A pilot community-based screening program for gestational diabetes

Perinatal mortality in diabetic pregnancy

Perinatal mortality rate (PMR) is one of the most important perinatal health indicators. PMR in diabetic pregnancies varies throughout the world and is higher than the background PMR. The prevalence of pregestational diabetes is increasing and is associated with an elevated risk of congenital malformations, macrosomia, preeclampsia, and preterm delivery. The incidence of PMR in preexisting diabetes mellitus ranges considerably, with congenital abnormalities and preterm labor the main factors contributing to the higher PMR. Women with gestational diabetes mellitus or impaired glucose tolerance are a mixed group that may have low to a high PMR, especially if they require insulin in their pregnancy. All the known diabetic women should plan their pregnancies and optimize glycemic control periconceptually and throughout pregnancy, as this reduces the frequency of congenital abnormalities, obstetric complications, and perinatal mortality.

Postpartum oral glucose tolerance tests in mothers of macarosomic infants: inadequacy of current antenatal test criteria in detecting prediabetic state

OBJECTIVE

To assess the presence of subtle carbohydrate metabolism abnormalities in otherwise healthy mothers who have given macrosomic birth by utilizing postpartum oral glucose tolerance test (PPOGTT).

STUDY DESIGN

Prospective controlled study enrolled gestational diabetic women (GDM, n=10), mothers with macrosomic infants (MwMIs, n=62) and controls (n=50).

RESULTS

Receiver operating characteristic (ROC) curve analysis revealed that incremental 1-h+2-h PPOGTT value >111 mg/dl had a sensitivity of 80% and specificity of 78% in predicting antecedent diabetes. PPOGTT results were positive in 53.2% of MwMIs and 28% of controls (P<0.01). Maternal low-density lipoprotein and triglyceride levels, 50 gram glucose challenge test (50 g GCT) values and neonatal weight were the significant predictors of PPOGTT results. ROC analyses suggested that threshold of 50 g GCT should be lowered in order to better predict subjects with both macrosomia and positive PPOGTT.

CONCLUSION

PPOGTT may identify a subset of women with macrosomic infants who have metabolic alterations of a prediabetic state. The discrepancies between antenatal and postpartum tests may reflect the need for redefinition of currently utilized criteria in screening and diagnosis of GDM.

A randomized controlled trial of strict glycemic control and tertiary level obstetric care versus routine obstetric care in the management of gestational diabetes: a pilot study

OBJECTIVES

The purpose of this study was to determine whether strict maternal glycemic control for the treatment of gestational diabetes lessened the risk of fetal macrosomia, birth trauma, neonatal hypoglycemia, and operative delivery. The aim of the pilot study was to prepare for a multicenter trial by assessing patient acceptance of the study, by determining realistic accrual rates, and by detecting any major adverse outcomes in the control group that received routine obstetric care.

STUDY DESIGN

The study was a prospective randomized controlled trial comparing fetal-neonatal and maternal outcomes in 300 women with gestational diabetes. Women randomized to the treatment arm were managed by strict glycemic control and tertiary level obstetric care, and women in the control arm received routine obstetric care.

RESULTS

Three hundred women with gestational diabetes mellitus were studied. There was no difference in maternal age, weight, or length of gestation between groups. The treatment mean birth weight was 3437 +/- 575 gm compared with 3544 +/- 601 gm in the control group, a difference of 107 gm (not significant). Macrosomia rates were similar. There was no birth trauma in either group. The frequency of neonatal hypoglycemia and other metabolic complications was the same. The mode of delivery also showed similar patterns. The treatment group had significantly lower preprandial and postprandial glucose levels by 32 weeks' gestation, which continued to term.

CONCLUSION

This pilot study suggests that intensive treatment of gestational diabetes mellitus may have little effect on birth weight, birth trauma, operative delivery, or neonatal metabolic disorders. It has demonstrated the safety of proceeding to a multicenter trial of sufficient sample size to confirm these findings.

Maternal hyperphenylalaninaemia as a cause of microcephaly and mental retardation

We attempted to evaluate the role of maternal hyperphenylalaninaemia (HPA) as an isolated cause of mental retardation and microcephaly in children. This transversal study observed the plasma phenylalanine from mothers of 161 children with mental retardation and/or microcephaly of unknown origin. In this sample, we found two women with previously undiagnosed HPA, a frequency (2/161) higher than expected for our general population (1:12 500) (p < 0.001). We concluded that the plasma phenylalanine levels should be determined during preconceptional evaluation of every woman of reproductive age that already has had a child affected either by mental retardation or microcephaly of unknown cause. It is particularly significant where women currently having their pregnancies have not been screened for phenylketonuria as newborns, as happens in most developing countries.

