Screening and testing for gestational diabetes mellitus

Optimal maternal neck and waist circumference cutoff values for prediction of gestational diabetes mellitus at the first trimester in Turkish population; a prospective cohort study

Aims: To investigate if the maternal neck (NC) and waist (WC) circumferences measured in the first trimester of pregnancy have a predictive value in diagnosing gestational diabetes mellitus (GDM).Materials and methods: In this prospective study NC and WC of pregnant women were measured at 11-14th weeks. GDM was evaluated with a two-step oral glucose tolerance test at 24-28th weeks.Result: A total of 525 women were recruited; 49(9%) developed GDM. NC was positively correlated with WC (r: 0.583, p < .001), BMI (r: 0.533, p < .001), age (r: 0.123, p = .002), parity (r: 0.170, p < .001), and 50 g OGTT levels (r: 0.206, p < .001). Regarding the area under receiver operating characteristic (ROC) curve (AUC) analysis of NC and WC for predicting GDM were 0.585 (95% confidence interval (CI): 0.50-0.66, p = .043), and 0.693 (95%CI: 0.61-0.76, p < .001). The optimal cut off level of maternal NC was >38.5 cm, with 69% sensitivity and 45% specificity, and WC was >84.50 cm with a sensitivity of 78% and a specificity of 54%. Increased WC >84.50 cm (OR: 3.58, 95% CI:1.77-7.27; p < .001) and age >25 (OR: 3.05, 95% CI:1.38-6.72; p = .006) were independent predictors for the development of GDM adjusted for age, gravidity, parity, BMI, and NC.Conclusion: Maternal NC and WC were significantly higher in women with GDM; however, only maternal WC was a significant predictive marker for GDM in low-risk pregnant women.

Maternal serum glycosylated hemoglobin and fasting plasma glucose predicts gestational diabetes at the first trimester in Turkish women with a low-risk pregnancy and its relationship with fetal birth weight; a retrospective cohort study

OBJECTIVE

To examine the accuracy of maternal serum glycosylated hemoglobin (HbA1c) and fasting plasma glucose (FPG) levels in predicting gestational diabetes at the first trimester in Turkish women with a low-risk pregnancy and its relationship with fetal birth weight.

METHODS

This cohort study was conducted retrospectively in a tertiary referral hospital from January 2010 to January 2017. HbA1c and FPG serum concentrations were measured in 670 pregnant women at the first-trimester screening. HbA1c and FPG concentrations of women who subsequently developed gestational diabetes mellitus (GDM) were compared to those who did not, and its relationship with fetal weight was investigated.

RESULTS

First-trimester screening was performed on 608 pregnant women, of whom 69 (11.3%) women had developed GDM. Median HbA1c and FPG concentrations were significantly higher in women developing GDM (n = 69) in comparison to those with uncomplicated pregnancies (n = 539) (5.31 ± 0.58% versus 5.01 ± 0.45%, p < .001 and 89.74 ± 8.71% versus 84.09 ± 9.16%, p < .001, respectively). The cut-off value calculated with the highest Youden index was HbA1c levels above 5.6% with a sensitivity of 34.78%, specificity of 89.8%, with a diagnostic accuracy of 83.55%, and FPG levels above 86.85 mg/dl with a sensitivity of 69.57%, specificity of 61.78%, with a diagnostic accuracy of 62.66%. The calculated odds ratio (OR) for HbA1c > 5.6% and FPG > 86 mg/dl were 4.69 (95% CI: 2.66-8.29), and 3.7 (95% CI: 2.15-6.35), respectively. HbA1c and FPG combined had improved the predictive capability for GDM (OR: 7.26, 95% CI: 3.71-14.19). According to correlation analyses, a noteworthy positive correlation was found between HbA1c and, FPG, 50 g GCT, age, BMI, parity, and birth weight. However, there was no correlation between FPG and birth weight.

CONCLUSION

Diagnostic accuracy of HbA1c for GDM prediction in Turkish women with a low-risk pregnancy is 83.55% with a very good negative predictive value of 91.49%. HbA1c and FPG combined enhanced the predictive capability for GDM. In addition, there is a positive relationship between HbA1c and 50 g GCT, and birth weight. However, to suggest HbA1c as a potential screening test for gestational diabetes mellitus, further research is warranted.

