 0.001 at 4 y of age; β = 0.27 (95% CI: 0.07, 0.47), P = 0.007 at 6 y of age]. In contrast, there were no associations between maternal dietary GI or GL in late pregnancy and offspring fat mass at these ages. Maternal dietary GI and GL were not associated with fat mass at birth or offspring lean mass at any of the ages studied.

CONCLUSION

Higher maternal dietary GI and GL in early pregnancy are associated with greater adiposity in childhood.

Maternal diet and weight at 3 months postpartum following a pregnancy intervention with a low glycaemic index diet: results from the ROLO randomised control trial

Pregnancy increases the risk of being overweight at a later time period, particularly when there is excessive gestational weight gain. There remains a paucity of data into the effect of low glycaemic index (GI) pregnancy interventions postpartum.

AIM

To examine the impact of a low glycaemic index diet during pregnancy on maternal diet 3 months postpartum.

METHODOLOGY

This analysis examined the diet, weight and lifestyle of 460 participants of the ROLO study 3 months postpartum. Questionnaires on weight, physical activity, breastfeeding, supplement use, food label reading and dietary habits were completed.

RESULTS

The intervention group had significantly greater weight loss from pre-pregnancy to 3 months postpartum than the control group (1.3 vs. 0.1 kg, p = 0.022). The intervention group reported greater numbers following a low glycaemic index diet (p < 0.001) and reading food labels (p = 0.032) and had a lower glycaemic load (GL) (128 vs. 145, p = 0.014) but not GI (55 vs. 55, p = 0.809) than controls.

CONCLUSIONS

Low GI dietary interventions in pregnancy result in improved health-behaviours and continued reported compliance at 3 months postpartum possibly through lower dietary GL as a result of portion control. Greater levels of weight loss from pre-pregnancy to 3 months postpartum in the intervention group may have important positive implications for overweight and obesity.

High birth weight is associated with obesity and increased carotid wall thickness in young adults: the cardiovascular risk in young Finns study

OBJECTIVE

There is some evidence that people born with high birth weight may be at increased risk of cardiovascular disease in adulthood. Details of the underlying mechanisms remain unknown. We sought to determine whether people born large for gestational age have poor arterial health, increased adiposity, and a poor cardiovascular risk factor profile.

APPROACH AND RESULTS

Carotid intima-media thickness, brachial flow-mediated dilatation, and cardiovascular risk factors were compared between young adults (24-45 years) born at term who were large for gestational age (birth weight >90th percentile; n=171), and a control group with normal birth weight (50-75th percentile; n=525), in the Cardiovascular Risk in Young Finns Study. Those born large for gestational age had higher body mass index throughout childhood, adolescence, and as young adults (26.4 kg/m(2) [SD 4.9], versus normal birth weight 25.1 kg/m(2) [SD 4.6]; P=0.002), and 2-fold greater risk of obesity. Other cardiovascular risk factors and arterial function did not differ; however, carotid intima-media thickness was increased in people born large for gestational age (0.60 mm [SD 0.09], versus normal birth weight 0.57 mm [SD 0.09]; P=0.003), independent of cardiovascular risk factors (P=0.001 after adjustment). Both obesity and high birth weight were independently associated with carotid intima-media thickness in a graded and additive fashion.

CONCLUSIONS

Young adults born large for gestational age are more likely to be obese, yet have an otherwise healthy cardiovascular risk profile. Nonetheless, they have increased carotid intima-media thickness, a marker of subclinical atherosclerosis, consistent with an increased risk of cardiovascular disease.

Pregnancy and Glycemic Index Outcomes study: effects of low glycemic index compared with conventional dietary advice on selected pregnancy outcomes

BACKGROUND

Eating carbohydrate foods with a high glycemic index (GI) has been postulated to result in fetoplacental overgrowth and higher infant body fat. A diet with a low glycemic index (LGI) has been shown to reduce birth percentiles and the ponderal index (PI).

OBJECTIVES

We investigated whether offering LGI dietary advice at the first antenatal visit would result in a lower fetal birth weight, birth percentile, and PI than providing healthy eating (HE) advice. This advice had to be presented within the resources of routine antenatal care.

DESIGN

The Pregnancy and Glycemic Index Outcomes study was a 2-arm, parallel-design, randomized, controlled trial that compared the effects of LGI dietary advice with HE advice on pregnancy outcomes. Eligible volunteers who attended for routine antenatal care at <20 wk of gestation were randomly assigned to either group.

RESULTS

A total of 691 women were enrolled, and 576 women had final data considered. In the LGI group, the GI was reduced from a mean (± SEM) of 56 ± 0.3 at enrollment to 52 ± 0.3 (P < 0.001) at the final assessment. There were no significant differences in primary outcomes of fetal birth weight, birth percentile, or PI. In a multivariate regression analysis, the glycemic load was the only significant dietary predictor (P = 0.046) of primary outcomes but explained <1% of all variation.

CONCLUSION

A low-intensity dietary intervention with an LGI diet compared with an HE diet in pregnancy did not result in any significant differences in birth weight, fetal percentile, or PI.

