妊娠期糖尿病营养相关危险因素病例对照研究

目的:探讨妊娠期糖尿病（GDM）营养相关危险因素,为孕期合理膳食及健康管理提供依据。 目的　探讨妊娠糖尿病（gestational diabetes mellitus,GDM）营养相关危险因素,为孕期合理膳食及健康管理提供依据。方法　纳入2014年12月至2015年5月就诊于北京协和医院产科且在孕24~28周完成糖耐量筛查的25~45岁孕妇。采取多阶段连续等比例抽样,确诊GDM新发病例150例为病例组,同期就诊非GDM 150例为对照组。利用食物频率问卷对其一般情况及膳食状况进行调查。采用Logistic回归筛选GDM营养相关危险因素。结果　单因素分析显示,2型糖尿病家族史、孕前体重指数（body mass index, BMI）、GDM史、水果摄入量、精制谷物所占比例、每日肉类摄入量、高脂食品摄入频率、每日食盐摄入量、每日烹调油摄入量、每日坚果摄入量、在外就餐频率、含糖饮料摄入及体力活动状况与GDM之间相关性具有统计学意义（P＜0.05）。多因素Logistic回归分析显示,孕前BMI (OR=1.628, 95% CI: 1.079~2.456)、2型糖尿病家族史 (OR=1.761, 95% CI: 1.001~3.096)、GDM史(OR=7.855, 95% CI: 1.982~31.125)、水果摄入量(OR=1.457, 95% CI: 1.148~1.849)、精制谷物(OR=1.350, 95% CI:1.008~1.808)、高脂食品(OR=1.398, 95% CI: 1.066~1.833)及缺乏体力活动(OR=1.257, 95% CI: 1.111~1.422)与GDM具有相关性(P＜0.05)。结论　孕前BMI异常、2型糖尿病家族史、GDM史、水果摄入过量、主食过于精制、经常摄入高脂食品及缺乏体力活动可增加GDM发病风险。     

Persistence of Risk for Type 2 Diabetes After Gestational Diabetes Mellitus

OBJECTIVEGestational diabetes mellitus complicates ∼6% of pregnancies and strongly predicts subsequent type 2 diabetes. It has not been fully elucidated how risk depends on the number of affected pregnancies or how long the excess risk persists.RESEARCH DESIGN AND METHODSWe assessed reproductive histories in relation to risk of type 2 diabetes using a nationwide cohort of 50,884 women. Among participants who initially did not have diabetes, 3,370 were diagnosed with diabetes during 10 years of follow-up. We used Cox proportional hazards models that allowed risk to depend on age, cumulative number of pregnancies with gestational diabetes mellitus, and time since the most recent affected pregnancy, adjusting for BMI, educational level, and race/ethnicity.RESULTSHistory of one or more pregnancies with gestational diabetes mellitus predicted elevated age-specific risk of type 2 diabetes, with a hazard ratio of 3.87 (95% CI 2.60–5.75) 6–15 years after an affected pregnancy. Risk increased steeply with multiple affected pregnancies. The age-specific associations attenuated over time after an affected pregnancy, with an estimated 24% reduction of the hazard ratio per decade. Risk remained elevated, however, for >35 years.CONCLUSIONSGestational diabetes mellitus predicted markedly increased rates of type 2 diabetes. Relative risk increased substantially with each additional affected pregnancy. The estimated hazard ratio declined with time after a pregnancy with gestational diabetes mellitus but remained elevated for >35 years. Women recalling a history of gestational diabetes mellitus should be screened regularly for type 2 diabetes, even late in life.     

Prepregnancy SHBG Concentrations and Risk for Subsequently Developing Gestational Diabetes Mellitus

OBJECTIVE

Lower levels of sex hormone–binding globulin (SHBG) have been associated with increased risk of diabetes among postmenopausal women; however, it is unclear whether they are associated with glucose intolerance in younger women. We examined whether SHBG concentrations, measured before pregnancy, are associated with risk of gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

This was a nested case-control study among women who participated in the Kaiser Permanente Northern California Multiphasic Health Check-up examination (1984–1996) and had a subsequent pregnancy (1984–2009). Eligible women were free of recognized diabetes. Case patients were 256 women in whom GDM developed. Two control subjects were selected for each case patient and were matched for year of blood draw, age at examination, age at pregnancy, and number of intervening pregnancies.

