Making the diagnosis of gestational diabetes mellitus

Investigation of diabetes-related molecular changes in embryo-endometrium crosstalk

The primary aim of this study was to explore the impact of diabetes on matrix metalloproteases and tissue inhibitors, crucial factors for successful implantation, and to elucidate the molecular mechanisms that undergo changes in the endometrium and the embryo during diabetic pregnancies. In this investigation, we established a streptozotocin-induced diabetic pregnant rat model. Microarray analysis followed by RT-PCR was utilized to identify gene regions exhibiting expression alterations. Subsequently, we assessed the effects of MMPs and tissue inhibitors using ELISA and immunohistochemistry techniques, in addition to analyzing changes at the genetic level. Diabetes led to the upregulation of MMP3, MMP9, and MMP20 on the 6.5th day of pregnancy, while causing the downregulation of MMP3, MMP9, and MMP11 on the 8.5th day of pregnancy. TIMP1 expression was downregulated on the 8.5th day compared to the control group. No statistically significant differences were observed between the groups regarding other TIMP expressions. KEGG pathway analysis revealed that diabetes induced alterations in the expression of genes associated with certain microRNAs, as well as signaling pathways such as cAMP, calcium, BMP, p53, MAPK, PI3K-Akt, Jak-STAT, Hippo, Wnt, and TNF. Additionally, gene ontology analysis unveiled changes in membrane structures, extracellular matrix, signaling pathways, ion binding, protein binding, cell adhesion molecule binding, and receptor-ligand activity. This study serves as a valuable guide for investigating the mechanisms responsible for complications in diabetic pregnancies. By revealing the early-stage effects of diabetes, it offers insight into the development of new diagnostic and treatment approaches, ultimately contributing to improved patient care.

Perinatal Outcomes in Obese Women with One Abnormal Value on 3-Hour Oral Glucose Tolerance Test

OBJECTIVE

This study aimed to determine if one abnormal value of four on the diagnostic 3-hour oral glucose tolerance test (OGTT) is associated with adverse perinatal outcomes in obese women.

STUDY DESIGN

This is a secondary analysis of a prospective study of nulliparous women in eight geographic regions. Women with body mass index <30 kg/m² and pregestational diabetes mellitus (GDM) were excluded. Four groups were compared: (1) normal 50-g 1-hour glucose screen, (2) elevated 1-hour glucose screen with normal 100-g 3-hour diagnostic OGTT, (3) elevated 1-hour glucose screen and one of four abnormal values on 3-hour OGTT, and (4) GDM. Using multivariable logistic regression adjusting for covariates, the women in the groups with dysglycemia were compared with those in the normal screen group for maternal and neonatal outcomes.

RESULTS

Among 1,713 obese women, 1,418 (82.8%) had a normal 1-hour glucose screen, 125 (7.3%) had a normal 3-hour diagnostic OGTT, 72 (4.2%) had one abnormal value on their diagnostic OGTT, and 98 (5.7%) were diagnosed with GDM. The one abnormal value group had increased risk of large for gestational age (LGA) neonates (adjusted odds ratio [aOR] = 2.24, 95% confidence interval [CI]: 1.31-3.82), cesarean delivery (aOR = 2.19, 95% CI: 1.34-3.58), and hypertensive disorders of pregnancy (aOR = 2.19, 95% CI: 1.32-3.63) compared with normal screens. The one abnormal value group also had an increased risk of preterm birth <37 weeks (aOR = 2.63, 95% CI: 1.43-4.84), neonatal respiratory support (aOR = 2.38, 95% CI: 1.23-4.60), and neonatal hyperbilirubinemia (aOR = 2.00, 95% CI: 1.08-3.71). There was no association between one abnormal value with shoulder dystocia and neonatal hypoglycemia.

CONCLUSION

For obese women, one abnormal value on the 3-hour OGTT confers increased perinatal adverse outcomes. These women should be studied further to determine if nutrition counseling and closer fetal monitoring improve outcomes even in the absence of a diagnosis of GDM.

KEY POINTS

· Study of obese women with one abnormal value on OGTT.. · Adverse maternal and neonatal outcomes were found, including more LGA neonates.. · Neonates were not at increased risk of hypoglycemia..