The effect of DASH diet on pregnancy outcomes in gestational diabetes: a randomized controlled clinical trial

BACKGROUND/OBJECTIVES

The current study was performed to investigate the effects of the Dietary Approaches to Stop Hypertension (DASH) eating plan on pregnancy outcomes in pregnant women with gestational diabetes mellitus (GDM).

SUBJECTS/METHODS

This randomized controlled clinical trial was performed among 52 women diagnosed with GDM. Participants were randomly assigned to consume either the control (n=26) or the DASH diet (n=26) for 4 weeks. The control diet was designed to contain 45-55% carbohydrates, 15-20% protein and 25-30% total fat. The DASH diet was rich in fruits, vegetables, whole grains and low-fat dairy products, and contained lower amounts of saturated fats, cholesterol and refined grains with a total of 2400 mg/day sodium. The numbers of women who commenced insulin therapy after dietary intervention, the mode of delivery and prevalence of polyhydramnios were assessed. The length, weight and head circumference of infants were measured during the first 24 h after birth.

RESULTS

Whereas 46.2% of women in the DASH diet needed to have a cesarean section, this percentage for the control group was 80.8% (P=0.01). The percentage of those who needed to commence insulin therapy after intervention was also significantly different between the two groups (23% for DASH vs 73% for control group, P<0.0001). Infants born to mothers on the DASH diet had significantly lower weight (3222.7 vs 3818.8 g, P<0.0001), head circumference (34.2 vs 35.1 cm, P=0.01) and ponderal index (2.50 vs 2.87 kg/m(3), P<0.0001) compared with those born to mothers on the control diet.

CONCLUSIONS

In conclusion, consumption of DASH diet for 4 weeks among pregnant women with GDM resulted in improved pregnancy outcomes.

Enablers of and barriers to making healthy change during pregnancy in overweight and obese women

BACKGROUND

High Body Mass Index (BMI) during pregnancy is associated with an increased risk of adverse health outcomes. Making healthy change during pregnancy is beneficial, especially for overweight and obese women.

AIMS

The aim of this study was to explore the barriers and enablers identified by overweight and obese women that preclude and facilitate making healthy change during pregnancy.

METHOD

Twenty-six women who were overweight or obese during pregnancy were interviewed at 28 weeks gestational age. Interviews were transcribed verbatim and the analysis is based on the thematic analysis methodology.

RESULTS

The core concept of "being pregnant" indicated women consider this specific time as both a reason not to make healthy change as well as a motivation for change. Overweight and obese women cited the following barriers to making healthy change during pregnancy: physiological (e.g. pregnancy complications and tiredness); emotional (e.g. preference and mood); cognitive (e.g. lack knowledge); interpersonal (e.g. lack support); and environmental (e.g. availability of healthy choice). Similar enablers were identified by overweight and obese women: physiological (e.g. relief of pregnancy symptoms); emotional (e.g. approval and commitment); cognitive (e.g. knowledge and belief); interpersonal (e.g. family support); and environmental (e.g. help from others). More barriers than enablers were given, indicating that women were more sensitive to barriers than the enablers for making healthy change. Factors viewed by some women as barriers were viewed as enablers by others.

CONCLUSION

When designing interventions to promote healthy eating and physical activity during pregnancy, individually focused interventions must be implemented in conjunction with environmental-level interventions to facilitate behaviour change.

The influence of a low glycemic index dietary intervention on maternal dietary intake, glycemic index and gestational weight gain during pregnancy: a randomized controlled trial

BACKGROUND

Maternal diet is known to impact pregnancy outcome. Following a low glycemic index (GI) diet during pregnancy has been shown to improve maternal glycemia and reduce infant birthweight and may be associated with a higher fibre intake. We assessed the impact of a low GI dietary intervention on maternal GI, nutritional intake and gestational weight gain (GWG) during pregnancy. Compliance and acceptability of the low GI diet was also examined.

METHOD

Eight hundred women were randomised in early pregnancy to receive low GI and healthy eating dietary advice or to receive standard maternity care. The intervention group received dietary advice at a group education session before 22 weeks gestation. All women completed a 3 day food diary during each trimester of pregnancy. Two hundred and thirty five women from the intervention arm and 285 women from the control arm returned complete 3x3d FDs and were included in the present analysis.

RESULTS

Maternal GI was significantly reduced in the intervention group at trimester 2 and 3. The numbers of women within the lowest quartile of GI increased from 37% in trimester 1 to 52% in trimester 3 (P < 0.001) among the intervention group. The intervention group had significantly lower energy intake (P < 0.05), higher protein (% TE) (P < 0.01) and higher dietary fibre intake (P < 0.01) post intervention. Consumption of food groups with known high GI values were significantly reduced among the intervention group. Women in the intervention low GI group were less likely to exceed the Institute of Medicine's GWG goals.

CONCLUSION

A dietary intervention in early pregnancy had a positive influence on maternal GI, food and nutrient intakes and GWG. Following a low GI diet may be particularly beneficial for women at risk of exceeding the GWG goals for pregnancy.