RESULTS

Compared with the highest quartile of SHBG concentrations, the odds of GDM increased with decreasing quartile (odds ratio 1.06 [95% CI 0.44–2.52]; 2.33 [1.07–5.09]; 4.06 [1.90–8.65]; P for trend < 0.001), after adjusting for family history of diabetes, prepregnancy BMI, race/ethnicity, alcohol use, prepregnancy weight changes, and homeostasis model assessment of insulin resistance. Having SHBG levels below the median (<64.5 nmol/L) and a BMI ≥25.0 kg/m² was associated with fivefold increased odds of GDM compared with normal-weight women with SHBG levels at or above the median (5.34 [3.00–9.49]).

CONCLUSIONS

Low prepregnancy SHBG concentrations were associated with increased risk of GDM and might be useful in identifying women at risk for GDM for early prevention strategies.     

视黄醇结合蛋白4在妊娠期糖尿病患者中的表达及其临床意义

目的：分析视黄醇结合蛋白4（retinol-binding protein4,RBP4）在妊娠期糖尿病患者和健康孕妇血清中的浓度差异及其与临床、病理特征的关系。方法：检测18例妊娠期糖尿病（GDM）和212例健康孕妇血清中RBP4的表达,分别于孕18周、孕20周、孕28周及产后8周空腹收集血清。利用酶联免疫吸附实验（ELISA）检测血清RBP4的表达。用HOMA-IR（homeosta-sis model assessment）模型评价胰岛素抵抗程度。结果：所有孕妇血清RBP4水平在产前各时间点呈时间依赖性升高。产后8周（中位数,15.35μg/mL;四分位数,11.32～27.85μg/mL）孕妇血清RBP4水平均下降。孕20周（中位数,45.72μg/mL;四分位数,33.34～58.69μg/mL）、孕28周（中位数,52.34μg/mL;四分位数,42.65～73.54μg/mL）时,GDM患者血清RBP4水平高于健康孕妇（孕20周：中位数,19.13μg/mL;四分位数,15.23～22.65μg/mL;孕28周：中位数,42.54μg/mL;四分位数,24.56～55.21μg/mL）。孕18周（中位数,16.80μg/mL;四分位数,14.58～28.67μg/mL）和产后8周（中位数,15.35μg/mL;四分位数,11.32～27.85μg/mL）,GDM患者血清RBP4水平和健康孕妇无显著差异（孕18周：中位数,15.78μg/mL;四分位数,10.23～19.35μg/mL;产后8周：中位数,13.54μg/mL;四分位数,9.21～18.35μg/mL）。孕20周时血清RBP4水平和HOMA-IR（相关系数r=0.872;P=0.002）、体质量指数、血清三酰甘油和低密度脂蛋白呈正相关,和高密度脂蛋白呈负相关。结论：孕20周血清RBP4水平可能成为GDM的早期诊断指标。     

Exercise and the Prevention of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is associated with pregnancy complications and fetal complications, as well as long-term health consequences for women and their offspring. Pregnancy is a pseudodiabetogenic state of increasing insulin resistance and decreasing insulin sensitivity, which places a woman at increased risk for GDM. Exercise facilitates the uptake of blood glucose into cells to be used for energy, making exercise a potential strategy in preventing GDM. Extensive evidence has found an association between consistent moderate to vigorous exercise in pregnancy and the prevention of GDM. With close attention to risk factors, maternity care nurses and other health care providers can play an important role in educating pregnant women on exercise recommendations to help them achieve optimal health and wellness.     

妊娠期糖尿病合并感染的相关因素分析及护理对策

目的　探讨妊娠期糖尿病 (GDM)合并感染的特点 ,分析引起感染的危险因素 ,寻找控制感染的护理措施。方法　随机抽取在我院产前检查并住院分娩的妊娠期糖尿病孕妇 40例 (GDM组 )和正常孕妇 40例 (对照组 ) ,并收集相关资料。结果　 GDM组发生感染 2 5例 ,感染率为 6 2 .5 % ;对照组发生感染 4例 ,感染率为 10 % (P <0 .0 0 1)。GDM感染主要以尿路感染、呼吸道感染、霉菌性阴道炎为主。结论　针对 GDM发生感染率高的特点 ,对主要危险因素进行综合管理 ,重点监控 ,加强消毒隔离工作 ,严格落实护理措施     