Plasma glucose and pre-eclampsia

OBJECTIVE

To determine whether there is a relationship between plasma glucose level in a glucose screening test and the occurrence of pre-eclampsia in non-diabetic pregnant women.

METHODS

All pregnant non-diabetic women attending the antenatal clinic at the Aga Khan University Medical Center were screened with a 75 g-2 h glucose challenge test (GCT). From 1988-90, a data base of 1316 cases was compiled for use in this study. Of these, 67 had to be excluded because of one or more abnormal levels in the 75 g-3 h oral glucose tolerance test (GTT) that required treatment to maintain euglycemia. Among the remaining patients (n = 1249) who had no evidence of glucose intolerance and were included in the analysis, there were 42 cases of pre-eclampsia. The association between pre-eclampsia and plasma glucose level in the GCT was evaluated using logistic regression analysis that adjusted for effects of age and gravidity.

RESULTS

The odds of having pre-eclampsia were increased by 20% (95% confidence interval 0%-44%) per mmol/l rise in plasma glucose level in the GCT. The same statistic for age was 9% (95% confidence interval 2%-17%), and for primigravidity it was 210% (95% confidence interval 55%-517%). There was no significant interaction between these variables.

CONCLUSIONS

Minor degrees of glucose intolerance, age and primigravidity are associated with a higher occurrence of pre-eclampsia in non-diabetic pregnant women.

Relationship of fetal macrosomia to a 75g glucose challenge test in nondiabetic pregnant women

We determined in nondiabetic women, the relationship of plasma glucose values obtained 2 hours after a 75 g oral glucose challenge test (GCT) at 16-20 weeks' gestation, with the incidence of macrosomia in term deliveries (37-41 weeks' gestation). From 1988-1990, in a systematic screening programme data collected prospectively from 1,331 women were analysed retrospectively. Women with gestational diabetes or impaired glucose tolerance (n = 53) were excluded. The rest (n = 1,278) had no evidence of glucose intolerance including 1,215 women with normal plasma glucose by GCT (< 7.8 mmol/L 2 hours after 75 g oral glucose load) and 63 women with abnormal GCT but not abnormal value at a glucose tolerance test. The GCT values were divided into 5 groups: Group A (< 4.5 mmol/L), B (4.5-5.5 mmol/L), C (5.6-6.6 mmol/L), D (6.7-7.7 mmol/L) and E (> 7.8 mmol/L). The variables studied were age, parity, gestational age at delivery and incidence of macrosomia. Using > 4 kg birth-weight as the definition of macrosomia, the incidence increased from 1.2% to 9.5% with increasing plasma glucose values in the GCT from Group A (> 4.5 mmol/L) to E (> 7.8 mmol/L). Similar trends of increasing incidences from 7.2% to 15.8% and 2.9% to 9.5% were noted when 90th and 95th birth-weight percentiles, respectively were used as definitions of macrosomia. The test of linear trend in this association was significant (p < 0.01). These results were not influenced by parity or gestational age at delivery.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of 1 hour 50 g oral glucose load screening test for gestational diabetes mellitus compared to 3 hour oral glucose tolerance test in high risk pregnant women

A prospective study for detecting gestational diabetes mellitus was undertaken to evaluate the use of one hour plasma glucose level after 50 g glucose loading test (1-hr GLT) as compared to the traditional 3-hours 100 g oral glucose tolerance test (3-hr OGTT) in 396 high risk cases. Each patient, had 1-hr GLT and 3-hr OGTT performed in a separate week. Forty-two cases (10.6%) who had abnormal 3-hr OGTT were classified as gestational diabetes (GDM). One hundred and sixty cases (40.4%) had an abnormal 1-hr GLT (plasma glucose level > or = 140 mg/dl). Thirty-six of these 160 cases (22.5%) had an abnormal 3-hr OGTT. In 236 women (59.6%) that had normal 1-hr GLT (plasma glucose level < 140 mg/dl) only 6 cases (2.5%) had an abnormal 3-hr OGTT. If 1-hr plasma glucose level > or = 150 mg/dl was used as the cutoff point, 110 cases (27.8%) were found to have abnormal 1-hr GLT, and 35 of these 110 cases (31.8%) had an abnormal 3-hr OGTT. Seven of 286 women (2.4%) that had normal 1-hr GLT (plasma glucose level < 150 mg/dl) had an abnormal 3-hr OGTT. The sensitivity and specificity of the 1-hr GLT when abnormal 3-hr OGTT was used as gold standard for detecting GDM were 85.7% and 65% respectively (BS > or = 140 mg/dl). Whereas the sensitivity and specificity were 83.3% and 78.8% respectively when plasma glucose level > 150 mg/dl was used as the cut point.(ABSTRACT TRUNCATED AT 250 WORDS)