Diet and carbohydrate food knowledge of multi-ethnic women: a comparative analysis of pregnant women with and without Gestational Diabetes Mellitus

Background

Diet therapy is the cornerstone for the management of gestational diabetes mellitus (GDM). Carbohydrate is the primary nutrient affecting postprandial blood glucose levels. Hence, knowledge of food containing carbohydrates can assist women with GDM optimize glycemic control. Despite that, there is a paucity of research on carbohydrate-related knowledge of women with GDM. The United Arab Emirates (UAE) has one of the highest prevalence of diabetes (19.2%) in the world. This study compared diet and knowledge of carbohydrate-containing foods among pregnant women with and without GDM in the UAE.

Methods

The sample consisted of multi-ethnic women with GDM (n = 94) and a control group of healthy pregnant women (n = 90) attending prenatal clinics in three hospitals in Al Ain, UAE. Data were collected using a questionnaire and a 24-hour recall. Knowledge of food sources of carbohydrate, dietary patterns, and nutrient intakes of the two groups were compared.

Results

There were no significant differences in the mean knowledge score of food sources of carbohydrate between women with GDM and that of pregnant women without GDM. Similarly, there were no significant differences in energy and nutrient intakes between the two groups with the exception of percent energy from protein. Women with GDM reported significantly lower intake of fruits and fruit juices (P = 0.012) and higher consumption of milk and yogurt (P = 0.004) compared to that of women without GDM. Twenty-two percent of women with GDM indicated they never visited a dietitian for counseling while 65% reported they visited a dietitian only once or twice during the pregnancy. Predictors of carbohydrate knowledge score were perceived knowledge of diet and GDM and parity among women with GDM and parity and educational level among those without GDM.

Conclusion

The results of the study highlight the urgent need to provide nutrition education for women with GDM in the UAE.

Effect of low glycemic load diet with and without wheat bran on glucose control in gestational diabetes mellitus: A randomized trial

BACKGROUND

A low-glycemic index diet is effective in blood glucose control of diabetic subjects, reduces insulin requirement in women with gestation diabetes mellitus (GDM) and improves pregnancy outcomes when used from beginning of the second trimester. However there are limited reports to examine the effect of low glycemic load (LGL) diet and fiber on blood glucose control and insulin requirement of women with GDM. Therefore, the aim of this study was to examine the effect of low glycemic load diet with and without fiber on reducing the number of women with GDM requiring insulin.

MATERIALS AND METHODS

All GDM women (n = 31) were randomly allocated to consume either a LGL diet with Fiber or LGL diet.

RESULTS

We found that 7 (38.9%) of 18 women with GDM in Fiber group and 10 (76.9%) in "Without Fiber" group required insulin treatment.

CONCLUSION

The LGL diet with added fiber for women with GDM dramatically reduced the number needing for insulin treatment.

Dietary glycemic index during pregnancy is associated with biomarkers of the metabolic syndrome in offspring at age 20 years

OBJECTIVE

Growing evidence indicates that metabolic syndrome is rooted in fetal life with a potential key role of nutrition during pregnancy. The objective of the study was to assess the possible associations between the dietary glycemic index (GI) and glycemic load (GL) during pregnancy and biomarkers of the metabolic syndrome in young adult offspring.

METHODS

Dietary GI and GL were assessed by questionnaires and interviews in gestation week 30 and offspring were clinically examined at the age of 20 years. Analyses based on 428 mother-offspring dyads were adjusted for maternal smoking during pregnancy, height, pre-pregnancy body mass index (BMI), education, energy intake, and the offspring's ambient level of physical activity. In addition, possible confounding by gestational diabetes mellitus was taken into account.

OUTCOME MEASURES

Waist circumference, blood pressure, HOMA insulin resistance (HOMA-IR) and plasma levels of fasting glucose, triglycerides, HDL cholesterol, LDL cholesterol, total cholesterol, insulin, and leptin were measured in the offspring.

RESULTS

Significant associations were found between dietary GI in pregnancy and HOMA-IR (the relative increase in HOMA-IR per 10 units' GI increase was 1.09 [95% CI: 1.01, 1.16], p = 0.02), insulin (1.09 [95% CI: 1.02, 1.16], p = 0.01) and leptin (1.21 [95% CI: 1.06, 1.38], p = 0.01) in the offspring; whereas no associations were detected for GL.

CONCLUSIONS

Our data suggests that high dietary GI in pregnancy may affect levels of markers for the metabolic syndrome in young adult offspring in a potentially harmful direction.

Is glycaemic index (GI) a valid measure of carbohydrate quality?

Recent criticisms of the glycaemic index (GI) focus on its validity with assertions that GI methodology is not valid, GI values are inaccurate and imprecise, GI does not predict what foods are healthy and that whole grain and fibre are better markers of carbohydrate quality than GI. None of the critics provide sound reasons for rejecting GI because some of their arguments are based on flagrant errors in understanding and interpretation while others are not supported by current data or are inconsistent with other nutritional recommendations. This paper addresses current criticisms of GI and outlines reasons why GI is valid: (1) GI methodology is accurate and precise enough for practical use; (2) GI is a property of foods; and (3) GI is biologically meaningful and relevant to virtually everyone. Current dietary guidelines recommend increased consumption of whole grains and dietary fibre but do not mention GI. However, this is illogical because the evidence that GI affects health outcomes is at least as good or better than that for whole grains and fibre. GI is a novel concept from a regulatory point of view and a number of problems need to be addressed to successfully translate GI knowledge into practice. The problems are not insurmountable but no progress can be made until bias and misunderstanding about GI can be overcome and there is better agreement about what is the actual state of knowledge on GI so that the real issues can be identified and addressed.