Sense making in complex health situations

Purpose

Using a sense making approach, the purpose of this paper is to examine the role that virtual health communities play as a source of informational and social support for pregnant diabetic women. The paper helps to understand how women suffering from a critical medical condition (i.e. diabetes during pregnancy and birth) manage a complex health situation.

Design/methodology/approach

The data sample consisted of 507 posts collected from a virtual health community for diabetic pregnant women. Data were analysed deductively looking for different expressions of normality and different types of health information about diabetes.

Findings

Content analysis revealed four themes that reflect the process that diabetic women go through from their attempts to conceive through pregnancy and birth. The findings show that for women dealing with a chronic illness such as diabetes, the breakdown of normal was the beginning of the pregnancy that prompted a new range of informational and emotional needs. The members of the community negotiated a socially constructed sense of normality and tried to empower other members with a new sense of normal by sharing information about their births. The findings also showed that members of the community disclosed personal health information to elicit medical information, advice and social support from other members.

Originality/value

The study highlighted the significance of sense-making processes in managing complex health situations and the value of virtual communities as sources of information and social support as to resolve discontinuities in the management of their illnesses.

Candy twists as an alternative to the glucola beverage in gestational diabetes mellitus screening

OBJECTIVE

Screening for gestational diabetes mellitus commonly uses an oral glucose challenge test with a 50-g glucola beverage and subsequent venous puncture. However, up to 30% of pregnant women report significant side-effects, and the beverage is costly. We hypothesized that equivalent glucose loads could be achieved from a popular candy twist (Twizzlers; The Hershey Company, Hershey, PA) and tested it as cost-effective, tolerable alternative with a test of equivalency.

STUDY DESIGN

The glucose equivalent of the 50-g glucola was calculated as 10 candy twists. We initially used a triple crossover design in nonpregnant patients whereby each subject served as her own control; this ensured the safety and equivalency of this load before using it among pregnant subjects. We then recruited pregnant women with an abnormal screening at 1 hour (glucose challenge test) in a double crossover design study. Subjects consumed 10 candy twists with a 1-hour venous blood glucose assessment. All subjects subsequently completed the confirmatory 3-hour glucose tolerance test. Sensitivity, specificity, positive predictive values, negative predictive values, false-referral rates, and detection rates were calculated.

RESULTS

At ≥130 mg/dL, the sensitivity (100%) was the same for candy twists and glucola. However, the false-referral rate (82% vs 90%), positive predictive value (18% vs 10%), and detection rate (18% vs 10%) were improved for candy twists when compared with the 50-g glucola beverage.

CONCLUSION

Our results indicate that strawberry-flavored candy twists are potentially an equally effective screening test, compared with the gold standard glucola beverage but lead to fewer false-positive screens and therefore could be a cost-effective alternative.

Cord blood nesfatin-1 and apelin-36 levels in gestational diabetes mellitus

To assess maternal serum and cord blood apelin-36 and nesfatin-1 concentrations in pregnant women with and without gestational diabetes mellitus (GDM). Thirty pregnant women with GDM and 30 gestational age matched healthy pregnant subjects participated to the study. Maternal serum and cord blood nesfatin-1 and apelin-36 levels were measured with ELISA, at the time of birth. The relationships between maternal serum and cord blood nesfatin-1 and apelin-36 levels, anthropometric and metabolic parameters were also assessed. Maternal serum apelin-36 levels were found higher (13.5 ± 8.3 vs. 9.6 ± 5.9 ng/ml, P = 0.001) and nesfatin-1 levels were found lower (5.5 ± 8.1 vs. 8.1 ± 23.9 ng/ml, P = 0.001) in patients with GDM compared with control pregnant women. However, the cord blood apelin-36 levels (8.8 ± 4.3 and 8.2 ± 1.9 ng/ml, P = 0.618) and nesfatin-1 levels (5.4 ± 4.0 and 6.2 ± 10.3 ng/ml, P = 0.688) were similar in the GDM and control groups, respectively. Maternal serum apelin-36 and nesfatin-1 levels correlated positively with their respective cord blood levels. Maternal serum and cord blood apelin-36 levels correlated negatively with the gestational age and birth weight. Similarly maternal serum and cord blood nesfatin-1 levels correlated negatively with the gestational age, but there was no correlation with the birth weight. We did not find a correlation between maternal serum apelin-36 and nesfatin-1 levels, maternal age, BMI, fasting glucose, fasting insulin, and HOMA-IR. Also cord blood apelin-36 and nesfatin-1 levels did not correlate with the maternal age, BMI, HOMA-IR, cord blood glucose, and cord blood insulin levels. Our results indicate that apelin-36 concentrations increase and nesfatin-1 concentrations decrease in maternal serum of women with GDM.

