INTRODUCTION
Gestational diabetes mellitus (GDM) is defined as diabetes that is
diagnosed in the second or third trimester of pregnancy and not overt
prior to gestation (1). Over the past decade, the prevalence of GDM has
been on the rise (2). In 2013, International Diabetes Federation (IDF)
conducted a comprehensive survey based on the data from 47
epidemiological studies in 34 countries and regions around the world.
The global prevalence of hyperglycemia in pregnant women (20-49 years)
was 16.9%, and that of GDM was 14.2% for the same group; about 21.4
million live births showed signs related to maternal hyperglycemia (3).
The incidence of GDM varies with countries, and all show an upward
trend.
GDM causes adverse events both in women and children , such as maternal
type 2 diabetes and obesity in children (4, 5). Previous epidemiological
studies have found that GDM may increase the risk of childhood allergic
diseases, including asthma and atopic dermatitis (6, 7). Current
population-based research results are inconsistent. Delayed pneumocyte
differentiation and lung maturation were observed in the offspring in
rodent models of diabetes during pregnancy (8-11). The possible
mechanism for their pathogenesis is that phosphatidylglycerol production
may be inhibited in gestational diabetes, resulting in reduced
surfactants and increased susceptibility to respiratory distress
syndrome, which may also explain the increased risk of persistent
wheezing in human infants born to women with GDM (12).
Food allergy, wheezing, asthma and eczema are the most common allergic
disorders in children (13). Four endpoints were set in the present
study: asthma, atopic dermatitis, food allergy and wheezing. To date,
their association with GDM has not been systematically reviewed, and the
results of existing studies on the association are inconsistent. Thus,
we conducted a meta-analysis to evaluate the findings of previous
epidemiological studies.