Prediction of pre-diabetes and type 2 diabetes nine years postpartum using serum metabolome in pregnant women with gestational diabetes requiring pharmacological treatment.

AIMS: We examined the association between serum metabolome in women with pharmacologically treated gestational diabetes (GDM) and measures of glucose metabolism 9 years postpartum. METHODS: Serum targeted metabolome, adiponectin, inflammatory markers, and insulin-like growth factor-binding protein-1 phosphoisoforms were analyzed at the time of diagnosing GDM. Glucose metabolism and insulin resistance were assessed at 9 years postpartum. Data from 119 subjects were available for analyses. Associations between baseline measures and future measures of glycemia were examined with univariate regressions and multivariate prediction models. This is a secondary analysis of a previous prospective trial (NCT02417090). RESULTS: Baseline serum markers were most strongly related to measures of insulin resistance at 9-years follow-up. In multivariate analyses combination of IDL cholesterol, early gestational weight gain and in oral glucose tolerance test fasting and 2-h glucose predicted development of disorders of glucose metabolism (pre-diabetes and/or type 2 diabetes) better than clinical predictors alone (ROC-AUC 0.75 vs. 0.65, p = 0.020). CONCLUSIONS: Serum metabolome in pregnancy in women with GDM is related to future glucose metabolism and insulin resistance. Compared to clinical variables alone metabolome might result in better prediction of future disorders of glucose metabolism and could facilitate personalized risk stratification for postpartum interventions and follow-up.

Potential pathobionts in vaginal microbiota are affected by fish oil and/or probiotics intervention in overweight and obese pregnant women.

New means to stabilize the microbial balance during pregnancy could benefit maternal health. Our objectives were to investigate in overweight/obese pregnant women 1) the impact of long-chain polyunsaturated fatty acids (fish oil) and/or probiotics on the vaginal microbiota, 2) its relation to gestational diabetes mellitus (GDM) and 3) its interaction with vaginal active matrix metalloproteinase-8 (aMMP-8) and serum high sensitivity C-reactive protein (hsCRP) and phosphorylated insulin-like growth factor-binding protein-1 (phIGFBP-1), IGFBP-1 and aMMP-8. The women were allocated to fish oil + placebo, probiotics + placebo, fish oil + probiotics and placebo + placebo-groups, from early pregnancy onwards (fish oil: 1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid; probiotics: Lacticaseibacillus rhamnosus HN001 (formerly Lactobacillus rhamnosus HN001) and Bifidobacterium animalis ssp. lactis 420, 1010 colony-forming units each). Vaginal and serum samples (early pregnancy, n = 112; late pregnancy, n = 116), were analyzed for vaginal microbiota using 16S rRNA gene amplicon sequencing and vaginal aMMP-8 and serum hsCRP, aMMP-8, phIGFBP-1 and IGFBP-1 by immunoassays. GDM was diagnosed from a 2-h 75 g OGTT. ClinicalTrials.gov, NCT01922791. The intervention exerted effects on many low-abundant bacteria. Compared to the placebo-group, there was a lower abundance of potential pathobionts, namely Ureaplasma urealyticum in the fish oil-group, Ureaplasma, U. urealyticum and Prevotella disiens in the probiotics-group, Dialister invisus and Prevotella timonensis in the fish oil + probiotics-group. Moreover, probiotics decreased the abundance of a few potential pathobionts during pregnancy. Many bacteria were related to GDM. The vaginal aMMP-8 level correlated significantly with α-diversity and inversely with two Lactobacillus species. Dietary interventions, especially probiotics, may have beneficial effects on the vaginal microbiota during pregnancy.

A healthy dietary pattern with a low inflammatory potential reduces the risk of gestational diabetes mellitus.