Glycohemoglobin A1c: A promising screening tool in gestational diabetes mellitus

CONTEXT:

Current screening tests for gestational diabetes mellitus (GDM) are inconvenient. Therefore, alternative screening tests for GDM are desirable. The use of glycohemoglobin A1c (HbA1c) in screening for GDM remains controversial.

AIM:

We undertook this study to evaluate the utility of HbA1c in screening for GDM.

SETTINGS AND DESIGN:

Retrospective study in a tertiary teaching hospital.

MATERIALS AND METHODS:

Laboratory records were reviewed to identify pregnant women who underwent both oral glucose tolerance test (OGTT) and HbA1c measurements over a 16-months period. The association of OGTT with HbA1c was evaluated.

STATISTICAL ANALYSIS USED:

Data were collected using SPSS software. Comparisons of the means and calculations of sensitivities were performed.

RESULTS:

Of 145 eligible patients, 124 had GDM and 21 patients did not, per OGTT. The percentages of patients with HbA1c values (reference range of 4.8%–6.0%) equal to or above sequential cut-point values of 5.0%, 5.5%, 6.0%, 6.5% and 7.0% (i.e., sensitivity values) were 100%, 98.4%, 87.1%, 62.9% and 39.5%, respectively. The mean HbA1c of the patients with GDM was 6.9 + 0.8% compared to 6.4 + 0.6% for those without GDM (P< 0.006). At an arbitrary cut-off value of 6.0% (the upper limit of normal), HbA1c would have picked up 87.1% of patients with GDM.

CONCLUSIONS:

This study suggests that HbA1c is a reasonably sensitive screening measure of GDM in this high-risk population. Acknowledging limitations resulting from the study design, further prospective studies are warranted to verify this conclusion, and to evaluate the specificity of HbA1c as a screening test for GDM.

Maternal serum and cord blood preptin levels in gestational diabetes mellitus

OBJECTIVE

To assess preptin concentrations in pregnant women with and without gestational diabetes mellitus (GDM) and in the cord blood of their fetuses.

STUDY DESIGN

In all, 31 pregnant women with GDM and 31 gestational age-matched healthy pregnant subjects participated. Maternal serum and cord blood preptin levels were measured with ELISA. The relationships between maternal serum and cord blood preptin levels, anthropometric and metabolic parameters were also assessed.

RESULT

Maternal serum and cord blood preptin levels were found higher in patients with GDM compared with control pregnant women. Preptin concentration in maternal serum was positively correlated with maternal age, fasting insulin levels, 1-h blood glucose after glucose load and cord preptin concentrations at birth. However, relationships between maternal and/or cord serum preptin and fetal growth parameters at birth were not detected.

CONCLUSION

Our results indicate that preptin concentrations increase in maternal serum of women with GDM. Preptin levels may provide a novel approach to identify women with GDM.

Antenatal oral glucose-tolerance test values and pregnancy outcomes

Objective

The aim of the present study was to explore the impact of individual blood glucose values (n = 4; i.e. fasting and 1, 2 and 3 h following oral glucose administration) obtained during antenatal oral glucose-tolerance testing, together with two different sets of criteria used for diagnosis of gestational diabetes mellitus (GDM) — Carpenter and Coustan Criteria (CCC) and National Diabetes Data Group (NDDG) criteria — in predicting pregnancy outcomes and maternal insulin need.

