Poster Australasian Diabetes in Pregnancy Annual Scientific Meeting 2013

OUTCOMES OF WOMEN DIAGNOSED WITH GESTATIONAL DIABETES MELLITUS BEFORE 20 WEEKS GESTATION  (#119)

Tang Wong 1 2 , Jeff Flack 1 2 , Glynis Ross 1
  1. Department of Diabetes and Endocrinology, Bankstown-Lidcombe Hospital, Sydney, NSW, Australia
  2. University of NSW, Sydney, Australia

Background: ADIPS guidelines suggest an early oGTT in women at high risk for GDM(1). A previous study by Hawkins et al. demonstrated that women with an early diagnosis of GDM had an increased risk for LGA(2).

Aims: To compare outcomes of women diagnosed before and after 20 weeks gestation in a large GDM cohort in South-Western Sydney.

Methods: Retrospective analysis of prospectively collected data from our GDM database (1993-2012). Selected women, diagnosed by ADIPS criteria(3), had delivery outcome data and had attended a post-partum oGTT with concomitant HbA1c collection. Post-partum glycaemic status was classified according to oGTT results, (not HbA1c), with IFG being FBGL>6.1mmol/L. Data were compared by t-test or Chi-squared test. Fisher-Freeman-Halton exact test was used to detect differences in ethnicity. Statistical significance was p<0.05.

Results: There were 1879 women with available data, 244 diagnosed <20 weeks gestation (<20WkDx) and 1635 after 20 weeks (>20WkDx). There were no significant differences in ethnicity, but <20WkDx women were older, with higher gravida, parity, self-reported pre-pregnancy BMI and more risk factors for GDM. In the <20WkDx women there was significantly more insulin use, but no significant increase in early delivery (<37weeks) or caesarean delivery, with non-statistically significant differences in SGA and LGA. Of note was the significant increase in any abnormality of glucose tolerance on 6-8 weeks post-partum glucose tolerance test (oGTT), especially Type2DM (see Table - mean±SD or percent).

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Conclusions: Although women with a diagnosis of GDM before 20 weeks gestation had worse baseline metabolic characteristics compared to those diagnosed after 20 weeks, the rates of adverse neonatal outcomes were similar. In this cohort, these women had less weight gain and non-significantly less LGA than those diagnosed after 20 weeks. Therefore early diagnosis of GDM, coupled with early intervention, had favourable perinatal and fetal outcomes. However these women require heightened surveillance post-partum due to an elevated risk of persisting dysglycaemia. 

Acknowledgment: All of the Diabetes Educators who have collected data and maintained the database.

  1. Nankervis A, McIntyre HD, Moses R, Ross GP, Callaway L, Porter C, Jeffries W, Boorman C, De Vries B for the Australasian Diabetes in Pregnancy Society. Australasian Diabetes In Pregnancy Society (ADIPS). Consensus Guidelines for the Testing and Diagnosis of Gestational Diabetes Mellitus in Australia. 14th February 2013.
  2. Hawkins JS, Lo JY, Case BM, McIntire DD, Leveno KJ. Diet-treated gestational diabetes mellitus: comparison of early vs routine diagnosis. Am J Obstet Gynecol 2008;198:287.
  3. Hoffman L, Nolan C, Wilson JD, Oats JJN, Simmons D. Gestational diabetes mellitus – management guidelines. The Australasian Diabetes in Pregnancy Society. Med J Aust 1998;169:93–97.