PURPOSE: An optimal diet for lowering the risk of gestational diabetes mellitus (GDM) is still to be defined, but may comprise of nutrient intakes, dietary patterns, diet quality, and eating frequency. This study was designed to investigate the contribution of diet in developing GDM in a comprehensive way. METHODS: The dietary intake of overweight or obese women, a risk group for GDM (n = 351), was assessed using 3-day food diaries and diet quality questionnaires in early pregnancy. Eating frequency and nutrient intakes were calculated, and dietary patterns identified using principal component analysis. The inflammatory potential of the diet was determined by calculating the dietary inflammatory index (DII®) and energy-adjusted DII (E-DII™). GDM was diagnosed with an oral glucose tolerance test at 24-28 gestational weeks. RESULTS: Higher adherence to 'healthier dietary pattern' characterized by consumptions of vegetables and rye bread associated with a reduced risk of GDM (adjusted OR 0.27, 95% CI 0.11-0.70). Higher E-DII score, indicating pro-inflammatory diet, was associated with a 27% higher risk of GDM (adjusted OR 1.27; 95% CI 1.08-1.49) for each E-DII point. In the evaluation of nutrient intakes, total fat, saturated fatty acids (SFAs), and trans fatty acids were higher and fiber lower in women developing GDM compared to women not developing GDM (all p < 0.05). Intakes of total fat, SFAs, and trans fatty acids were also significant predictors for GDM (all p < 0.05). CONCLUSIONS: The results emphasize the importance of an overall healthy diet and limitation of foods with SFAs, and other nutrients with a high inflammatory potential in reducing the risk of GDM. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01922791, August 14, 2013.

Cord serum metabolome and birth weight in patients with gestational diabetes treated with metformin, insulin, or diet alone.

INTRODUCTION: Recent research has demonstrated the benefits of metformin treatment in gestational diabetes (GDM) on short-term pregnancy outcomes (including excessive fetal growth and pre-eclampsia), but its effects on fetal metabolism remain mostly unknown. Our aim was to study the effects of metformin treatment compared with insulin or diet on the cord serum metabolome and also to assess how these metabolites are related to birth weight (BW) in pregnancies complicated by GDM. RESEARCH DESIGN AND METHODS: Cord serum samples were available from 113, 97, and 98 patients with GDM treated with diet, insulin, and metformin, respectively. A targeted metabolome was measured using nuclear magnetic resonance spectroscopy. The patients in the metformin and insulin groups had participated in a previous randomized trial (NCT01240785). RESULTS: Cord serum alanine was elevated in the metformin group (0.53 mmol/L) compared with the insulin (0.45 mmol/L, p<0.001) and the diet groups (0.46 mmol/L, p<0.0001). All other measured metabolites were similar between the groups. The triglyceride (TG)-to-phosphoglyceride ratio, average very low-density lipoprotein particle diameter, docosahexaenoic acid, omega-3 fatty acids (FAs), and ratios of omega-3 and monounsaturated FA to total FA were inversely related to BW. The omega-6-to-total-FA and omega-6-to-omega-3-FA ratios were positively related to BW. Cholesterol in very large and large high-density lipoprotein (HDL) was positively (p<0.01) associated with BW when adjusted for maternal prepregnancy body mass index, gestational weight gain, glycated hemoglobin, and mode of delivery. CONCLUSIONS: Metformin treatment in GDM leads to an increase in cord serum alanine. The possible long-term implications of elevated neonatal alanine in this context need to be evaluated in future studies. Although previous studies have shown that metformin increased maternal TG levels, the cord serum TG levels were not affected. Cord serum HDL cholesterol and several FA variables are related to the regulation of fetal growth in GDM. Moreover, these associations seem to be independent of maternal confounding factors. TRIAL REGISTRATION NUMBER: NCT01240785.

Weight gain and body composition during pregnancy: a randomised pilot trial with probiotics and/or fish oil.

We evaluated the effects of fish oil and/or probiotic supplementation in a randomised placebo-controlled intervention pilot trial on gestational weight gain (GWG) and body composition. Additionally, the influence of gestational diabetes (GDM) on GWG and body composition was assessed. We randomised 439 overweight women into intervention groups: fish oil + placebo, probiotics + placebo, fish oil + probiotics and placebo + placebo (fish oil: 1·9 g DHA and 0·22 g EPA and probiotics: Lactobacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 1010 colony-forming units each). GDM was diagnosed with oral glucose tolerance test. Body composition was measured with air displacement plethysmography at randomisation (mean 13·9) and in late pregnancy (mean 35·2 gestational weeks). Intervention did not influence mean GWG or change in body fat mass/percentage (P > 0·17). Body composition in early pregnancy did not differ between the women who did or did not develop GDM (adjusted P > 0·23). Compared with the normoglycaemic women (n 278), women diagnosed with GDM (n 119) gained less weight (7·7 (sd 0·4) v. 9·3 (sd 0·4) kg, adjusted mean difference -1·66 (95 % CI -2·52, -0·80) and fat mass (0·4 (sd 0·4) v. 1·8 (sd 0·3) kg, adjusted mean difference -1·43 (95 % CI -2·19, -0·67) during the follow-up. In conclusion, adiposity of pregnant overweight women was not affected by supplementation with fish oil and/or probiotics, nor did it predict the development of GDM. However, adiposity was reduced in women with GDM compared with normoglycaemic women irrespective of the dietary intervention.

