A comparative study of the different diagnostic criteria of gestational diabetes mellitus and its incidence

Background

High prevalence of diabetes and genetic predisposition to metabolic syndrome among Indians places Indian women at risk to develop gestational diabetes mellitus (GDM) and its complications. Literature defines multiple criteria for GDM. This prospective study compares available diagnostic criteria for GDM in Indian women and their correlation with perinatal morbidity.

Method

Nine hundred and forty-eight consecutive voluntary nondiabetic pregnant women were recruited for the study. Seven hundred and twenty-three of these (mean age 23.45 years; 75.7% < 25 years) who reported for the follow-up were screened for GDM at 24–28 weeks gestation by American College of Obstetrics and Gynaecology (ACOG) guidelines and World Health Organization (WHO) criteria. Glycated haemoglobin (HbA_1c) and fasting and two-hours postglucose plasma insulin levels were also analysed. Pregnancy outcome was known for 291 of these. Concordance of risk factors and perinatal complications was analysed with respect to GDM.

Results

Prevalence of GDM at 24–28 weeks gestation was found to be 4.8% by WHO criteria, 6.36% by Carpenter and Coustan's criteria, and 3.5% by O'Sullivan's criteria. Prevalence was marginally higher in women of higher age, having past history of abortion or family history of diabetes mellitus (DM) (P > 0.05). None of these women had HbA_1c > 6%. Relative risk of abnormal delivery (pregnancy outcome) was 1.93, 1.39, and 1.17 in women with GDM by O'Sullivan's, WHO, and Carpenter's criteria, respectively (P > 0.05). Abnormal deliveries were marginally higher in women with high postglucose load insulin levels. Mean weight of the newborns was essentially the same in GDM and nonGDM women by any of the criteria. One-hour and two-hours postglucose values were more sensitive in diagnosing GDM by O'Sullivan's criteria while fasting plasma glucose value had the poorest specificity with 2.5% of nonGDM women having values above the cut-off. Modifications of these criteria did not im-prove their predictive value for abnormal delivery over that of O'Sullivan's criteria.

Conclusion

Prevalence of GDM and abnormal delivery in women < 35 years of age is low. Therefore, global screening for GDM may not be very useful in women < 25 years of age unless family history of DM or past history of abortion is present. Existing evidence is inadequate to justify the switchover from O'Sullivan's criteria for diagnosis of GDM.     

High frequency oscillation and exogenous surfactant in the treatment of neonatal respiratory distress syndrome

Surfactant therapy has become widely used in neonates suffering from respiratory distress syndrome. High frequency oscillation has been shown to be efficient and safe in animal models, but somewhat less convincing in human neonates. An overview is given of the experimental and clinical data assessing the combination of these two techniques. Personal preliminary data are briefly presented.     

Precision of genotyping of Epstein-Barr virus by polymerase chain reaction using three gene loci (EBNA-2, EBNA-3C, and EBER): predominance of type A virus associated with Hodgkin's disease [published erratum appears in Blood 1993 Oct 1;82(7):2268]

To precisely determine the genotype of Epstein-Barr virus (EBV) in Hodgkin's disease (HD), we simultaneously analyzed three divergent gene loci (EBNA-2, EBNA-3C, and EBER) that distinguish type A and B viruses. The primers designed to amplify these three gene loci encompass either type-specific deletion sequences (EBNA-2 and EBNA-3C) or type-specific point mutations (EBER) that identify the virus strain based on the sizes of the polymerase chain reaction (PCR)-amplified products or the mobility shifts in single-strand conformation polymorphism analysis. The locations of point mutations were identified by direct sequencing of the PCR-amplified DNA. We analyzed 15 EBV-infected cell lines and found a good correlation between EBNA-2 and EBNA-3C typing results. In contrast, approximately 33% of the cell lines analyzed maintained type A sequences in EBNA-2 and EBNA-3C genes while carrying type B sequences in the EBER region. Data obtained from analysis of cell lines served as a reference for studying HD samples. EBV DNA was detected in about 70% of HD. Among the EBV-positive samples, 56% were associated with type A virus, 13% with type B, and 31% with dual viral sequences. Thus, type A virus is predominant in HD. Based on the histology, the frequencies of EBV positivity were 83%, 71%, and 33% for mixed cellularity, nodular sclerosis, and lymphocyte predominance, respectively. The detection of high frequency of both type A and B sequences in HD may provide a lead in investigating the role of dual viral infection in EBV pathogenesis.     

Identification, chromosomal mapping and tissue-specific expression of hREV3 encoding a putative human DNA polymerase zeta

The Saccharomyces cerevisiae REV3 gene encodes the catalytic subunit of a non-essential DNA polymerase zeta, which is required for mutagenesis. The rev3 mutants significantly reduce both spontaneous and DNA damage- induced mutation rates. We have identified human cDNA clones from two different libraries whose deduced amino acid sequences bear remarkable homology to the yeast Rev3, and named this gene hREV3. The hREV3 gene was mapped to chromosome 1p32-33 by fluorescence in situ hybridization. The hREV3 encodes an mRNA of >10 kb, and its expression varies in different tissues and appears to be elevated in some but not all of the tumor cell lines we have examined. In light of recent reports of a putative mouse REV3, these results indicate that mammalian cells may also contain a mutagenic pathway which aids in cell survival at the cost of increased mutation.