Poster Presentation Australasian Diabetes in Pregnancy Society Annual Scientific Meeting 2019

Oral glucose tolerance testing in pregnancy and impact on perinatal outcomes (#62)

Rebecca Olivo 1
  1. Obstetrics and Gynaecology, Caboolture Hospital, Caboolture, Queensland, Australia

Aims
It is well established that a diagnosis of gestational diabetes mellitus (GDM) carries an increased risk of adverse maternal and perinatal outcomes. A diagnosis of GDM is based entirely on a single step oral glucose tolerance test (OGTT) at 24-28 weeks gestational age. Glycaemic control is the mainstay of GDM management. This study aims to identify if there is a significant difference in the rate of both preterm birth (PTB) and foetal macrosomia in women treated as GDM compared to women with a normal OGTT result.

Methods
This is a retrospective cohort study including all women with a singleton pregnancy and a date of confinement between October 2018 and December 2018 at Caboolture Hospital. Maternal and neonatal data were collected from both perinatal data and medical records. Data were summarized by occurrence for all categoric variables. Pearson’s chi-square test was used for statistical analysis of GDM status and neonatal outcomes. P<0.05 was considered to be statistically significant. 

Results
A total of 412 women were identified in the study period, of which 121 (29.4%) had a diagnosis of GDM. No relationship was identified between GDM status and the rate of PTB or foetal macrosomia (p>0.05).

Conclusions
Babies born to GDM mothers did not have statistically significant rates of PTB and macrosomia when compared to babies of mothers with a normal OGTT result. This outcome may be attributed to early GDM management and good glycaemic control throughout pregnancy. A proportion of women with normal OGTT may have also had a poor diet throughout pregnancy, but we cannot control for this. This raises the question of whether or not all women should be actively managed as GDM, regardless of OGTT result. As such, the role of universal screening for GDM in pregnancy and the cost-effectiveness of OGTT merits further investigation.