Carbohydrates, glycemic index, and pregnancy outcomes in gestational diabetes

This review critically evaluates the current evidence regarding the effect of the dietary glycemic index (GI) on pregnancy outcomes in gestational diabetes mellitus (GDM). Current evidence, although limited, consistently supports the advantages of, and has demonstrated no disadvantages of, a low-GI diet. We conclude that pregnant women with GDM are likely to benefit from following a low-GI meal pattern, with no significant side effects, and consideration of the GI should be given when formulating a diet for GDM. However, until larger scale intervention trials are completed, an exclusive low-GI diet should not replace the current recommended diets for GDM from relevant government and health agencies. Further studies that intervene at an earlier stage of pregnancy are required.

Antenatal interventions for reducing weight in obese women for improving pregnancy outcome

BACKGROUND

Being obese and pregnant is associated with substantial risks for the mother and her child. Current weight management guidance for obese pregnant women is limited. The latest recommendations suggest that obese pregnant women should gain between 5.0 and 9.1 kg during the pregnancy period, and weight loss is discouraged. However, observational studies indicate that some obese pregnant women, especially those who are heavier, lose weight during pregnancy. Furthermore, some obese pregnant women may intentionally lose weight. The safety of weight loss when pregnant and obese is not substantiated; some observational studies suggest that risks associated with weight loss such as pre-eclampsia are improved, but others indicate that the incidence of small- for-gestational infants are increased. It is important to evaluate interventions that are designed to reduce weight in obese pregnant women so that the safety of weight loss during this period can be established.

OBJECTIVES

To evaluate the effectiveness of interventions that reduce weight in obese pregnant women.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2012) and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials, 'quasi-random' studies and cluster-randomised trials comparing a weight-loss intervention with routine care or more than one weight loss intervention. Cross-over trials were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We identified no studies that met the inclusion criteria for this review.

MAIN RESULTS

There were no included trials.

AUTHORS' CONCLUSIONS

There are no trials designed to reduce weight in obese pregnant women. Until the safety of weight loss in obese pregnant women can be established, there can be no practice recommendations for these women to intentionally lose weight during the pregnancy period. Further study is required to explore the potential benefits, or harm, of weight loss in pregnancy when obese before weight loss interventions in pregnancy can be designed. Qualitative research is also required to explore dietary habits of obese pregnant women, especially those who are morbidly obese.

Effects of metformin-diet intervention before and throughout pregnancy on obstetric and neonatal outcomes in patients with polycystic ovary syndrome

OBJECTIVE

Prospectively assess whether metformin/diet pre-conception and throughout pregnancy would safely reduce first trimester miscarriage and improve pregnancy outcomes in women with polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

In 76 PCOS women, first pregnancy miscarriage and live birth were compared before and on metformin/diet, started 6.8 months (median) before conception, continued throughout pregnancy. On metformin 2-2.55 g/day, low glycemic index diet, first pregnancy outcomes in PCOS were compared with 156 community obstetric practice women (controls).

MAIN OUTCOME MEASURES

Live births, miscarriage, birth <37 weeks gestation, gestational diabetes, pre-eclampsia, fetal macrosomia.

RESULTS

In 76 PCOS women before metformin-diet, there were 36 miscarriages (47%) and 40 live births vs. 14 (18%) miscarriages and 62 live births on metformin-diet 6.8 months before conception and throughout pregnancy, p = 0.0004, OR 3.99, 95% CI 1.91-8.31. On metformin-diet, PCOS women did not differ (p > 0.08) from controls for birth <37 weeks gestation, gestational diabetes, pre-eclampsia, or fetal macrosomia.

CONCLUSIONS

Metformin-diet before and during pregnancy in PCOS reduces miscarriage and adverse pregnancy outcomes. Study limitation: individual benefits of the diet alone and diet plus metformin could not be assessed separately. Randomized, controlled clinical trials now need to be done with a larger number of patients.

Low Glycemic Index Carbohydrates versus All Types of Carbohydrates for Treating Diabetes in Pregnancy: A Randomized Clinical Trial to Evaluate the Effect of Glycemic Control

Background. Due to the higher prevalence of obesity and diabetes mellitus (DM), more pregnant women complicated with diabetes are in need of clinical care. Purpose. Compare the effect of including only low glycemic index (GI) carbohydrates (CHO) against all types of CHO on maternal glycemic control and on the maternal and newborn's nutritional status of women with type 2 DM and gestational diabetes mellitus (GDM). Methods. Women (n = 107, ≤29 weeks of gestation) were randomly assigned to one of two nutrition intervention groups: moderate energy and CHO restriction (Group 1: all types of CHO, Group 2: low GI foods). Results. No baseline differences in clinical data were observed. Capillary glucose concentrations throughout pregnancy were similar between groups. Fewer women in Group 2 exceeded weight gain recommendations. Higher risk of prematurity was observed in women in Group 2. No differences in glycemic control were observed between women with type 2 DM and those with GDM. Conclusions. Inclusion of low GI CHO as part of a comprehensive nutrition intervention is equally effective in improving glycemic control as compared to all types of CHO. This strategy had a positive effect in preventing excessive maternal weight gain but increased the risk of prematurity.

