Introduction
Type 2 diabetes mellitus (T2DM)
is a pandemic with increasing prevalence worldwide.1
Gestational diabetes mellitus (GDM) is one of the most common conditions
in pregnancy, with short- and long-term complications both for the
mother and offspring 1,2. The risk factors for GDM are
similar to those of T2DM and with increasing obesity and sedentary
lifestyles, the prevalence of GDM, as well as T2DM, among
reproductive-aged women, is growing globally 2.
Moreover, GDM is considered an established risk factor for T2DM. It is
estimated that up to 70% of women with GDM will develop T2DM within
22–28 years after pregnancy 2.
Prediabetes is defined outside of pregnancy as fasting plasma glucose
(FPG) levels between 100 and 125 mg/dl or impaired glucose tolerance
(2-hour glucose levels between 140-199mg/dl in 75 grams glucose
tolerance test), or A1C 5.7-6.4% 1,3. During
pregnancy, the definition of prediabetes is controversial.
Most international guidelines on GDM diagnosis suggest screening for GDM
preferably at 24-28 gestational weeks and early screening only for women
with diabetes risk factors2. Thus, 1st-trimester
evaluation of FPG level is not routinely performed for all pregnant
women, and management of 1st-trimester FPG levels that are within the
levels equivalent to the diagnosis of prediabetes outside of pregnancy
is controversial. Recently, the International Association of the
Diabetes and Pregnancy Study Groups (IADPSG) defined early GDM as an
early pregnancy FPG level between 92 and 125 mg/dl4,5. Early GDM was found to be associated in some
studies with adverse perinatal outcomes 6 with no
clear benefit of treatment 6,7. Furthermore, unlike
GDM, the impact of early GDM as a predictor for future T2DM was not well
established.
In Israel, the Ministry of Health guidelines recommend early screening
for overt diabetes for all parturients using FPG levels, evaluated in
the 1st trimester. Therefore, in this study, we aimed
to evaluate the prediction of T2DM by 1st trimester FPG levels and
compare it to GDM in a large cohort of women with up to 5 years of
follow-up after pregnancy.