Setting

Al Ain Hospital, United Arab Emirates.

Method

This observational uncontrolled cohort study gained its study subjects from a randomised, controlled, longitudinal, prospective clinical trial performed at Al Ain Hospital, Al Ain, United Arab Emirates. The eligible population was made up of all women (n = 720) who participated in an early screening programme for GDM. Those who had a positive oral glucose-tolerance test (OGTT) based on CCC were included in the study (n = 165). All recruited women with GDM were followed from time of recruitment to 6months postpartum. The sources of information used were maternal and neonatal medical records and laboratory findings for women both antenatally and postnatally.

Results

The maternal and neonatal outcomes indicated that the number of abnormally elevated antenatal OGTT values obtained during the diagnosis of GDM was significantly correlated with development of a number of pregnancy complications. Data analysis also indicated that the number of abnormal diagnostic antenatal OGTT values using CCC was significantly correlated with development of postpartum diabetes mellitus (P = 0.044) within 6months of delivery. The number of abnormal OGTT values significantly contributed to insulin need during the index pregnancy (P &lt; 0.05). The CCC approach was more sensitive than the NDDG methodology for predicting the onset of GDM and a number of the associated complications.

Conclusions

The study highlighted the importance of abnormal values for antenatal OGTT in identifying the need for insulin management in women with GDM.

Comparison of the American Diabetes Association and World Health Organization criteria for gestational diabetes mellitus and the outcomes of pregnancy

Two to five percent of pregnancies are complicated by diabetes, of which 90% are classified as gestational diabetes mellitus.The aims and objectives of this study were to analyse the screening and diagnostic procedure for gestational diabetes mellitus (GDM) recommended by American Diabetes Association (ADA) in comparison with the World Health Organization (WHO) criteria and to study the outcome of GDM diagnosed by both the criteria. This prospective study was carried out in the Department of Obstetrics and Gynaecology, JIPMER between August 2006 and July 2008. Three-hundred-and-fifty antenatal cases of gestational age ≥24 weeks attending the outpatient department, with any one of the risk factors for GDM, were included in the study. A seventy-five gram oral glucose tolerance test (GTT) was performed on each subject. Results were interpreted using both ADA and WHO criteria. Antenatal complications of GDM, mode of delivery, intrapartum or postnatal maternal and neonatal complications in cases diagnosed with GDM by either criterion were noted. The data collected were analysed using the SPSS software program. The prevalence of GDM was 4% by ADA criteria versus 19.4% by WHO criteria. The diagnostic pick-up rate was approximately five times more with WHO than with ADA criteria. In total, 43% (ADA) and 29% (WHO) of GDM cases had antenatal complications. Seventy-four percent of mothers with macrosomic babies were identified by WHO criteria whereas only 26% of mothers with macrosomic babies were diagnosed by ADA criteria. ADA criteria identify more severe cases of GDM but mild cases diagnosed by WHO are missed. The GTT by WHO criteria was abnormal in a greater percentage of women with adverse outcomes especially macrosomia, than the GTT using ADA criteria.

Effect of different degrees of glucose intolerance on maternal and perinatal outcomes

OBJECTIVE

To evaluate the effect of markedly elevated 50-g glucose loading test (GLT) (>or=200 mg/dL) and equivocal 100-g GLT (one abnormal value) results on maternal and perinatal outcomes.

METHODS

Retrospective analysis of 2029 singleton pregnancies screened for gestational diabetes mellitus (GDM). Maternal and perinatal outcomes in five different groups with different degrees of glucose intolerance were compared. First group consisted of patients with normal 50-g test, second group was formed by patients with abnormal 50-g glucose test but a normal 100-g test. Third group included patients with one abnormal value after 100-g test. Patients in the fourth group were diagnosed to have GDM after an abnormal 100-g test. Patients in the fifth group had a value >or=200 mg/dL after 50-g test and were diagnosed to have GDM.

RESULTS

Macrosomia and large for gestational age incidence were highest in the group with one elevated glucose tolerance test (GTT) value. Hospitalisation rates, hypoglycemia, hyperbilirubinemia and polycythemia were more common in neonates born to mothers with one elevated GTT value and to mothers with a GLT > 200 mg/dL.