Does a low glycaemic index (GI) diet cost more during pregnancy?

&#160;The aim of this study was to examine the monetary cost of dietary change among pregnant women before and after receiving low glycaemic index (GI) dietary advice. The pregnant women in this study were a subgroup of participants in the Pregnancy and Glycaemic Index Outcomes (PREGGIO) study. Twenty women from the low GI dietary advice group, who had completed their pregnancies, were randomly chosen. All these women had completed three day food records at 12&#8211;16 weeks and again around 36 weeks of gestation. Consumer food prices were applied to recorded dietary intake data. The mean &#177; SD GI of the diet reduced from 55.1 &#177; 4.3 to 51.6 &#177; 3.9 (p = 0.003). The daily cost of the diet (AUD) was 9.1 &#177; 2.7 at enrolment and 9.5 &#177; 2.1 prior to delivery was not significantly different (p = 0.52). There were also no significant differences in the daily energy intake (p = 0.2) or the daily cost per MJ (p = 0.16). Women were able to follow low GI dietary advice during pregnancy with no significant increase in the daily costs.

The obstetric dilemma: an ancient game of Russian roulette, or a variable dilemma sensitive to ecology?

The difficult birth process of humans, often described as the "obstetric dilemma," is commonly assumed to reflect antagonistic selective pressures favoring neonatal encephalization and maternal bipedal locomotion. However, cephalo-pelvic disproportion is not exclusive to humans, and is present in some primate species of smaller body size. The fossil record indicates mosaic evolution of the obstetric dilemma, involving a number of different evolutionary processes, and it appears to have shifted in magnitude between Australopithecus, Pleistocene Homo, and recent human populations. Most attention to date has focused on its generic nature, rather than on its variability between populations. We re-evaluate the nature of the human obstetric dilemma using updated hominin and primate literature, and then consider the contribution of phenotypic plasticity to variability in its magnitude. Both maternal pelvic dimensions and fetal growth patterns are sensitive to ecological factors such as diet and the thermal environment. Neonatal head girth has low plasticity, whereas neonatal mass and maternal stature have higher plasticity. Secular trends in body size may therefore exacerbate or decrease the obstetric dilemma. The emergence of agriculture may have exacerbated the dilemma, by decreasing maternal stature and increasing neonatal growth and adiposity due to dietary shifts. Paleodemographic comparisons between foragers and agriculturalists suggest that foragers have considerably lower rates of perinatal mortality. In contemporary populations, maternal stature remains strongly associated with perinatal mortality in many populations. Long-term improvements in nutrition across future generations may relieve the dilemma, but in the meantime, variability in its magnitude is likely to persist.

Possible relation between maternal consumption of added sugar and sugar-sweetened beverages and birth weight--time trends in a population

Background

High birth weight (BW) is a risk factor for later obesity. In Norway, mean BW and proportion of large newborns increased from 1989 to 2000 and subsequently decreased to the 1989 level by 2010. The purpose of the study was to explore causes of this temporary increase.

Methods

From a regional prospective database pregnancy and newborn data were extracted for all 33088 singleton pregnancies resulting in live infants born at term without malformations during 1989–2010. Trends in BW, ponderal index and proportion of large newborns were related to individual prenatal exposures, including pre-pregnancy body mass index (PP-BMI) and gestational weight gain (GWG) for the years 2001–2010, and thereafter related ecologically to national population data on consumption of nutrients and physical activity.

Results

For the regional cohort mean (standard deviation) BW increased from 3580 (453) grams in 1989/90 to 3633 (493) grams in 2001/02 (p<0.001), and decreased to 3583 (481) grams in 2009/10 (p<0.001). The proportion with BW>4500 grams increased from 2.6% to 4.8% (p<0.001) and subsequently decreased to 3.3% (p=0.002). The trends remained after adjustment for relevant exposures. For the years 2001/02 to 2009/10 (n= 15240) mean (SD) PP-BMI increased from 24.36 (4.44) to 24.85 (5.02) kg/m² (p<0.001) while GWG decreased from 14.79 (5.85) to 13.86 (5.79) kg (p<0.001). The estimated net effect of changes in PP-BMI, GWG and other known exposures was a 6 grams reduction in BW from 2001/02 to 2009/10, leaving 44 grams reduction unexplained. National consumption of major nutrients did not change, but consumption of sucrose, in large part as sugar-sweetened beverages (SSB) changed in parallel to the BW trends.

Conclusion

The temporary increase in BW and large babies in the regional cohort was identical to that reported for Norway. Individual level data on known pregnancy related predictors for BW could not explain these changes, but the parallel time trend in national consumption of sucrose, in particular as SSB, may lend support to a hypothesis that intake of sugar may have a direct effect on BW and infant body proportions independent of effects through PP-BMI and GWG.

Antenatal dietary advice and supplementation to increase energy and protein intake

BACKGROUND

Gestational weight gain is positively associated with fetal growth, and observational studies of food supplementation in pregnancy have reported increases in gestational weight gain and fetal growth.