妊娠期糖尿病的筛查与处理

目的探讨妊娠期糖尿病(GDM)的诊断及处理方法。方法对2311例孕妇行葡萄糖筛查,诊断GDM57例作为观察组,选取同期符合GDM诊断标准未经正规治疗的49例作为对照组,比较两组的母儿结局。结果观察组羊水过多、巨大儿、高胆红素血症、新生儿呼吸窘迫综合征、围生儿死亡率等均明显低于对照组,差异有显著性(P<0.05)。结论及早诊断、积极治疗,可改善母儿预后。     

1 849例孕妇妊娠期糖尿病筛查结果临床分析

目的 观察孕24～28周孕妇口服无水葡萄糖耐量试验的结果,应用美国糖尿病协会（ADA）和国际妊娠并发糖尿病研究组织（IADPSG）推荐的妊娠糖尿病（GDM）诊断标准对筛查结果的诊断率进行临床分析.方法 选自2012年4月～2013年4月在产科门诊就诊的1 849例孕24～28周产前检查妇女,口服75 g葡萄糖进行葡萄糖耐量试验（OGTT）,分别于空腹、服用葡萄糖后1h和2h采集静脉血,观察空腹、PG1h,PG2h 3点葡萄糖水平,根据ADA和IADPSG两种诊断标准计算诊断率.不同标准间的诊断率比较采用卡方配对检验.结果 当空腹血糖介于4.01～5.09 mmol/L和5.1～6.09 mmol/L时,两种标准的GDM诊断率分别为12.8％ vs 9.1％,48.2％ vs 100％,其差异有统计学显著性意义（x2=54.90～137.28,P值均＜0.05）,采用IADPSG标准,GDM诊断率高达18.7％,较ADA标准诊断率6.49％升高了188％,如将IADPSG标准的血糖异常个数改为2个,阳性例数为156例,GDM诊断率为8.44％,与ADA标准诊断率6.49％的差距明显缩小.不同年龄组GDM诊断率比较差异均有统计学显著性意义（x2=12.9～256.8,P值均＜0.05）,并且随年龄的增加,GDM诊断阳性率有增高的趋势.结论 更为敏感的IADPSG诊断标准使得GDM的诊断率显著增高,其主要原因是诊断标准中超过血糖阈值的个数从2点变成1点所致.选择适当的诊断标准对GDM的诊断有着重要意义,所以应尽快制定国内诊断标准,加强对GDM的早诊断、早治疗,降低母婴并发症,改善妊娠结局.     

妊娠期糖尿病与血清胎球蛋白A的关系

目的:探讨妊娠期糖尿病(GDM)患者血清中胎球蛋白A(Fetuin-A)、脂联素及游离脂肪酸(FFA)水平的变化.方法:用酶链免疫吸附法(ELISA)测定GDM患者正常孕妇及正常人群外周血血清中Fetuin-A、脂联素及FFA水平.结果:GDM患者血清中Fetuin-A及FFA的水平显著高于非妊娠和健康妊娠妇女(P＜0.05).而其血清糖化血红蛋白和脂联素水平差异无统计学意义.结论:血清Fetuin-A联合FFA能更好地反映体内的胰岛素抵抗状态.     

A Prospective Study of Heart Disease in Diabetes Mellitus

Six hundred and twenty-five patients with diabetes mellituswere studied by standardised clinical methods, resting andexerciseelectrocardiography (ECG) and digitised echocardio-graphy todetermine the prevalence of coronary and non-coronary heartdisease. Clincial evidence of coronary artery disease (anginaand infarction) was present in 110 (18 per cent) normotensivepatients. Hypertension (blood pressure >165/95 mmHg) waspresent in 172 (27 per cent) of whom 32 had cardiac symptoms.Heart failure or left ventricular dilatation was seen in 18of whom 11 had either hypertension or coronary artery diseaseand six asymptomatic patients had unexplained ventricular hypertrophy. Echocardiograms in 245 of 290 asymptomatic patients with normalECG showed that relaxation was prolonged (p<0.001) and mitralvalve opening delayed (p<0.001) from normal especially inthose with severe microangiopathy (proliferative retinopathyand/or heavy proteinuria). The peak rates of cavity dimensionincrease and posterior wall thinning were reduced from normal(both p<0.001) and patients with severe microangiopathy hadthe most marked changes. Redivision of these 245 diabetics byabnormalities of left ventricular function showed that 147 hadnormal function in whom only one of23 (random 15 per cent sample)had a positive exercise ECG. Prolonged relaxation or delayedmitral valve opening alone (anon-specific abnormality) was presentin 41 and only three of 28 had a positive exercise ECG. Thirty-onehad delayed mitral valve opening with inco-ordinate relaxation(abnormalities very suggestive of coronary artery disease) ofwhom 20 of 29 had a positive exercise ECG. Twenty-six had delayedmitral valve opening with slow cavity dimension increase orwall thinning (without hypertrophy) of whom 21 of 25 had a negativeexercise ECG. This is a relatively specific abnormality similarto that found in left ventricular hypertrophy. Coronary artery disease is common in symptomatic and asymptomaticforms in diabetes mellitus. Non-coronary left ventricular diseases,such as dilation and hypertrophy, are probably no more commonin diabetics than non-diabetics. A small number of diabeticswith severe microangiopathy had abnormal relaxation and reducedpeak rate of dimension increase or wallthinning which may representleft ventricular disease due to microangiopathy.     