Screening and diagnosis of gestational diabetes

This chapter discusses the evidence for the existence of an entity called 'gestational diabetes', suggesting that it can be understood in terms of risk to the pregnancy and/or risk to the mother. Various diagnostic criteria used in various parts of the world are described, and a rationale for using pregnancy-specific criteria is put forth. Universal screening approaches are also characterized. Barriers to the universal adoption of a single screening scheme and set of diagnostic criteria are outlined.

Gestational diabetes mellitus among African-American women

Gestational diabetes mellitus (GDM) is associated with increased risk of poor outcomes for the pregnancy. It is a strong risk factor for subsequent diabetes. The epidemiology of GDM in African-American women is not well known. It has not been demonstrated that their risk factors are similar in character and weight to those among White women. There is considerable multicollinearity among GDM risk factors such as age, parity, obesity, hypertension, and family history of diabetes, and this needs to be sorted out. This review is based on the results of a nested case-control study to evaluate the frequency of, and the relationships of the known risk factors with, the onset of GDM among African-American women. All cases of GDM within a cohort of women seen at any of the county health department clinics in Jefferson County, Alabama from 1981 to 1987 were identified. The cohort represents approximately 63% of all African-American pregnancies in the county during the period. With few exceptions (5.1% based on fasting plasma glucose greater than or equal to 120 mg/dl), potential GDM cases (7.1%) were selected on the basis of a 2 h post 100 g carbohydrate meal screening plasma glucose measure at their second prenatal visit and again at 28-32 weeks greater than or equal to 115 mg/dl and diagnosed on the basis of the results of an oral glucose tolerance test (OGTT) using the criteria of O'Sullivan and Mahan. Women with any prior history of diabetes (even in pregnancy), 1.6%, were excluded. The frequency of the new diagnosis of GDM among African-American women in this pregnancy in the cohort was 2.5% of pregnancies and 3.4% of women, which is similar to the values reported in the other studies. Controls were selected from women with negative screening tests who delivered after a GDM subject. The results reported in this paper reflect 358 cases (86% of all eligible GDM cases identified) and 273 controls. Cases were significantly older (28.3 vs. 21.7 years), of higher gravidity (2.7 vs. 1.9), more obese (76.7 vs. 61.7 kg), gained weight more rapidly (0.34 vs. 0.28 kg/week), had more hypertension in this pregnancy (28.2 vs. 2.6%), and there was a higher proportion with a family history of diabetes (41.3 vs. 16.5%) (p less than 0.001 for all comparisons). Because there were significant correlations among the risk factors in both cases and controls, multivariable logistic regression analyses were performed.(ABSTRACT TRUNCATED AT 400 WORDS)

The influence of demographic and phenotypic heterogeneity on the prevalence of gestational diabetes mellitus

In order to explore the influence of demographic and phenotypic characteristics on the prevalence of gestational diabetes mellitus (GDM), data were analyzed from 3744 consecutive patients who underwent universal screening with a 50 g glucose load at 24-28 weeks gestational age. Those with a 1-h plasma glucose greater than or equal to 130 mg/dl underwent a 3-h, 100-g oral glucose tolerance test following dietary preparation. The population was 39.1% White, 37.7% Black, 19.8% Hispanic and 3.4% Oriental/other. The overall prevalence of GDM was 3.5 cases/100. Significant inter-racial differences in maternal age and prepregnant percent ideal body weight (PIBW) were observed, with White patients being older and leaner than Blacks and Hispanics. By multiple logistic regression, Black and Hispanic race, maternal age and PIBW were found to have significant independent effects on the prevalence of GDM. Controlling for age and PIBW, the adjusted relative risk of GDM was significantly higher in Black (1.81, 95% CI 1.13-2.89) and Hispanic (2.45, 95% CI 1.48-4.04) patients compared to White. We conclude that demographic and phenotypic characteristics of populations need to be taken into consideration in future studies of prevalence of GDM, perinatal implications and therapeutic approaches to the disease.