CONCLUSION

Adverse maternal and perinatal outcomes in patients with one elevated GTT value and in patients with a GLT value > 200 mg/dL warrant close glucose monitoring and treatment in these groups even in the absence of a diagnostic abnormal GTT.

Glycemic levels with glucose loading test during pregnancy and its association with maternal and perinatal outcomes

OBJECTIVE

To evaluate the association between glycemic levels with glucose loading test during pregnancy and maternal and perinatal outcomes.

METHODS

Retrospective analysis of 2059 singleton pregnancies screened for gestational diabetes mellitus at Gazi University Faculty of Medicine, Department of Obstetrics and Gynecology between January 2004 and December 2006 was conducted. Sensitivity and specificity of the 50 g glucose loading test was calculated for different cut-off values in our population. Maternal and perinatal outcomes in different groups with different results after screening test were compared.

RESULTS

An increase in cut-off value from 140 to 145 mg/dl seems to be associated with a significant increase in specificity along with a tolerable decrease in sensitivity. A cut-off value of 147.5 mg/dl is associated with a higher specificity and a slightly lower sensitivity. However, the cut-off value 150 mg/dl seems to be associated with a significant decrease in sensitivity. As for the upper limit, a cut-off value of 180 mg/dl is associated with a 90% specificity and a cut-off value of 200 mg/dl is associated with a 99% specificity. A 100% specificity could be reached only after a cut-off value of 221 mg/dl. A GLT value of 180 mg/dl or higher was found to be associated with poor maternal and fetal outcomes, regardless of the result obtained after the diagnostic test.

CONCLUSION

Results obtained after 50 g GLT should be evaluated separately for each patient and the diagnostic test which is time-consuming, uncomfortable and expensive can be omitted up to a cut-off value of 147.5 mg/dl, especially for those patients with no risk factors. Besides, a GLT value of 180 mg/dl or higher proves the diagnostic test unnecessary as these patients are associated with unfavorable perinatal and fetal outcomes.

Outcomes of pregnancies affected by impaired glucose tolerance

OBJECTIVE

Gestational diabetes mellitus (GDM) is associated with an increase in both maternal and neonatal morbidity. There remains uncertainty, however, about the diagnostic criteria for GDM. We compared pregnancy outcomes across three groups of women, with the aim of establishing a threshold for diagnosis of GDM at our institution.

METHODS

Women with a glucose tolerance test (GTT) were identified on the hospital's pathology database. Those women with a singleton pregnancy, in whom a GTT had demonstrated a fasting value </=5.5mmol/L, 2-h blood sugar >/=7.8mmol/L and who confined </=34 weeks gestation were eligible for inclusion. Outcomes were collected from the medical records and obstetric database. These women were managed with either diet modification, regular endocrinologist review and standard antenatal care if the GTT met ADA criteria (n=265, TREATED), or standard antenatal care alone if the GTT did not fulfil ADA criteria (n=213, UNTREATED). A third group comprised of women with normal GTT who received identical treatment to the untreated group (n=197, COMPARISON). Statistical analysis was conducted with chi(2) and ANOVA.

RESULTS

In women with untreated GDM, there was significantly more macrosomia, shoulder dystocia, and preeclampsia, compared with the comparison group. These rates were similar between the treated and comparison groups. There were no significant differences in induction of labour, caesarean section rates, or gestational age at delivery between the groups.

CONCLUSION

Untreated GDM is associated with larger babies and more birth trauma. We recommend the diagnosis of GDM be made with fasting glucose >/=5.5mmol/L and/or 2h >/=7.8mmol/L on 75g GTT.

Elevated second trimester serum homocysteine levels in women with gestational diabetes mellitus

OBJECTIVE

Our aim was to investigate the association between total serum homocysteine, vitamin B12 and folate levels in pregnant women with gestational diabetes mellitus (GDM), glucose intolerance and compare them with those of glucose tolerant pregnant women.