OBJECTIVES

To assess the effects of advice during pregnancy to increase energy and protein intake, or of actual energy and protein supplementation, on energy and protein intakes, and the effect on maternal and infant health outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (22 July 2011) and contacted researchers in the field. We updated the search on 12 July 2012 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

Randomised controlled trials of dietary advice to increase energy and protein intake, or of actual energy and protein supplementation, during pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and assessed risk of bias. Two review authors independently extracted data and checked for accuracy. Extracted data were supplemented by additional information from the trialists we contacted.

MAIN RESULTS

We examined 110 reports corresponding to 46 trials. Of these trials, 15 were included, 30 were excluded, and one is ongoing. Overall, 15 trials involving 7410 women were included.Nutritional advice (four trials, 790 women)Women given nutritional advice had a lower relative risk of having a preterm birth (two trials, 449 women) (risk ratio (RR) 0.46, 95% CI 0.21 to 0.98 ), head circumference at birth was increased in one trial (389 women) (mean difference (MD) 0.99 cm, 95% CI 0.43 to 1.55) and protein intake increased (three trials, 632 women) (protein intake: MD +6.99 g/day, 95% CI 3.02 to 10.97). No significant differences were observed on any other outcomes.Balanced energy and protein supplementation (11 trials, 5385 women)Risk of stillbirth was significantly reduced for women given balanced energy and protein supplementation (RR 0.62, 95% CI 0.40 to 0.98, five trials, 3408 women), mean birthweight was significantly increased (random-effects MD +40.96 g, 95% CI 4.66 to 77.26 , Tau(2)= 1744, I(2) = 44%, 11 trials, 5385 women). There was also a significant reduction in the risk of small-for-gestational age (RR 0.79, 95% CI 0.69 to 0.90, I(2) = 16%, seven trials, 4408 women). No significant effect was detected for preterm birth or neonatal death.High-protein supplementation (one trial, 1051 women)High-protein supplementation (one trial, 505 women), was associated with a significantly increased risk of small-for-gestational age babies (RR 1.58, 95% CI 1.03 to 2.41).Isocaloric protein supplementation (two trials, 184 women)Isocaloric protein supplementation (two trials,184 women) had no significant effect on birthweight and weekly gestational weight gain.

AUTHORS' CONCLUSIONS

This review provides encouraging evidence that antenatal nutritional advice with the aim of increasing energy and protein intake in the general obstetric population appears to be effective in reducing the risk of preterm birth, increasing head circumference at birth and increasing protein intake, there was no evidence of benefit or adverse effect for any other outcome reported.Balanced energy and protein supplementation seems to improve fetal growth, and may reduce the risk of stillbirth and infants born small-for-gestational age. High-protein supplementation does not seem to be beneficial and may be harmful to the fetus. Balanced-protein supplementation alone had no significant effects on perinatal outcomes.The results of this review should be interpreted with caution, the risk of bias was either unclear or high for at least one category examined in several of the included trials and the quality of the evidence was low for several important outcomes. Also the anthropometric characteristics of the general obstetric population is changing, therefore, those developing interventions aimed at altering energy and protein intake should ensure that only those women likely to benefit are included. Large, well designed randomised trials are needed to assess the effects of increasing energy and protein intake during pregnancy in women whose intake is below recommended levels.

Low glycaemic index diet in pregnancy to prevent macrosomia (ROLO study): randomised control trial

OBJECTIVE

To determine if a low glycaemic index diet in pregnancy could reduce the incidence of macrosomia in an at risk group.

DESIGN

Randomised controlled trial.

SETTING

Maternity hospital in Dublin, Ireland.

PARTICIPANTS

800 women without diabetes, all in their second pregnancy between January 2007 to January 2011, having previously delivered an infant weighing greater than 4 kg.

INTERVENTION

Women were randomised to receive no dietary intervention or start on a low glycaemic index diet from early pregnancy.

MAIN OUTCOMES

The primary outcome measure was difference in birth weight. The secondary outcome measure was difference in gestational weight gain.

RESULTS

No significant difference was seen between the two groups in absolute birth weight, birthweight centile, or ponderal index. Significantly less gestational weight gain occurred in women in the intervention arm (12.2 v 13.7 kg; mean difference -1.3, 95% confidence interval -2.4 to -0.2; P=0.01). The rate of glucose intolerance was also lower in the intervention arm: 21% (67/320) compared with 28% (100/352) of controls had a fasting glucose of 5.1 mmol/L or greater or a 1 hour glucose challenge test result of greater than 7.8 mmol/L (P=0.02).

CONCLUSION

A low glycaemic index diet in pregnancy did not reduce the incidence of large for gestational age infants in a group at risk of fetal macrosomia. It did, however, have a significant positive effect on gestational weight gain and maternal glucose intolerance.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN54392969.