Prediction of gestational diabetes mellitus in the first trimester: comparison of maternal fetuin-A, N-terminal proatrial natriuretic peptide, high-sensitivity C-reactive protein, and fasting glucose levels

OBJECTIVE

We investigated the utility of maternal fetuin-A, N-terminal proatrial natriuretic peptide (pro-ANP), high-sensitivity C-reactive protein (hs-CRP), and fasting glucose levels at 11-14 gestation weeks for predicting pregnancies complicated by gestational diabetes mellitus (GDM).

SUBJECTS AND METHODS

This prospective cohort study included 327 low-risk pregnant women who completed antenatal follow-up at a tertiary research hospital between January and April 2014. Maternal blood samples were collected between 11-14 gestational weeks in the first trimester of pregnancy and then stored at -80 °C until further analyses. During follow-up, 29 (8.8%) women developed GDM. The study population was compared 1:2 with age- and body mass index-matched pregnant women who did not develop GDM (n = 59). Fasting plasma glucose (FPG) levels and serum fetuin-A, pro-ANP, and hs-CRP levels were measured using automated immunoassay systems.

RESULTS

There was a significant negative correlation between fetuin-A and hs-CRP (CC = -0.21, p = 0.047) and a positive correlation between FPG and hs-CRP (CC = 0.251, p = 0.018). The areas under the receiver operating characteristic curve for diagnosing GDM were 0.337 (p = 0.013), 0.702 (p = 0.002), and 0.738 (p < 0.001) for fetuin-A, hs-CRP, and FPG, respectively. The optimal cut-off values were > 4.65, < 166, and > 88.5 mg/dL for maternal hs-CRP, fetuin-A, and FPG, respectively.

CONCLUSION

Reduced fetuin-A, elevated hs-CRP, and FPG levels in women in the first trimester can be used for the early detection of GDM. Further research is needed before accepting these biomarkers as valid screening tests for GDM.

Relationship maternal subcutaneous adipose tissue thickness and development of gestational diabetes mellitus

Objective

We investigated whether the ultrasonographic measurement of maternal subcutaneous adipose tissue (SAT) thickness in the second trimester played a role in predicting gestational diabetes.

Materials and methods

This was a prospective cross-sectional study in which 223 women were classified as healthy (n = 177) or as gestational diabetes (n = 46) on the basis of a negative or positive two-step oral Glucose Challenge Test (GCT), respectively. The depth of the abdominal SAT was evaluated by two-dimensional ultrasonography. Body mass index (BMI), waist circumference (WC), and waist/hip ratio were determined.

Results

There was a positive strong significant correlation between a 50-g GCT level and BMI, WC, and SAT thickness (p < 0.001). Receiver-operating characteristic curve analysis showed SAT thickness above 16.75 mm predicted gestational diabetes mellitus (GDM) with a sensitivity of 71.7%, a specificity of 57.1%, a positive predictive value of 32.3%, and a negative predictive value of 87.6%. There was a good correlation between SAT, BMI, and WC.

Conclusion

Increased SAT, BMI, and WC measurements may be helpful in predicting the risk of the development of GDM in pregnant women.

Gestational diabetes: Validity of ADA and WHO diagnostic criteria using NDDG as the reference test

OBJECTIVE

Evidence is provided to clinicians and decision makers on the validity of ADA and WHO tests based on NDDG criteria for gestational diabetes.

MATERIALS AND METHODS

During 18 months, all pregnant women attending a University Hospital underwent a 50-g, 1-h NDDG GCT for universal screening (n = 1092). The following appointment consisted of a 75-g, 2-h GTT (WHO test), independently of the prior result. Women with an abnormal 50-g and/or an abnormal 75-g, received a 100-g, 3-h GTT; subjects with only one abnormal 3-h GTT value were not included in the accuracy analysis. Women whose diagnosis followed NDDG criteria received treatment. Obstetricians were not aware of ADA/WHO results.

RESULTS

ADA sensitivity was 100% (95%CI 98.6, 100) and specificity, 98.1% (95%CI 97.6, 98.6), whereas WHO sensitivity was 57.6% (95%CI 55.9, 59.2) and specificity, 85.1% (95%CI 84.7, 85.6). ADA results remained similar independently of obesity and age, but performed better with a family history of diabetes. Accuracy of WHO improved under selective screening, still the false negative rate ranged 40-56%.

CONCLUSIONS

We recommend replicating this validation process in other health service settings. Although WHO test is easier and less expensive than NDDG or ADA, caution is needed before deciding employment of such criteria in pregnant women.