Metagenomics analysis of gut microbiota in response to diet intervention and gestational diabetes in overweight and obese women: a randomised, double-blind, placebo-controlled clinical trial.

OBJECTIVE: Gut microbiota and diet are known to contribute to human metabolism. We investigated whether the metagenomic gut microbiota composition and function changes over pregnancy are related to gestational diabetes mellitus (GDM) and can be modified by dietary supplements, fish oil and/or probiotics. DESIGN: The gut microbiota of 270 overweight/obese women participating in a mother-infant clinical study were analysed with metagenomics approach in early (mean gestational weeks 13.9) and late (gestational weeks 35.2) pregnancy. GDM was diagnosed with a 2 hour 75 g oral glucose tolerance test. RESULTS: Unlike women with GDM, women without GDM manifested changes in relative abundance of bacterial species over the pregnancy, particularly those receiving the fish oil + probiotics combination. The specific bacterial species or function did not predict the onset of GDM nor did it differ according to GDM status, except for the higher abundance of Ruminococcus obeum in late pregnancy in the combination group in women with GDM compared with women without GDM. In the combination group, weak decreases over the pregnancy were observed in basic bacterial housekeeping functions. CONCLUSIONS: The specific gut microbiota species do not contribute to GDM in overweight/obese women. Nevertheless, the GDM status may disturb maternal gut microbiota flexibility and thus limit the capacity of women with GDM to respond to diet, as evidenced by alterations in gut microbiota observed only in women without GDM. These findings may be important when considering the metabolic complications during pregnancy, but further studies with larger populations are called for to verify the findings.

The Impacts of Fish Oil and/or Probiotic Intervention on Low-Grade Inflammation, IGFBP-1 and MMP-8 in Pregnancy: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial.

BACKGROUND: We investigated the impact of fish oil and/or probiotics on serum and vaginal inflammatory and metabolic proteins and their relation to the onset of gestational diabetes mellitus (GDM). METHODS: Overweight/obese pregnant women received fish oil + placebo, probiotics + placebo, fish oil + probiotics or placebo + placebo from early pregnancy until six months postpartum (fish oil: 1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid; probiotics: Lactobacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 1010 colony-forming units each). Serum high sensitivity C-reactive protein (hsCRP) and serum/vaginal (s/v) phosphorylated insulin-like growth factor binding-protein-1 (phIGFBP-1), IGFBP-1 and matrix metalloproteinase 8 (MMP-8) were analyzed. GDM was diagnosed according to 2 h 75 g OGTT. RESULTS: The intervention had no impact on the change in proteins during pregnancy. Nevertheless, s-MMP-8 decreased and s-IGFBP-1 increased more in obese than in overweight women in the fish oil + probiotics group, while a decrease in s-MMP-8 was seen in obese women and an increase was seen in overweight women in the probiotics + placebo group. The late pregnancy s-phIGFBP-1 was higher in women who developed GDM in fish oil + probiotics-group compared to fish oil + placebo-group. The concentrations of s-phIGFBP-1 (635.9 ± 315.3 ng/mL vs. 753.2 ± 335.1 ng/mL, p = 0.005) and s-IGFBP-1 (3.78 ± 0.72 ng/mL vs. 3.96 ± 0.69 ng/mL, p = 0.042) were lower in early pregnancy in women who developed GDM than in women remaining healthy. CONCLUSIONS: The intervention per se had no impact on the proteins, but obesity and GDM may modify the effect. IGFBPs may affect the development of GDM.

