Early gestational diabetes mellitus (GDM) is associated with worse pregnancy outcomes compared with GDM diagnosed at 24-28 weeks gestation despite early treatment

Abstract

Background: Gestational diabetes mellitus (GDM) is associated+ with adverse pregnancy outcomes compared with women with normal glucose tolerance in pregnancy. The WHO recommends screening at 24-28 weeks gestation for GDM. Women who are diagnosed before 24-28 weeks gestation have a longer intervention period which may impact positively on pregnancy outcomes.

Aim: This study aimed to examine pregnancy outcomes of women with GDM diagnosed <24 weeks gestation compared with those diagnosed at 24-28 weeks in a large Irish cohort.

Methods: A retrospective cohort study of 1471 pregnancies in women with GDM diagnosed using IADPSG criteria between September 2012 and April 2016 was conducted. At GDM diagnosis, women were classified as early GDM <24 weeks or standard GDM 24-28 weeks gestation.

Results: Women with early GDM had a significantly greater risk of pregnancy-induced hypertension (12.4% vs. 5.3%; P < 0.05), post-partum haemorrhage (8.7% vs. 2.4%; P < 0.05) and post-partum glucose abnormalities (32% vs. 15.6%; P < 0.05). Their offspring had a greater risk of pre-maturity (10.9% vs. 6.6%; P < 0.05), stillbirth (1.4% vs. 0.5%; P < 0.05), large for gestational age (19.1% vs. 13.4% P < 0.05) and need neonatal intensive care (30.7% vs. 22.1%; P < 0.05) compared with offspring of women with standard GDM. Rates of C-section and pre-maturity were still higher in the early GDM group when the two groups where compared based on their post-natal OGTT.

Conclusion: Early GDM women and their offspring are at greater risk of an adverse pregnancy outcome compared with those diagnosed at 24-28 weeks. In view of the abnormal post-natal glucose findings, early GDM may reflect a more advanced state in diabetes pathogenesis.