Fasting or two-hour postprandial plasma glucose levels in early months of pregnancy as screening tools for gestational diabetes mellitus developing in later months of pregnancy

PURPOSE

The present study was done to find out whether the fasting or 2-hour postprandial plasma glucose (PPPG) levels in early months of pregnancy can be used as screening tools for gestational diabetes mellitus (GDM) developing in later months of pregnancy.

BASIC PROCEDURE

Fasting and 2-hour PPPG levels were measured in the early months of pregnancy in 246 women attending the antenatal clinic of the author. All of the women underwent glucose challenge tests with 50 grams of glucose at 24-28 weeks and if the value exceeded 140 mg%, a three-hour oral glucose tolerance test (OGTT) with 100 grams of glucose was performed to diagnose GDM.

MAIN FINDINGS

The present study found that the incidence of GDM was 10.5% in the third trimester. Statistical analysis did not show any correlation between fasting and the PPPG values in the early months and GDM in later months of pregnancy.

CONCLUSION

Fasting or PPPG values cannot be used as efficient screening tools for GDM developing in the later months of pregnancy.

Effects of pregnancy on health: certain aspects of importance for women with cystic fibrosis

More women with cystic fibrosis (CF) now reach reproductive age and wish to become pregnant. Although women with CF have reduced fertility, many of them can become mothers. A pregnancy ought to be carefully planned since several studies have shown that pregnancy is well tolerated if good medical care is provided, and the CF woman is in a stable good condition. A short review of the implications of pregnancy for women with CF is presented. A suggested schedule for pregnant women with CF is given.

Successful pregnancy and delivery in a young woman with cystic fibrosis and gestational diabetes

We describe a 23-year-old Delta F508 homozygote cystic fibrosis primigravida. At the onset of gestation, she had mild to moderate pulmonary involvement, exocrine pancreatic insufficiency, focal biliary cirrhosis, satisfactory nutritional status and normal fasting and post-prandial glucose blood levels. At 29 weeks, she developed polyhydramnion and gestational diabetes. At 37 weeks, she was delivered of a live 2,980 g boy by caesarean section under epidural anaesthesia. Insulin was subsequently discontinued and her pulmonary function improved spontaneously. Neither maternal nor neonatal health problems were observed during the 3-month follow-up.

A population-based risk factor scoring will decrease unnecessary testing for the diagnosis of gestational diabetes mellitus

BACKGROUND

To determine the effectiveness of a population-based risk factor scoring to decrease unnecessary testing for the diagnosis of gestational diabetes mellitus (GDM).

METHODS

We formed a risk factor scoring over five, which questions maternal age, body mass index and first-degree relatives with a diagnosis of diabetes mellitus, a prior macrosomic fetus and adverse outcome during the previous pregnancies. All participants underwent a 50-g glucose challenge test (GCT) followed by a 100-g oral glucose tolerence test (OGTT). We opened the 50-g GCT envelope if the participant had a risk score > or = 1 and opened the 100-g OGTT envelope if the 50-g GCT value was > or = 7.2 mmol/l. After all patients delivered we also built other strategies and tested their detection rates.

RESULTS

Fourteen patients (3.3%) were diagnosed as having gestational diabetes mellitus via a 100-g OGTT. None of the patients with a score of zero had gestational diabetes mellitus. Logistic regression analysis revealed that an increase in the score by one caused a three times increase in gestational diabetes mellitus risk (OR = 3, CI = 1.9-5). Compared with the universal screening, our strategy to screen if the risk score was > or = 1, followed by a 50-g GCT with a 7.2-mmol/l cut-off value, decreased the number of women to be screened by 30% and diagnosed all cases with GDM. Screening the patients with a score > or = 2 would have decreased the number of women to be screened by 63%, still diagnosing 85% of cases with GDM. Also, risk factor-based screening strategies cause a 50% and 53% reduction in the number of OGTT applied, respectively.

CONCLUSION

A well integrated, population-based scoring will decrease the number of unnecessary testing but still diagnose 85-100% of GDM cases.

Long-term risk of malignant neoplasm associated with gestational glucose intolerance

BACKGROUND

Previous studies have demonstrated an association between diabetes mellitus and cancer risk. However to the author's knowledge, no data regarding the risk of cancer associated with subclinical impaired glucose tolerance have been published to date. An association between various types of cancer and any continuum of risk across the spectrum of glucose tolerance may be important in determining the nature of the association between diabetes mellitus and the risk of malignancy.