Distinct Metabolic Profile in Early Pregnancy of Overweight and Obese Women Developing Gestational Diabetes.

BACKGROUND: Reliable biomarkers for gestational diabetes mellitus (GDM) would be beneficial in the early prevention of adverse metabolic outcomes during pregnancy and beyond. OBJECTIVES: The objective of this study was to investigate whether the early pregnancy serum metabolic profile differs in women developing GDM from those remaining healthy. Furthermore, we evaluated the potential of these metabolites to act as predictive markers for GDM. METHODS: This was a prospective study investigating overweight and obese [prepregnancy BMI (in kg/m2) ≥25 and >30, respectively] pregnant women (prepregnancy median BMI: 28.5; IQR: 26.4-31.5; n = 357). Fasting serum samples were analyzed with a targeted NMR approach in early pregnancy (median: 14.3 weeks of gestation). GDM was diagnosed on the basis of a 2-h, 75-g oral-glucose-tolerance test at a median of 25.7 weeks of gestation. RESULTS: In early pregnancy, 78 lipid metabolites differed in women who later developed GDM (n = 82) compared with those who remained healthy (n = 275) (ANCOVA, adjusted for confounding factors and corrected for multiple comparisons; false discovery rate <0.05). Higher concentrations of several-sized VLDL particles and medium- and small-sized HDL particles, and lower concentrations of very large-sized HDL particles, were detected in women developing GDM. Furthermore, concentrations of amino acids including 2 branched-chain amino acids, isoleucine and leucine, and GlycA, a marker for low-grade inflammation, were higher in women who developed GDM. Receiver operating characteristic analysis revealed that the most predictive marker for GDM was a higher concentration of small-sized HDL particles (AUC: 0.71; 95% CI: 0.67, 0.77; P < 0.001). CONCLUSIONS: We identified a distinct early pregnancy metabolomic profile especially attributable to small HDL particles in women developing GDM. The aberrant metabolic profile could represent a novel way to allow early identification of this most common medical condition affecting pregnant women. This trial was registered at clinicaltrials.gov as NCT01922791.

Efficacy of Fish Oil and/or Probiotic Intervention on the Incidence of Gestational Diabetes Mellitus in an At-Risk Group of Overweight and Obese Women: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial.

OBJECTIVE: To assess whether the risk of gestational diabetes mellitus (GDM) may be lowered and glucose metabolism improved by daily administration of fish oil and/or probiotic supplements in overweight and obese pregnant women. RESEARCH DESIGN AND METHODS: We randomized in a double-blind manner 439 women (mean 13.9 ± 2.1 gestational weeks [gw]) into four intervention groups: fish oil + placebo, probiotics + placebo, fish oil + probiotics, and placebo + placebo. Fish oil (1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid) and probiotic supplements (Lactobacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 1010 colony-forming units each) were provided for daily consumption from randomization beyond delivery. Primary outcomes were the incidence of GDM diagnosed with oral glucose tolerance test targeted at 24-28 gw and the change in fasting glucose between randomization and late pregnancy (mean 35.2 ± 0.9 gw). Insulin concentration, insulin resistance HOMA2-IR index, and pregnancy outcomes were determined, as were adverse effects related to the intervention. Analyses were by intent to treat. RESULTS: No differences were found among the intervention groups in the maternal and neonatal pregnancy outcomes or side effects related to the intervention (P > 0.05). The proportion of women with GDM (94 of 377; fish oil + placebo, 23 of 96, 24.0%; probiotics + placebo, 25 of 99, 25.3%; fish oil + probiotics, 26 of 91, 28.6%; and placebo + placebo, 20 of 91, 22.0%) and the change in glucose, insulin, or HOMA2-IR (n = 364) did not differ among the intervention groups (P > 0.11 for all comparisons). CONCLUSIONS: An intervention with fish oil and/or probiotics during pregnancy seemed to be both safe and well tolerated but conferred no benefits in lowering the risk of GDM or improving glucose metabolism in overweight and obese women.

Body composition measurement by air displacement plethysmography in pregnancy: Comparison of predicted versus measured thoracic gas volume.

