GENERAL ORAL GLUCOSE TOLERANCE TEST DURING PREGNANCY, AN OPPORTUNITY FOR IMPROVED PREGNANCY OUTCOME AND IMPROVED FUTURE HEALTH

Abstract: Gestational diabetes mellitus (GDM) is associated with a risk of adverse pregnancy
outcome and is a predictor of subsequent diabetes. The aims of this work were to
describe a reliable routine to diagnose abnormal glucose tolerance during pregnancy,
to investigate women’s opinions of the specialist care provided, to determine the
prevalence of diabetes one year after giving birth, and to elucidate the effect of
abnormal glucose tolerance on pregnancy outcome and on the women’s future health.
Routines for a general decentralised oral glucose tolerance test (OGTT) at antenatal
clinics, with high quality and high compliance of the patients are described. Perinatal
outcome was determined and compared for the years 1995-1999 and 2000-2003, and
in two geographical areas with different screening routines (OGTT and random
glucose measurements, RGM). The routine use of OGTTs identified twice as many
cases of GDM as RGM. Those not identified with RGM were as affected.
The women’s opinions of the extended care programme were analysed using a
questionnaire. The results showed great satisfaction with the care provided, especially
the sound knowledge of the staff. However, a desire for better preparation before the
OGTT, better information flow and more information on normal pregnancy was
expressed.
Women delivered in 2003-2005 who had undergone an OGTT during pregnancy
participated in a follow-up study 1-2 years after delivery. Different cut-off limits were
used for 2-h capillary plasma glucose concentrations at OGTT during pregnancy.
GDM >10.0 mmol/L, gestational impaired glucose tolerance (GIGT) 8.6-9.9
mmol/L, and a control group <8.6 mmol/L. At follow-up, 11% (n=160) of the GDM
group, 4% (n=309) of the GIGT group and none of the controls had diabetes. When
diagnosed with GIGT a retest was offered. Two-thirds of the women with diabetes
after GIGT were found in the group diagnosed as having GDM after retest during
pregnancy. Adverse pregnancy outcome was observed in both the GDM and GIGT
groups compared with the controls.
Women with previous GDM were more than 3 times as likely as a group to consume
health care resources in a year after delivery (odds ratio 3.5, 95% CI 2.5-5.0), leading
to an average 50% higher cost (p<0.001). Annual excess cost was apparent up to 7
years after childbirth (p<0.01).
A general routine OGTT during pregnancy identifies women with GDM, providing
the opportunity to improve the pregnancy outcome and to make lifestyle changes that
can improve the future health of both mother and child.