Glucose tolerance in pregnancy: ethnic variation and influence of body habitus

Little is known about ethnic differences in glucose tolerance during pregnancy. In this study we examined 3366 Hispanic, Chinese, black, and non-Hispanic white women in a universal screening program for gestational diabetes mellitus. After maternal age and body mass index were controlled, Chinese women had a significantly higher serum glucose level 1 hour after 50 gm of oral glucose (134.8 +/- 1.2, mean +/- SE) than any of the remaining three groups. Black women had a significantly lower value (113.3 +/- 1.3, mean +/- SE) than either Chinese or Hispanic women (124.4 +/- 0.9, mean +/- SE). Results for Hispanic women and non-Hispanic white women (121.4 +/- 1.6, mean +/- SE) were not different. The screening glucose levels of Chinese women were substantially higher than other ethnic groups even when women with gestational diabetes were removed from the analysis, indicating that the observed differences were not solely due to a higher frequency of gestational diabetes among the Chinese. The incidence of gestational diabetes was significantly greater for Chinese (7.3%) and Hispanic (4.2%) women than for black (1.7%) and non-Hispanic white (1.6%) women. Among women who had a 3-hour glucose tolerance test, the area under the glucose curve was significantly associated with maternal age and body mass index. The demonstrated heterogeneity of glucose tolerance between ethnic groups may be of importance in determining the threshold for diabetic fetopathy, and it is possible that ethnicity-specific standards will need to be developed.

Diabetes in pregnancy: maternal and infant outcome

Previous studies have shown that diabetic women more commonly have complications of pregnancy and adverse infant outcomes than do other women. However, most of the studies have not evaluated women with gestational diabetes separately. The purpose of this study was to evaluate pregnancy complications and infant morbidity and mortality among births to women with gestational diabetes and women with established diabetes. Birth certificate data from 1984 in Washington State linked with death certificate data provided information on complications of pregnancy and infant outcome for 422 gestational diabetics and 144 established diabetics. A comparison group of 856 non-diabetic women who delivered a child was selected at random. Both established and gestational diabetic women were more likely to be reported to develop pre-eclampsia (relative risk (RR) = 4.0 and 9.6). Established and gestational diabetic women were also at increased risk of delivery by Caesarean section (RR = 2.1 and 5.0). Infants of established diabetics had a higher risk of congenital anomalies (RR = 7.6) than infants of non-diabetics and were at increased risk of death in the first 4 weeks (RR = 7.9) and the first year of life (RR = 5.0). Gestational diabetics were more likely to have high birthweight babies (greater than 4000 g) (RR = 2.1) while established diabetics were more likely to have babies at either extreme of birthweight (greater than 4000 g, RR = 1.7; less than 2500 g, RR = 3.2). We conclude that both gestational and established diabetes are associated with important increases in risk of pregnancy complications and adverse infant outcomes.

Gestational diabetes and impaired glucose tolerance of pregnancy in Riyadh

A total of 1088 pregnant women was screened for abnormalities in glucose metabolism at the initial antenatal visit; those with specific risk factors were screened again after 28 weeks gestation. In 210 (19.3%) plasma glucose measured 2 h after a 75 g glucose load was greater than or equal to 7.8 mmol/l (140 mg/dl). Follow-up glucose tolerance tests revealed an overall prevalence of abnormal tests of 10.3% (112 of 1088) according to the WHO criteria, of which 21 (1.9%) were diagnosed as gestational diabetes, and 91 (8.4%) as impaired glucose tolerance. This high prevalence was significantly related to age, parity and body mass index. Screening and diagnosis using criteria set by the WHO were found acceptable and are recommended to help resolve the international disagreement on diagnostic criteria of glucose metabolism abnormalities in pregnancy.

Gestational diabetes screening in a private, midwestern American population

This prospective investigation was undertaken to compare the value of routine versus selective diabetes screening in a group of predominantly middle-class, healthy, Caucasian pregnant women. Two thousand consecutively chosen persons were divided into two groups: those to undergo routine screening between 24 and 28 weeks' gestation and those to be tested selectively in the presence of standard risk factors. The two groups of patients were otherwise similar. The method of screening involved a 50 gm oral glucose challenge, followed by a 3-hour glucose test if necessary. The incidence of gestational onset diabetes in the selectively screened group (19/453, 4.2%) was twice that in the routinely screened group (21/1000, 2.1%). Evidence of glucose intolerance without a risk factor was found in only one case (1/1000, 0.1%) in the routinely screened group. This assessment of our clinical practice has allowed us to safely eliminate the need for diabetes screening in more than half of our private patients, which will reduce office time, patient inconvenience, and expense.