OBJECTIVES: Body composition measurements with air displacement plethysmography (ADP) define body volume, which must be corrected for thoracic gas volume (TGV). We hypothesized that physiologic changes owing to pregnancy could affect the accuracy of predicted TGV and introduce errors into body composition measurements. METHODS: We investigated the effect of measuring versus predicting TGV on the accuracy of body composition calculations measured with ADP in overweight and obese pregnant women. The fat and fat-free masses of 110 women were determined with ADP with predicted and measured TGV. RESULTS: Measured TGV decreased from early to late pregnancy (P = 0.0002). Compared with measured TGV, predicted TGV was 6.3% higher during early gestation and 12.6% higher during late gestation (both P ≤ 0.001). The use of predicted instead of measured TGV in body composition calculations resulted in an overestimation of fat mass by 0.8% during the early stage, and 2.6% during the late stage of pregnancy (both P ≤ 0.001). CONCLUSIONS: Measuring TGV increases the accuracy of body composition measurement by ADP in overweight and obese women, particularly during the late stage of pregnancy.

Dietary quality influences body composition in overweight and obese pregnant women.

BACKGROUND & AIMS: Excessive adiposity and gestational weight gain (GWG) have been linked with maternal and offspring morbidity. We investigated the relation of maternal diet, physical activity and GWG on body composition in overweight and obese pregnant women. METHODS: Fat mass (FM) and fat free mass (FFM) of 110 overweight and obese pregnant women were measured by air displacement plethysmography in early and late pregnancy (mean 13.5 and 35.3 gestational weeks). At the same time points, the quality of overall diet was assessed by validated index of diet quality (IDQ) questionnaire (score < 10/15 denotes poor dietary quality and score ≥ 10/15 denotes good dietary quality), nutrient intakes by 3-day food diaries, and physical activity by questionnaire. Weight gain between early and late pregnancy was compared to the gestational weight gain guidelines issued by Institute of Medicine. RESULTS: Of the women, 77% gained more weight than recommended; this was related to greater dietary fat consumption (80 ± 21 g/day vs. 67 ± 11 g/day, p = 0.010) and greater increase in FM (2.7 ± 3.0 kg vs. -1.0 ± 2.4 kg, p < 0.001) compared to women with ideal GWG. Dietary protein intake (g) correlated positively with FFM at both time points (early pregnancy: r = 0.31, p < 0.002, late pregnancy: r = 0.39, p < 0.001). Women with higher dietary quality index score had more FFM, compared to women with lower dietary quality (early pregnancy FFM: 48.8 ± 5.8 kg vs. 45.8 ± 4.7 kg, p = 0.004, late pregnancy FFM: 56.1 ± 6.4 kg vs. 53.4 ± 5.6 kg, p = 0.025). No correlations were detected between total energy intake or physical activity and FM or FFM at early or late pregnancy. CONCLUSIONS: Body composition changes from early to late pregnancy were related to the amount of weight gained and overall dietary quality during pregnancy. Higher dietary quality and protein intake were associated with greater FFM, while dietary fat intake was related to excess weight gain. Identification of these dietary determinants of body composition and weight offers new targets for dietary counseling of pregnant women and thus potential for ensuing health benefits through reduced adiposity.

Amino acid profile in women with gestational diabetes mellitus treated with metformin or insulin.

AIMS: We compared the effects of metformin and insulin treatments of gestational diabetes mellitus (GDM) on amino acid metabolism. METHODS: 217 pregnant women diagnosed with GDM were randomized to receive either metformin or insulin. 1H nuclear magnetic spectroscopy was used to determine serum concentrations of alanine, glutamine, glycine, isoleucine, leucine, valine, histidine, phenylalanine, tyrosine, glucose and lactate at the time of diagnosis and at 36 gestational weeks (gw). RESULTS: Majority of the amino acid concentrations increased from 30 to 36 gw. The rise in alanine (16% vs. 8%, p < 0.0001), isoleucine (11% vs. 5%, p = 0.035) and lactate (29% vs. 14% p = 0.015) was larger in the metformin group compared to insulin group. Baseline alanine, glycine, isoleucine, leucine, valine and tyrosine were positively related to slightly earlier delivery. Alanine at 36 gw was positively associated with birth weight and glutamine with gestational hypertension or preeclampsia. Lactate at 36 gw was not associated with any adverse outcome. CONCLUSIONS: Compared to insulin metformin caused a greater increase in serum alanine, isoleucine and lactate concentrations. Although the observed differences in the metabolic variables were relatively small and not outright concerning, additional studies and follow-up data are required to ensure the safety of metformin use in pregnancy. The trial was registered in Clinicaltrials.gov, NCT01240785; http://clinicaltrials.gov/ct2/show/NCT01240785.