METHODS

The current study was conducted to examine the long-term risk of malignant neoplasms associated with maternal glucose intolerance. A 20-year follow-up study of a cohort of women who had previously taken part in a study in 1980 that investigated maternal glucose metabolism and fetal outcome was performed. Gestational glucose metabolism, smoking behavior, and weight and height measured at the time of index pregnancy, as well as weight, height, and smoking behavior assessed by questionnaire in 1999, were examined. The main endpoint of the study was hospital admission with a diagnosis of malignant neoplasm as ascertained by linkage data.

RESULTS

Thirty-four of the 753 women living in Grampian (4.5%) were admitted to the hospital with a diagnosis of malignant neoplasm; of these, 18 cases were malignant neoplasms of the breast. After adjustment for known risk factors, both malignant neoplasm and malignant neoplasm of the breast were found to be significantly associated with gestational glucose intolerance.

CONCLUSIONS

Subclinical glucose intolerance during pregnancy was found to be associated with a dose-related increase in the risk of malignant neoplasm, particularly malignant neoplasm of the breast.

Glucose screening test results in first and early third trimester of pregnancy: is there any correlation?

OBJECTIVE

This study aims to find correlation between glucose screening test (GST) results done in the first trimester and again in the early third trimester of pregnancy.

METHODS

Analysis of the records of 458 cases of pregnant women (non-diabetic in early pregnancy as detected by glucose screening test and glucose tolerance test) between 22 and 35 years of age with a body mass index of less than 25 kg/m2 was done. These women underwent GST in the first trimester (GST-1) and again in the early third trimester (GST-2). When the GST-2 was 140 mg% or above, a standard '3 hour glucose tolerance test' was done (GT TEST) with 100 g of glucose. The GST was done by measuring the plasma glucose level 1 hour after taking 50 g of glucose, irrespective of food intake.

RESULTS

A substantial correlation between the two groups of measurements was found. Based on the available data, a GST-1 value of 99 mg% or less was seldom associated with GST-2 value of 140 mg% or more (GT TEST was positive in none). It was observed that 100% of cases with GST-1 value of 140 mg% or more had GST-2 of 140 mg% or more. Out of those having GST-2 value of 140 mg% or more, 72% had GT TEST positive. In the intermediate group (i.e. those patients having GST-1 value of 100 mg%-139 mg%), 51.7% had GST-2 values of 140 mg% or more. Out of these 51.7% cases, only 23% cases turned out to be GT TEST positive. The correlation coefficients (CC) worked out to be 0.38 (substantial correlation for 0.20 < CC < 0.70).

CONCLUSION

From the observations stated above, it is concluded that for women with GST-1 of 99 mg% or less, a GST-2 is not necessary. For those having GST-1 of 140 mg% or more, a GT TEST is absolutely necessary instead of repeating the screening test again in the third trimester. But it is in the intermediate group (i.e. with GST-1 value of 100 mg%-139 mg%) where the glucose screening test should be repeated in the early third trimester and GT TEST as and when necessary.

A comparison of costs associated with screening for gestational diabetes with two-tiered and one-tiered testing protocols

OBJECTIVE

The Fourth International Workshop on Gestational Diabetes recently suggested that two techniques, a 2-tiered protocol and a 1-tiered protocol, to screen for gestational diabetes mellitus are acceptable alternatives. This study was undertaken to compare the direct costs and patient time expenditures associated with implementing both techniques.

STUDY DESIGN

A MEDLINE search was undertaken to determine the prevalence of positive and negative screening results. Direct costs of testing were estimated by determining the range of supply costs from manufacturers' catalogs and the labor costs by estimating the time required to perform each procedure and multiplying by the appropriate range of wages; these costs were then multiplied by the appropriate range of the number of procedures required to implement both protocols, and the totals were summed. Patient time expended was estimated by assigning test times of 1, 2, and 3 hours for the 50-g screening glucose challenge test, the 75-g oral glucose tolerance test, and the 100-g oral glucose tolerance test, respectively. If additional visits were required, 2 travel-time units were assigned each time a patient underwent a procedure. These units were multiplied by the range of patients undergoing various tests to implement the alternative protocols.

