Identification and Treatment of Women With Hyperglycaemia Diagnosed During Pregnancy Can Significantly Reduce Perinatal Mortality Rates

Abstract

Summup:We wished to determine whether gestational diabetes was associated with an increased perinatal mortality rate, and to investigate the cause for the observed increase in the incidence of gestational diabetes. We therefore reviewed the results of glucose tolerance tests and pregnancy outcome in 116,303 pregnancies, 1971-1994, at the Mercy Hospital for Women. The main outcome measurements were the presence or absence of gestational diabetes, and perinatal mortality. Over the entire period of the study, gestational diabetes was associated with an increased risk of perinatal mortality (Mantel-Haenszel adjusted odds ratio 1.53, 95% CI 1.13-2.06, p=0.0069). Women with gestational diabetes that was only diagnosed retrospectively had a higher perinatal mortality rate than their contemporaries with normal glucose tolerance (OR 2.31,95% CI 1.37-3.91, p=0.0025). Women in whom a glucose tolerance test was not performed continued to have a higher perinatal mortality rate than women who were tested (adjusted OR 2.21,95% CI 1.56-3.12, p<o.ooOOl). There has been an increase in the prevalence of gestational diabetes from 2.9% to 8.8%. Some of this is due to changes in population characteristics (increases in maternal age, obesity and proportion from South-East Asia), but there was still an independent increase over time. We conclude that identification and treatment of women with gestational diabetes can reduce perinatal mortality rates. Similarly to diabetes mellitus in the total population, the prevalence of gestational diabetes has increased over time.

Gestational diabetes in Victoria in 1996: incidence, risk factors and outcomes

“…Previous estimates of GDM incidence worldwide vary from 1% to 10%. Previous Australian reports may have over‐estimated the incidence 5 . ‐ 8 Our population‐based study showed that the incidence was higher in women attending the larger hospitals or living in the metropolitan regions — sites where earlier studies have been conducted.…”

“…In Australia, previous attempts to determine the true incidence have been based on surveys of prenatal clinics consisting of hospital patients and/or private patients, 5 ‐ 8 but these are subject to bias due to referral patterns, local population variations and local clinical practice.…”

The extent of undiagnosed gestational diabetes mellitus in New South Wales

“…The NSW MDC annual publications from 1992 to 1994 show the gestational age of delivery and the perinatal mortality rate for all births at 32-36 weeks' gestation and for those at or after 37 weeks' gestation. For direct comparison with the data of Beischer et aI., 4 births and perinatal deaths in week 36 were estimated as one-fifth of the total of births and perinatal deaths, respectively, for the period 32-36 weeks' gestation and added to the data available for deliveries at or after 37 weeks' gestation.…”

Studies of Postnatal Diabetes Mellitus in Women Who Had Gestational Diabetes

“…We have reported elsewhere that the incidence of GD at the Mercy Hospital for Women has trebled in the 24 years from 1971 to 1994 from 2.9% to 8.8% (13). Because the figure was derived from tested pregnancies it might tend to be an overestimate because tested pregnancies were probably more likely to have a higher incidence of GD than the untested population.…”