Maternal dietary glycaemic load during pregnancy and gestational weight gain, birth weight and postpartum weight retention: a study within the Danish National Birth Cohort

Dietary glycaemic index and glycaemic load (GL) have been related to obesity and other health outcomes. The objective of the present study was to examine the associations between maternal dietary GL and gestational weight gain, birth weight, the risk of giving birth to a child large-for-gestational age (LGA) or small-for-gestational age and postpartum weight retention (PPWR). Data were derived from the Danish National Birth Cohort (1996-2002), including data on gestational and lifestyle factors in pregnancy and 18 months postpartum. Dietary data were collected using a validated FFQ. Information on birth outcome was obtained through registers. A total of 47,003 women were included. The associations between the GL and birth outcome, gestational weight gain, assessed between weeks 12 and 30 of gestation, and PPWR were analysed by linear and logistic regression. Birth weight increased by 36 g from the lowest to highest GL quintile (95% CI 19, 53 g), and an increased risk of LGA of 14% was detected in the highest GL quintile compared with the lowest GL quintile. Among normal-weight and overweight women, higher gestational weight gain rates were detected in the highest GL quintile (26 g/week (95% CI 19, 34) and 30 g/week (95% CI 13, 46), respectively). The association between the GL and PPWR was most pronounced among pre-pregnant obese women, with an increase in weight retention of 1·3 (95% CI 0·2, 2·8) kg from the lowest to highest GL quintile. The GL may play a role for excessive gestational weight gain and PPWR, which may be more pronounced among overweight and obese women.

Treatment with constitutive androstane receptor ligand during pregnancy prevents insulin resistance in offspring from high-fat diet-induced obese pregnant mice

The constitutive androstane receptor (CAR) has been reported to decrease insulin resistance even during pregnancy, while exposure to a high-fat diet (HFD) in utero in mice can induce a type 2 diabetes phenotype that can be transmitted to the progeny. Therefore, we examined whether treatment with a CAR ligand during pregnancy could prevent hypertension, insulin resistance, and hyperlipidemia in the offspring from HFD-induced obese pregnant mice (OH mice). We employed four groups of offspring from HFD-fed and control diet-fed pregnant mice with or without treatment with a CAR ligand. Treatment with a CAR ligand during pregnancy improved glucose tolerance and the levels of triglyceride and adipocytokine and restored the changes induced by HFD with amelioration of hypertension in the adult OH mice. This treatment also increased adiponectin mRNA expression, suppressed leptin expression in adipose tissues of OH mice, and abolished the effect of HFD on the epigenetic modifications of the genes encoding adiponectin and leptin in the offspring during immaturity and adulthood. Our data suggest that CAR might be a potential therapeutic target to prevent metabolic syndrome in adulthood of offspring exposed to an HFD in utero.

Effects of a high-fat diet exposure in utero on the metabolic syndrome-like phenomenon in mouse offspring through epigenetic changes in adipocytokine gene expression

The links between obesity in parents and their offspring and the role of genes and a shared environment are not completely understood. Adipocytokines such as leptin and adiponectin play important roles in glucose and lipid metabolism. Therefore, we examined whether the offspring from dams exposed to a high-fat diet during pregnancy (OH mice) exhibited hypertension, insulin resistance, and hyperlipidemia along with epigenetic changes in the expression of adipocytokine genes. OH mice were significantly heavier than the offspring of dams exposed to a control diet during pregnancy (OC mice) from 14 wk of age after an increased caloric intake from 8 wk. OH mice exhibited higher blood pressure and worse glucose tolerance than the OC mice at 24 wk. Total triglyceride and leptin levels were significantly higher and the adiponectin level was significantly lower in OH compared with OC mice at 12 wk of age. This was associated with changes in leptin and adiponectin expression in white adipose tissue. There were lower acetylation and higher methylation levels of histone H3 at lysine 9 of the promoter of adiponectin in adipose tissues of OH mice at 2 wk of age as well as at 12 and 24 wk of age compared with OC mice. In contrast, methylation of histone 4 at lysine 20 in the leptin promoter was significantly higher in OH compared with OC mice. Thus, exposure to a high-fat diet in utero might cause a metabolic syndrome-like phenomenon through epigenetic modifications of adipocytokine, adiponectin, and leptin gene expression.

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.

Gestational Diabetes

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy and is strongly related to subsequent risk of type 2 diabetes. The epidemics of obesity and diabetes and the increasing incidence of GDM in recent years highlight the importance of preventing GDM among women at high risk to avoid the associated short- and long-term adverse health outcomes for both mothers and their offspring. Indeed, women may be more likely to adopt healthy lifestyle habits during pregnancy and maintain these habits into the postpartum period. Although there is substantial evidence that targeting at-risk groups for type 2 diabetes prevention is effective if lifestyle changes are made, relatively little attention has been paid to the prevention of GDM. Therefore, the objective of this article is to review the scientific evidence regarding the association between modifiable risk factors and GDM; discuss how lifestyle interventions, including weight management through diet and exercise could be successful in reducing the risk for GDM; and provide recommendations for future lifestyle intervention programs with a focus on translation and dissemination of research findings.

The carnivore connection hypothesis: revisited

The "Carnivore Connection" hypothesizes that, during human evolution, a scarcity of dietary carbohydrate in diets with low plant : animal subsistence ratios led to insulin resistance providing a survival and reproductive advantage with selection of genes for insulin resistance. The selection pressure was relaxed at the beginning of the Agricultural Revolution when large quantities of cereals first entered human diets. The "Carnivore Connection" explains the high prevalence of intrinsic insulin resistance and type 2 diabetes in populations that transition rapidly from traditional diets with a low-glycemic load, to high-carbohydrate, high-glycemic index diets that characterize modern diets. Selection pressure has been relaxed longest in European populations, explaining a lower prevalence of insulin resistance and type 2 diabetes, despite recent exposure to famine and food scarcity. Increasing obesity and habitual consumption of high-glycemic-load diets worsens insulin resistance and increases the risk of type 2 diabetes in all populations.

