The epidemiology and prediction of gestational diabetes mellitus
Creators: name: Makgoba, Mahlatse
Publisher: name: Imperial College London
Year: 2014

description: Objectives To examine the relationship between particular traditional risk factors and their effect on the development of gestational diabetes mellitus (GDM) and birthweight (Part 1) as well as to assess first trimester maternal biochemical predictors of development of GDM (Part 2). Methods Part 1. A retrospective study of prospectively collected data from fifteen maternity units in North West London between 1988-2000- the St Mary‘s Maternity Information System (SMMIS) dataset. The dataset was modified to include only those who were nulliparous (thus ensuring that only one pregnancy per woman was included) and excluding women with pre-existing diabetes (thus studying only women who either did or didn‘t develop gestational diabetes). Birthweight z-scores were calculated. Part 2. A nested case-control study using first-trimester (11+0 to 13+6 weeks of gestation) samples. that were obtained as part of a large prospective observational on-going study aimed at identifying first-trimester predictors of adverse pregnancy outcomes. Maternal levels of lipids (cholesterol, low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL), non-fasting triglycerides, C- reactive protein (CRP), γ-glutamyl transferase (γ - GT), adiponectin, E-selectin, tissue plasminogen activator (t-PA) and vitamin D (25(OH)D) were measured. Statistical Package for the Social Sciences (SPSS) Version 17.0 and R (version 2.11.0) was used for statistical analysis. Results Part 1. There was a strong association between advancing maternal age and increasing body mass index (BMI) on the development of GDM (p&lt;0.01 for both). This varied within each racial group and was more pronounced in Black African and South Asian groups. Using White European women with a BMI of 18.5-24.9 as a reference group, Black African and South Asian pregnant women had higher Odds Ratios (ORs) for GDM development within all BMI categories compared to the reference group. Maternal BMI was positively associated with birthweight z-scores within all racial groups (p&lt;0.001 for all) irrespective of glycaemic status but its effect was much greater in women with GDM. The difference in birthweight z-scores between GDM and non-GDM women varied according to racial group and was much higher in non-white racial groups and at high rather than at low BMIs. Part 2. Simple maternal demographic and clinical characteristics obtained at the first antenatal visit provide a good prediction of GDM. Low levels of HDL and high levels of t-PA are independent predictors of GDM. (p=0.001 and p&lt;0.001 respectively). First trimester maternal serum 25(OH)D levels are not associated with the development of GDM. Conclusions Maternal age and BMI interact with racial group in relation to the development of GDM. Both factors are important in the development of GDM, particularly so in Black African and South Asian women. GDM strongly accentuates the effect of BMI on birthweight, especially within non-white populations. First trimester prediction of GDM can be enhanced by the measurement of specific maternal biomarkers.