Increased intestinal permeability, measured by serum zonulin, is associated with metabolic risk markers in overweight pregnant women.

BACKGROUND: Increased intestinal permeability with subsequent metabolic endotoxemia, i.e., elevated circulating levels of bacterial lipopolysaccharide, LPS, has been introduced as a novel initiator of obesity related metabolic disturbances in non-pregnant individuals. The objective was to investigate the extent to which intestinal permeability, measured by serum zonulin concentration, is related to metabolic endotoxemia and metabolic risk markers in overweight pregnant women. METHODS: This was a cross-sectional study including 100 pregnant overweight women in early pregnancy. Serum zonulin was analyzed using ELISA, and markers for metabolic endotoxemia (LPS), inflammation (high-sensitive C-reactive protein and glycoprotein acetylation GlyA), glucose metabolism (fasting glucose and insulin), and lipid metabolism were measured. RESULTS: Higher serum zonulin concentration associated positively with LPS (P=0.02), inflammatory markers (P<0.001), insulin (P<0.001), insulin resistance (P<0.001), and triglycerides (P=0.001), and negatively with insulin sensitivity (P=0.001) (ANOVA with Tukey's corrections or Kruskal-Wallis nonparametric test with Bonferroni correction for zonulin quartiles). All the observed associations were confirmed (P<0.015) in a linear regression model adjusted with potential confounding factors. Both LPS and GlycA showed positive relationship with insulin resistance, serum insulin, triglycerides, total and LDL-cholesterol and negative relationship with insulin sensitivity (P≤0.03) in the univariate linear regression. Positive relationship was also found between LPS and HDL-cholesterol (P=0.03). CONCLUSIONS: Our findings suggest that increased serum zonulin concentration, i.e., increased intestinal permeability, contributes to metabolic endotoxemia, systemic inflammation, and insulin resistance in overweight pregnant women. By reinforcing intestinal barrier, it may be possible to manipulate maternal metabolism during pregnancy with subsequent health benefits.

The effects of metformin treatment of gestational diabetes on maternal weight and glucose tolerance postpartum--a prospective follow-up study.

INTRODUCTION: Metformin seems to reduce gestational weight gain compared with insulin in women with gestational diabetes (GDM). Women with GDM requiring insulin are more likely to develop abnormal glucose tolerance postpartum than women treated with diet only. In this prospective follow-up study of a randomized clinical trial, we investigated the effect of metformin treatment in women with GDM on weight gain and glucose tolerance postpartum. MATERIALS AND METHODS: Women with GDM with two or more pathologic glucose values at 2-h 75-g oral glucose tolerance test (OGTT) were recruited. Those needing medication to achieve sufficient glycemic control were randomized at 22-34 weeks of gestation to either metformin (n = 110) or insulin (n = 107) treatment until delivery. A third GDM group (n = 128) requiring no medication had only diet treatment. Weight, OGTT and glycosylated hemoglobin (HbA1c) were determined at 6-8 weeks and 1 year postpartum. RESULTS: At least one postpartum visit was attended by 104, 101 and 120 women in the metformin, insulin and diet-only groups, respectively. No significant differences were found in the change of weight, HbA1c or OGTT glucose values between the groups during the study (p ≥ 0.121 in all comparisons). One year postpartum the diet-only group had less impaired glucose tolerance compared with the metformin and insulin groups (7.1%, 19.1% and 15.6%, respectively; overall p = 0.039) and a lower incidence of diabetes (p = 0.027). CONCLUSIONS: Short-term metformin therapy does not affect weight, HbA1c or OGTT glucose values postpartum compared with insulin or diet-only treatments. Women with GDM requiring no medication are least likely to develop impaired glucose tolerance or diabetes postpartum.