Pregravid Liver Enzyme Levels and Risk of Gestational Diabetes Mellitus During a Subsequent Pregnancy

OBJECTIVE

Liver enzymes are independent predictors of type 2 diabetes. Although liver fat content correlates with features of insulin resistance, a risk factor for developing gestational diabetes mellitus (GDM), the relationship between liver enzymes and GDM is unclear. The objective of this study was to assess whether pregravid liver enzyme levels are associated with subsequent risk of GDM.

RESEARCH DESIGN AND METHODS

A nested case-control study was conducted among women who participated in the Kaiser Permanente Northern California multiphasic health checkup (1984–1996) and had a subsequent pregnancy (1984–2009). Case patients were 256 women who developed GDM. Two control subjects were selected for each case patient and matched for year of blood draw, age at examination, age at pregnancy, and number of intervening pregnancies.

RESULTS

Being in the highest quartile versus the lowest quartile of γ-glutamyl transferase (GGT) levels was associated with a twofold increased risk of subsequent GDM (odds ratio 1.97 [95% CI 1.14–3.42]), after adjusting for race/ethnicity, prepregnancy BMI, family history of diabetes, and alcohol use. This result was attenuated after adjusting for homeostasis model assessment of insulin resistance (HOMA-IR), fasting status, and rate of gestational weight gain. There was significant interaction between GGT and HOMA-IR; the association with GGT was found among women in the highest tertile of HOMA-IR. Aspartate aminotransferase and alanine aminotransferase were not associated with increased GDM risk.

CONCLUSIONS

Pregravid GGT level, but not alanine aminotransferase or aspartate aminotransferase level, predicted the subsequent risk of GDM. Markers of liver fat accumulation, such as GGT level, are present years before pregnancy and may help to identify women at increased risk for subsequent GDM.     

Determinants of Maternal Triglycerides in Women With Gestational Diabetes Mellitus in the Metformin in Gestational Diabetes (MiG) Study

OBJECTIVE

Factors associated with increasing maternal triglyceride concentrations in late pregnancy include gestational age, obesity, preeclampsia, and altered glucose metabolism. In a subgroup of women in the Metformin in Gestational Diabetes (MiG) trial, maternal plasma triglycerides increased more between enrollment (30 weeks) and 36 weeks in those treated with metformin compared with insulin. The aim of this study was to explain this finding by examining factors potentially related to triglycerides in these women.

RESEARCH DESIGN AND METHODS

Of the 733 women randomized to metformin or insulin in the MiG trial, 432 (219 metformin and 213 insulin) had fasting plasma triglycerides measured at enrollment and at 36 weeks. Factors associated with maternal triglycerides were assessed using general linear modeling.

RESULTS

Mean plasma triglyceride concentrations were 2.43 (95% CI 2.35–2.51) mmol/L at enrollment. Triglycerides were higher at 36 weeks in women randomized to metformin (2.94 [2.80–3.08] mmol/L; +23.13% [18.72–27.53%]) than insulin (2.65 [2.54–2.77] mmol/L, P = 0.002; +14.36% [10.91–17.82%], P = 0.002). At 36 weeks, triglycerides were associated with HbA_1c (P = 0.03), ethnicity (P = 0.001), and treatment allocation (P = 0.005). In insulin-treated women, 36-week triglycerides were associated with 36-week HbA_1c (P = 0.02), and in metformin-treated women, they were related to ethnicity.