MATERIALS AND METHODS

Serum homocysteine, vitamin B12 and serum folate levels were prospectively measured in a total of 223 pregnant women who were grouped according to their status of glucose tolerance as gestational diabetes (abnormal 1-h and 3-h glucose tolerance test; n = 30), glucose intolerant (abnormal 1-h, but normal 3-h glucose tolerance test; n = 46) or normal controls (normal 1-h glucose test; n = 147).

RESULTS

Mean serum homocysteine concentration of women in gestational diabetes, glucose intolerants and normal controls at 24-28 weeks of gestation was 9.0 +/- 3.1, 8.1 +/- 2.5 and 7.4 +/- 1.6 micromol/l, respectively. The only statistically difference in homocysteine levels was observed between women with gestational diabetes and normal controls (P < 0.01). However, no difference was observed for vitamin B12 and folate levels.

CONCLUSION

Second trimester serum homocysteine concentrations are higher among women with GDM, as compared to normal controls.

Utility of casual postprandial glucose levels in type 2 diabetes management

OBJECTIVE

Because readily available glycemic indicators are needed to guide clinical decision-making for intensification of diabetes therapy, our goals were to define the relationship between casual postprandial plasma glucose (cPPG) levels and HbA(1c) in patients with type 2 diabetes and to determine the predictive characteristics of a convenient glucose cutoff.

RESEARCH DESIGN AND METHODS

We examined the relationship between cPPG levels (1-4 h post meal) and HbA(1c) levels in 1,827 unique patients who had both determinations during a single office visit.

RESULTS

The population studied was predominantly African American and middle-aged, with average cPPG of 201 mg/dl and HbA(1c) of 8.4%. The prevalence of HbA(1c) > or = 7.0% was 67% and HbA(1c) >6.5% was 77%. Overall, cPPG and HbA(1c) were linearly correlated (r = 0.63, P < 0.001). The correlation between cPPG and HbA(1c) was strongest in patients treated with diet alone (n = 348, r = 0.75, P < 0.001) and weaker but still highly significant for patients treated with oral agents (n = 610, r = 0.64, P < 0.001) or insulin (n = 869, r = 0.56, P < 0.001). A cutoff cPPG >150 mg/dl predicted an HbA(1c) level > or = 7.0% in the whole group, with a sensitivity of 78%, a specificity of 62%, and an 80% positive predictive value. The same cPPG cutoff of 150 mg/dl predicted an HbA(1c) level >6.5%, with a sensitivity of 74%, a specificity of 66%, and an 88% positive predictive value.

CONCLUSIONS

When rapid-turnaround HbA(1c) determinations are not available, a single cPPG level >150 mg/dl may be used during a clinic visit to identify most inadequately controlled patients and allow timely intensification of therapy.

The number of abnormal plasma glucose values in the oral glucose tolerance test and the feto-maternal outcome of pregnancy

OBJECTIVE

With respect to the feto-maternal outcome of pregnancy both appropriate screening and treatment of gestational diabetes mellitus (GDM) remain a matter of debate. Furthermore, the importance of only one abnormal glucose value at the glucose tolerance test (GTT) is still discussed, including the term "gestational impaired glucose tolerance" with normal fasting but an increased 2h postprandial glucose value.

STUDY DESIGN

We have evaluated the feto-maternal outcome of pregnancy in 152 women with abnormal glucose values during the oral 100g GTT. The data were analysed with respect to the number of abnormal GTT values and compared to age- and body mass index (BMI)-matched control groups including 304 women with normal GTT values.

RESULTS

A positive family history of diabetes was found in 24.4% of the GDM women and in 16.4% of the control group. In 45.9% of the women with abnormal GTT values glucose target levels could be obtained by dietary management, 54.1% required additional insulin therapy. Insulin therapy was administered in 32.8% of the women with one abnormal GTT value, in 65.0% of the women with two abnormal values and in 83.3% of the women with three abnormal values. Compared to the age- and BMI-matched control group the percentage of women with hypertension was increased in women with one, two and three abnormal GTT values. The percentage of LGA and macrosomic infants was significantly increased only in women with three abnormal GTT values. Women with one, two or three abnormal GTT values revealed an increased percentage of caesarean section compared to the control group.