Association between maternal and fetal weight gain: cohort study

CONTEXT AND OBJECTIVE

Excessive gestational weight gain is related to many complications (both maternal and fetal), such as macrosomia. The most common complications in macrosomic fetuses include: increased risk of intrauterine death, need for intensive care, fractures, neonatal hyperbilirubinemia, paralysis of the brachial plexus and obesity in childhood and adulthood. The aim of this study was to evaluate the association between gestational and fetal weight gain and the incidence of macrosomia in two maternity hospitals.

DESIGN AND SETTING

Cohort study in two public maternity hospitals in Goiânia, Brazil.

METHODS

This was a cohort study on 200 healthy pregnant women with normal body mass index, divided into two groups: one with normal weight gain and the other with excessive weight gain during pregnancy.

RESULTS

The cohorts were similar regarding maternal age, per capita income, schooling level and reproductive behavior. The fetal weight was greater in the cohort with excessive maternal weight gain (3,388.83 g ± 514.44 g) than in the cohort with normal weight (3,175.86 g ± 413.70 g) (P < 0.01). The general incidence of macrosomia was 6.5%: 13.0% (13 cases) in the cohort with excessive maternal weight gain and 0.0% (0 cases) in the cohort with adequate weight gain.

CONCLUSION

Excessive maternal weight gain was associated with increased fetal birth weight and incidence of macrosomia.

Impact of maternal physical activity and infant feeding practices on infant weight gain and adiposity

Increasing evidence supports the contribution of intrauterine environmental exposures on obesity risk in offspring. Few studies have included maternal and infant lifestyle factors. Our objective was to study the impact of maternal physical activity, infant feeding, and screen time on offspring weight gain and adiposity. In a prospective cohort study, 246 mothers underwent testing during pregnancy to assess glucose tolerance status and insulin sensitivity. Anthropometry and questionnaires on physical activity, infant feeding, and screen time were completed. Multiple-linear regression was performed to examine the impact of maternal and infant factors on infant weight gain and weight-for-length z-score at 1 year. Infant weight outcomes were negatively predicted by maternal pregravid vigorous/sport index and exclusive breastfeeding duration. After adjustment, each unit increase in maternal pregravid vigorous/sport index decreased infant weight gain by 218.6 g (t = 2.44, P = 0.016) and weight-for-length z-score by 0.20 (t = 2.17, P = 0.031). Each month of exclusive breastfeeding reduced infant weight gain by 116.4 g (t = 3.97, P < 0.001) and weight-for-length z-score by 0.08 (t = 2.59, P = 0.01). Maternal pregravid physical activity and exclusive breastfeeding duration are associated with weight gain and adiposity as early as 1 year of age.

Intergenerational cycle of obesity and diabetes: how can we reduce the burdens of these conditions on the health of future generations?

Prepregnancy overweight or obesity and excessive gestational weight gain have been associated with increased risk of maternal and neonatal complications. Moreover, offspring from obese women are more likely to develop obesity, diabetes mellitus, and cardiovascular diseases in their lifetime. Gestational diabetes mellitus (GDM) is one of the most common complications associated with obesity and appears to have a direct impact on the future metabolic health of the child. Fetal programming of metabolic function induced by obesity and GDM may have intergenerational effect and thus perpetuate the epidemic of cardiometabolic conditions. The present paper thus aims at discussing the impact of maternal obesity and GDM on the developmental programming of obesity and metabolic disorders in the offspring. The main interventions designed to reduce maternal obesity and GDM and their ability to break the vicious circle that perpetuates the transmission of obesity and metabolic conditions to the next generations are also addressed.

Interventions for preventing gestational diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

The prevalence of gestational diabetes mellitus (GDM) is increasing worldwide. GDM is associated with increased risks for mother and child during pregnancy and in later life. The aim of this article is to systematically review literature on the effectiveness of interventions to prevent GDM.

METHODS

Controlled trials found in PubMed, EMBASE, or CENTRAL were selected. The primary outcome was GDM, and relevant secondary outcomes were maternal fasting blood glucose and large-for-gestational age (LGA) or macrosomia. Data were combined in meta-analyses, and the quality of evidence for the effectiveness of the interventions was assessed in a GRADE approach.

RESULTS

Nineteen studies evaluating six types of interventions were included. Dietary counseling significantly reduced GDM incidence compared to standard care. None of the interventions was effective in lowering maternal fasting blood glucose. Low glycemic index (LGI) diet advice and an exercise program significantly reduced the risk of macrosomia. The quality of evidence for these outcomes was low.

CONCLUSIONS

The results indicate that there may be some benefits of dietary counseling, an LGI diet advice, or an exercise program. However, better-designed studies are required to generate higher quality evidence. At the moment, no strong conclusions can be drawn with regard to the best intervention for prevention of GDM.