CONCLUSIONS

At 36 weeks, maternal triglycerides were related to glucose control in women treated with insulin and ethnicity in women treated with metformin. Whether there are ethnicity-related dietary changes or differences in metformin response that alter the relationship between glucose control and triglycerides requires further study.Maternal metabolism in late pregnancy is catabolic, with increasing insulin resistance, decreased adipose tissue lipoprotein lipase (LPL) activity, and increased lipolysis (1). These processes combine to ensure the availability of maternal fuels such as glucose, fatty acids, and ketone bodies for fetal use (1). It is recognized that gestational age, maternal obesity (2), and preeclampsia (3) are associated with increases in lipids during pregnancy. Gestational diabetes mellitus (GDM) is also associated with abnormalities in maternal lipid metabolism (4–6), which may contribute to the elevated fat mass seen at birth in infants of women with GDM (7–10).Maternal glucose control and the pharmacological therapies used for treatment of GDM have the potential to influence these changes in maternal lipids (11). Insulin suppresses adipose tissue lipolysis and might be expected to reduce circulating triglycerides (12). Metformin reduces insulin resistance, but it has also been suggested to influence lipid metabolism (13), independent of glycemic control. In type 2 diabetes, metformin treatment is associated with a reduction in plasma triglyceride, total cholesterol, LDL cholesterol (13), and VLDL cholesterol concentrations (14). Metformin treatment in type 2 diabetes is also associated with increases in LPL mass level and LDL cholesterol particle size (15) and with a reduction in the release of free fatty acids from adipose tissue (16).We have recently examined maternal lipids in the Metformin in Gestational Diabetes (MiG) trial and found that maternal fasting plasma triglycerides and measures of glucose control at 36 weeks were the strongest predictors of customized birth weight >90th percentile (17). Interestingly, triglycerides increased more from randomization to 36 weeks'' gestation in women allocated to metformin than in those allocated to treatment with insulin, but there was no difference in customized birth weights or other neonatal anthropometry measures between the groups; there were also no differences in cord blood triglycerides (17). The aim of this study was to examine the known and putative determinants of maternal triglyceride concentrations and determine whether the difference seen in maternal plasma triglycerides at 36 weeks was due to treatment or other factors that may have differed between treatment groups.     

Mild Gestational Diabetes Mellitus and Long-Term Child Health

OBJECTIVETo evaluate whether treatment of mild gestational diabetes mellitus (GDM) confers sustained offspring health benefits, including a lower frequency of obesity.RESULTSFive hundred of 905 eligible offspring (55%) were enrolled. Maternal baseline characteristics were similar between the follow-up treated and untreated groups. The frequencies of BMI ≥95th (20.8% and 22.9%) and 85th (32.6% and 38.6%) percentiles were not significantly different in treated versus untreated offspring (P = 0.69 and P = 0.26). No associations were observed for BMI z score, log waist circumference, log triglycerides, HDL cholesterol, blood pressure, or log HOMA-estimated insulin resistance (HOMA-IR). The effect of treatment was different by sex for fasting glucose and log HOMA-IR (P for interaction = 0.002 and 0.02, respectively) but not by age-group (5–6 and 7–10 years) for any outcomes. Female offspring of treated women had significantly lower fasting glucose levels.CONCLUSIONSAlthough treatment for mild GDM has been associated with neonatal benefits, no reduction in childhood obesity or metabolic dysfunction in the offspring of treated women was found. However, only female offspring of women treated for mild GDM had lower fasting glucose.     

Physical Activity Before and During Pregnancy and Risk of Gestational Diabetes Mellitus: A meta-analysis

OBJECTIVE

Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy and is associated with a substantially elevated risk of adverse health outcomes for both mothers and offspring. Physical activity may contribute to the prevention of GDM and thus is crucial for dissecting the vicious circle involving GDM, childhood obesity, and adulthood obesity, and diabetes. Therefore, we aimed to systematically review and synthesize the current evidence on the relation between physical activity and the development of GDM.

RESEARCH DESIGN AND METHODS

Medline, EMBASE, and Cochrane Reviews were searched from inception to 31 March 2010. Studies assessing the relationship between physical activity and subsequent development of GDM were included. Characteristics including study design, country, GDM diagnostic criteria, ascertainment of physical activity, timing of exposure (prepregnancy or early pregnancy), adjusted relative risks, CIs, and statistical methods were extracted independently by two reviewers.