CONCLUSIONS

Our results show that women with three abnormal GTT values are at an overall increased risk with respect to the feto-maternal outcome of pregnancy. Compared to the control group also women with only one abnormal GTT value revealed an increased risk indicating a need for further control and therapy.

The 75-gram glucose load in pregnancy: relation between glucose levels and anthropometric characteristics of infants born to women with normal glucose metabolism

OBJECTIVE

To investigate, in pregnant women without gestational diabetes mellitus (GDM), the relation among obstetric/demographic characteristics; fasting, 1-h, and 2-h plasma glucose values resulting from a 75-g glucose load; and the risk of abnormal neonatal anthropometric features and then to verify the presence of a threshold glucose value for a 75-g glucose load above which there is an increased risk for abnormal neonatal anthropometric characteristics.

RESEARCH DESIGN AND METHODS

The study group consisted of 829 Caucasian pregnant women with singleton pregnancy who had no history of pregestational diabetes or GDM, who were tested for GDM with a 75-g, 2-h glucose load, used as a glucose challenge test, in two periods of pregnancy (early, 16-20 weeks; late, 26-30 weeks), and who did not meet the criteria for a GDM diagnosis. In the newborns, the following abnormal anthropometric characteristics were considered as outcome measures: cranial/thoracic circumference (CC/TC) ratio </=10th percentile for gestational age (GA), ponderal index (birth weight/length(3) x 100) >/=90th percentile for GA, and macrosomia (birth weight >/=90th percentile for GA), on the basis of growth standard development for our population. For the first part of the objective, logistic regression models were used to identify 75-g glucose load values as well as obstetric and demographic variables as markers for abnormal neonatal anthropometric characteristics. For the second part, the receiver operating characteristic (ROC) curve was performed for the 75-g glucose load values to determine the plasma glucose threshold value that yielded the highest combined sensitivity and specificity for the prediction of abnormal neonatal anthropometric characteristics.

RESULTS

In both early and late periods, maternal age >35 years was a predictor of neonatal CC/TC ratio </=10th percentile and macrosomia, with fasting 75-g glucose load values being independent predictors of neonatal CC/TC ratio </=10th percentile. In both periods, 1-h values gave a strong association with all abnormal neonatal anthropometric characteristics chosen as outcome measures, with maternal age >35 years being an independent predictor for macrosomia. The 2-h, 75-g glucose load values were significantly associated in both periods with neonatal CC/TC ratio </=10th percentile and ponderal index >/=90th percentile, whereas maternal age >35 years was an independent predictor of both neonatal CC/TC ratio </=10th percentile and macrosomia. In the ROC curves for the prediction of neonatal CC/TC ratio </=10th percentile for GA in both early and late periods of pregnancy, inflection points were identified for a 1-h, 75-g glucose load threshold value of 150 mg/dl in the early period and 160 mg/dl in the late period.

CONCLUSIONS

This study documented a significant association, seen even in the early period of pregnancy, between 1-h, 75-g glucose load values and abnormal neonatal anthropometric features, and provided evidence of a threshold relation between 75-g glucose load results and clinical outcome. Our results would therefore suggest the possibility of using a 75-g, 1-h oral glucose load as a single test for the diagnosis of GDM, adopting a threshold value of 150 mg/dl at 16-20 weeks and 160 mg/dl at 26-30 weeks.

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.

Evidence-based diabetes screening during pregnancy

The concept of gestational diabetes was described more than a half century ago and has been studied extensively for more than 30 years. Available data indicate that the prevalence is highly variable, probably reflecting underlying risk factors. In addition, gestational diabetes is not a specific disease, but rather an abnormal laboratory value. Criteria for diagnosis are variable, and there is little agreement about who should be screened, if screening should be selective or universal, or how screening should be performed. Moreover, the most commonly used criteria in the United States differ from the European and World Health Organization standard criteria. This article describes the background for diabetes testing, current evidence for testing and diagnosis in pregnant women, "risks" of diagnosis, and various screening procedures and protocols, using data-based evidence when available. Midwifery practice recommendations are also made, including examination of risk factors as clinical decisions are made about guidelines.