Screening for diabetes in pregnancy: is a random blood glucose enough?

It has been suggested that a single random blood glucose measurement, timed in relation to food, can be used to determine those women needing a formal oral glucose tolerance test for the detection of gestational diabetes. One hundred and ten pregnancies have been screened to compare the results of a formal oral glucose tolerance test with timed venous plasma glucose measurements taken throughout the day. At the suggested thresholds of 6.1 mmol/l (within 2 h of eating) and 5.6 mmol/l (at greater than 2 h of food), random blood glucose testing is specific and excludes most normal women. However, the sensitivity of the test is low, and the majority of those with impaired glucose tolerance would be missed. Random blood glucose measurement is not a sufficiently sensitive method for detecting gestational diabetes as presently defined.

Ten-year experience of insulin treatment in gestational diabetes

Between 1975-1984, 119 women with gestational diabetes (GDM) were treated with insulin in Uppsala, representing a mean yearly incidence of 4.5/1,000 pregnancies. Women with GDM were older and more obese than the general pregnant population. Insulin treatment was instituted during a 5-7 day stay in hospital. The mean total daily dose of insulin prepartum, when fasting blood glucose had been normalized, was 53 (SD +/- 25) units (34 +/- 15 units of rapid-acting and 20 +/- 11 units of medium-acting insulin), divided into two doses daily. Mean duration of treatment was 6.4 weeks. The perinatal mortality was 0.8%, compared with 7.4% in previous pregnancies in the same women. The perinatal morbidity was generally mild and included hypoglycaemia (10.9%), hyperbilirubinaemia requiring treatment (2.5%), shoulder dystocia (2.5%) and one case of mild respiratory distress syndrome. The rate of macrosomia was reduced in the present pregnancies compared with previous ones in the women with GDM, but not abolished completely, probably because of too short a duration of improved metabolic control. Spontaneous delivery was favoured and the rate of Caesarean section was 13.5%. Thus, treatment with high doses of insulin in an unselected group of women with GDM is feasible. Normal perinatal mortality, reduced macrosomia, and no gross perinatal morbidity was found in the infants. Though the extent to which insulin treatment per se contributed to the favourable outcome is difficult to assess, it is suggested that the case for a high level of ambition for metabolic normalization in GDM should be a subject of further study.

Criteria for screening tests for gestational diabetes

A 50 gm, 1-hour glucose screening test was given to 381 gravid women 25 years of age or older. All women with plasma glucose values greater than or equal to 130 mg/dl (119 mg/dl, whole blood) were given a 100 gm, 3-hour glucose tolerance test to diagnose gestational glucose intolerance using O'Sullivan's diagnostic criteria. On the basis of the distribution of screening test values, three diagnostic zones could be identified: a zone below 135 mg/dl plasma glucose, with less than 1% probability of diabetes; a zone above 182 mg/dl plasma glucose, with more than 95% probability of diabetes; and a central zone of uncertainty (135 to 182 mg/dl, plasma glucose), where further testing is required. These test results suggest that thresholds for further testing be lowered from 143 to 135 mg/dl of plasma glucose.

Clinical experience with a screening program for gestational diabetes

Screening for abnormal glucose metabolism was carried out in 2,077 pregnant women. Historical or clinical risk factors for gestational diabetes were present in 959 women (group 1). The remaining 1,118 patients composed group 2. A 50 gm oral glucose load and a 1-hour serum glucose determination with a threshold of 150 mg/dl were used as a glucose challenge screening test (GCT). Patients with an abnormal GCT underwent an oral glucose tolerance test (GTT). Group 1 patients underwent screening at the initial clinic visit or when the clinical risk factor was first recognized, with repeat screening at 28 to 32 weeks if the initial testing was normal. Group 2 patients were screened at 28 to 32 weeks. In group 1, 69 patients (7.2%) exhibited an abnormal GCT and 14 (1.5%) demonstrated an abnormal GTT. In group 2, 68 patients (6.1%) exhibited an abnormal GCT and 16 (1.4%) demonstrated an abnormal GTT. These incidences are not statistically different. The estimated costs per patient screened and per case of gestational diabetes detected were $4.75 and $328.96, respectively.