RESULTS

We identified low and high direct costs, test times, and travel units per patient screened by the 1- and 2-tiered testing protocols. Low and high direct costs were $3.46 and $7.88, respectively, for the 2-tiered protocol and $5.64 and $10.88, respectively, for the 1-tiered protocol (relative ratios, 1.63 for low direct costs in each protocol and 1.38 for high direct costs in each protocol). Low and high test times were 1.4 and 1.5 hours, respectively, for the 2-tiered protocol and 2.0 and 2.0 hours, respectively, for the 1-tiered protocol (relative ratios, 1.47 for low test times in each protocol and 1.32 for high test times in each protocol). Low and high travel units for the 2-tiered protocol were 0.2 and 0.3, respectively, when the glucose challenge test was given at the prenatal visit, and 2.2 and 2.3, respectively, when the test was not given at that time. Low and high travel units for the 1-tiered protocol were 8.3 and 5.8, respectively, when the glucose challenge test was given at the prenatal visit, and 0.89 and 0.85, respectively, when the test was not given at that time.

CONCLUSIONS

The 2-tiered protocol appears to be associated with lower direct implementation costs and less patient time expenditure than the 1-tiered scheme. The 1-tiered protocol is associated with slightly less travel time, but this is unlikely to offset the test time advantage of the 2-tiered protocol. Until further data regarding the relative clinical utility of the 2 protocols become available, these factors may be important for clinicians in deciding which screening format to follow.

Pregnancy in cystic fibrosis. Fetal and maternal outcome

OBJECTIVE

To assess the effect of pregnancy on pulmonary function and survival in women with cystic fibrosis (CF) and to assess the fetal outcome.

DESIGN

Cohort study. The data analyzed were collected from the Toronto CF database, chart review, and patient questionnaire.

SETTING

Tertiary-care center.

PATIENTS

All women with CF who, at the time of diagnosis or pregnancy, attended the Toronto Cystic Fibrosis Clinics between 1961 and 1998.

RESULTS

From 1963 to 1998, there were 92 pregnancies in 54 women. There were 11 miscarriages and 7 therapeutic abortions. Forty-nine women gave birth to 74 children. The mean follow-up time was 11 +/- 8 years. One patient was lost to follow-up shortly after delivery, and one was lost after 12 years. The overall mortality rate was 19% (9 of 48 patients). Absence of Burkholderia cepacia (p < 0.001), pancreatic sufficiency (p = 0.01), and prepregnancy FEV(1) > 50% predicted (p = 0.03) were associated with better survival rates. When adjusted for the same parameters, pregnancy did not affect survival compared to the entire adult female CF population. The decline in FEV(1) was comparable to that in the total CF population. Three women had diabetes mellitus, and seven developed gestational diabetes. There were six preterm infants and one neonatal death. CF was diagnosed in two children.

CONCLUSIONS

The maternal and fetal outcome is good for most women with CF. Risk factors for mortality are similar to those for the nonpregnant CF population. Pregnancies should be planned so that there is opportunity for counseling and optimization of the medical condition. Good communication between the CF team and the obstetrician is important.

Jelly beans as an alternative to a fifty-gram glucose beverage for gestational diabetes screening

OBJECTIVE

This study tested the hypothesis that a standardized dose of jelly beans could be used as an alternative sugar source to the 50-g glucose beverage to screen for gestational diabetes mellitus.

STUDY DESIGN

One hundred sixty pregnant women at 24 to 28 weeks' gestation were recruited for a prospective study to compare 2 sugar sources for serum glucose response, side effects, preference, and ability to detect gestational diabetes mellitus. Patients were randomly assigned to consume 50-g glucose beverage or 28 jelly beans (50 g simple carbohydrate). Serum glucose values were determined 1 hour later. The test was later repeated with the other sugar source. Finally, a 100-g 3-hour oral glucose tolerance test was performed. Participants completed a questionnaire recording subjective outcome variables. American Diabetes Association criteria were used to interpret all test results.

RESULTS

Among 136 participants completing the study no significant differences were found between 1-hour serum glucose values (116.5 +/- 27 mg/dL with 50-g glucose beverage, 116.9 +/- 23.6 mg/dL with jelly beans; P =.84), frequency of discrepant results (P =.47), sensitivity, specificity, or predictive value. Jelly beans yielded fewer side effects (38% with 50-g glucose beverage, 20% with jelly beans; P <.001) and were preferred by 76% of participants (P <.001). Five cases (3.7% incidence) of gestational diabetes mellitus were diagnosed, 3 with 50-g glucose beverage alone, 1 with jelly beans alone, and 1 with both sugar sources.