RESULTS

Our search identified seven prepregnancy and five early pregnancy studies, including five prospective cohorts, two retrospective case-control studies, and two cross-sectional study designs. Prepregnancy physical activity was assessed in 34,929 total participants, which included 2,813 cases of GDM, giving a pooled odds ratio (OR) of 0.45 (95% CI 0.28–0.75) when the highest versus lowest categories were compared. Exercise in early pregnancy was assessed in 4,401 total participants, which included 361 cases of GDM, and was also significantly protective (0.76 [95% CI 0.70–0.83]).

CONCLUSIONS

Higher levels of physical activity before pregnancy or in early pregnancy are associated with a significantly lower risk of developing GDM.Gestational diabetes mellitus (GDM) is one of the most common complications of pregnancy, affecting ∼7% of all pregnancies in the U.S. (i.e., >200,000 cases annually) (1), and this number is increasing as the prevalence of obesity among women at reproductive age escalates (2–4). GDM is associated with a significantly elevated risk for short-term and long-term complications for both mothers and offspring. Women with GDM have an increased risk for perinatal morbidity and impaired glucose tolerance and type 2 diabetes in the years after pregnancy (5,6). Children of women with GDM are more likely to be obese and have impaired glucose tolerance and diabetes in childhood and early adulthood (1). In a recent meta-analysis of randomized trials on the effect of treatment for GDM, various interventions for blood glucose control, including diet, glucose monitoring, insulin use, and pharmaceutical interventions, did not significantly reduce the risk for adverse perinatal and neonatal end points, including cesarean section and perinatal or neonatal death (7). Collectively, these data indicate that prevention of GDM altogether could be crucial for avoiding its associated adverse health outcomes.Physical activity has long been known for its role in improving glucose homeostasis through its direct or indirect impact on insulin sensitivity via several mechanisms. For instance, physical activity has independent effects on glucose disposal by increasing both insulin-mediated and non–insulin-mediated glucose disposal (8,9). Physical activity can also exert long-term effects on improvement in insulin sensitivity through increased fat-free mass (10). Furthermore, the benefits of preventing or delaying the onset of type 2 diabetes among nonpregnant individuals have been reported repeatedly (11,12). Therefore, physical activity may have the potential for preventing GDM and related adverse health outcomes. However, evidence for its impact on GDM has not been systematically synthesized. The aim of this systematic review and meta-analysis was to assemble the current evidence for the relationship between physical activity and the development of GDM.     

Association of Maternal Folate and Vitamin B12 in Early Pregnancy With Gestational Diabetes Mellitus: A Prospective Cohort Study

OBJECTIVETo investigate the association of folate and vitamin B₁₂ in early pregnancy with gestational diabetes mellitus (GDM) risk.RESEARCH DESIGN AND METHODSThe data of this study were from a subcohort within the Shanghai Preconception Cohort Study. We included pregnancies with red blood cell (RBC) folate and vitamin B₁₂ measurements at recruitment (between 9 and 13 gestational weeks) and those with three samples available for glucose measurements under an oral glucose tolerance test. GDM was diagnosed between 24 and 28 weeks’ gestation. Odds ratio (OR) and 95% CI of having GDM was used to quantify the association.RESULTSA total of 1,058 pregnant women were included, and GDM occurred in 180 (17.01%). RBC folate and vitamin B₁₂ were significantly higher in pregnancies with GDM than those without GDM (P values were 0.045 and 0.002, respectively) and positively correlated with 1-h and 2-h serum glucose. Daily folic acid supplementation in early pregnancy increases the risk of GDM; OR (95% CI) was 1.73 (1.19–2.53) (P = 0.004). Compared with RBC folate <400 ng/mL, pregnancies with RBC folate ≥600 ng/mL were associated with ∼1.60-fold higher odds of GDM; the adjusted OR (95% CI) was 1.58 (1.03–2.41) (P = 0.033). A significant trend of risk effect on GDM risk across categories of RBC folate was observed (P_trend = 0.021). Vitamin B₁₂ was significantly associated with GDM risk (OR 1.14 per 100 pg/mL; P = 0.002). No significant association of serum folate and percentile ratio of RBC folate/vitamin B₁₂ with GDM was observed.CONCLUSIONSHigher maternal RBC folate and vitamin B₁₂ levels in early pregnancy are significantly associated with GDM risk, while the balance of folate/vitamin B₁₂ is not significantly associated with GDM.