CONCLUSIONS

Jelly beans may be used as an alternative to the 50-g glucose beverage as a sugar source for gestational diabetes mellitus screening. The 2 sources provoke similar serum glucose responses. Patients report fewer side effects after a jelly bean challenge than after a 50-g glucose beverage challenge.

Sequelae of unrecognized gestational diabetes

OBJECTIVE

Prior studies have suggested that macrosomia is the only morbid condition associated with gestational diabetes and that this association is the result of confounding by maternal obesity rather than a result of gestational diabetes itself. We sought to determine whether unrecognized gestational diabetes is an independent predictor of macrosomia and other perinatal morbid conditions after controlling for confounding variables.

STUDY DESIGN

A retrospective analysis of 472 consecutive cases of gestational diabetes diagnosed between 24 and 30 weeks' gestation was undertaken including 16 prospectively identified but clinically unrecognized cases, 297 cases treated with diet alone, and 76 treated with diet plus insulin. Unrecognized cases were matched to 64 nondiabetic controls for race, age, body mass index, parity, pregnancy weight gain, and gestational age at delivery.

RESULTS

In the unrecognized gestational diabetes group versus the nondiabetic control versus gestational diabetes diet groups rates of large for gestational age infants (44% vs 5% vs 9%, p < 0.0005), macrosomia (44% vs 8% vs 15%, p < 0.01), shoulder dystocia (19% vs 3% vs 3%, p < 0.05), and birth trauma (25% vs 0% vs 0.3%, p < 0.001) were all significantly increased. These differences remained significant after controlling for maternal age, race, parity, body mass index, pregnancy weight gain, and gestational age at delivery.

CONCLUSIONS

This study suggests that unrecognized gestational diabetes increases risks of large for gestational age infants, macrosomia, shoulder dystocia, and birth trauma independent of maternal obesity and other confounding variables. Clinical recognition and dietary control of gestational diabetes are associated with a reduction in these perinatal morbid conditions.

Pregnant women with impaired tolerance to an oral glucose load in the afternoon: evidence suggesting that they behave metabolically as patients with gestational diabetes

OBJECTIVE

In previous studies we observed the existence of a circadian variation of the blood glucose response to oral glucose in pregnant women with higher values at 4 PM. Some women with increased risk of diabetes with normal oral glucose tolerance tests at 8 AM also had values above maximum normal levels at 4 PM. The aim of this trial was to determine the clinical significance of this impaired tolerance in the afternoon.

STUDY DESIGN

Seventy-seven pregnant women with normal risk of diabetes (65 of normal weight and 12 overweight), 75 with increased risk of diabetes (26 overweight), and 12 patients with gestational diabetes were incorporated in the study. All women underwent two oral glucose tolerance tests (1.5 gm/kg) at 31 to 32 weeks' gestation at 8 AM and 4 PM with a 1-week interval. At 33 weeks' gestation a whole-day blood glucose profile was performed with usual food intake; samples were withdrawn before each meal and at 30, 60, and 120 minutes after each meal. The weight of the newborns was recorded.

RESULTS

(1) Results of oral glucose tolerance tests confirmed a circadian variation of the response in all groups; (2) 37 women with increased risk of diabetes had higher values after oral glucose tolerance testing than the normal threshold at 4 PM but not at 8 AM; (3) among women with normal risk of diabetes all values were within the normal range despite the circadian variation; (4) blood glucose levels during whole-day profiles were normal in women with normal risk of diabetes and with increased risk of diabetes with normal oral glucose tolerance testing at 4 PM, whereas all women with increased risk of diabetes and impaired tolerance in the afternoon showed hyperglycemic episodes; (5) the percentage of newborns with high weight (>90th percentile) among women with increased risk of diabetes and abnormal oral glucose tolerance tests at 4 PM was similar to the percentage found in women with gestational diabetes and much higher than the one observed in women with normal oral glucose tolerance tests in the afternoon.

CONCLUSIONS

The impairment of the response to oral glucose tolerance testing seen in some patients with increased risk of diabetes at 4 PM but not at 8 AM seems of clinical significance in view of the abnormal whole-day blood glucose profile these women had and the weights of the newborns.