Apelin, Visfatin, Omentin and Resistin are adipocytokines derived from human adipose tissue as well as placental tissue and have been shown to be potential mediators of insulin resistance. In each pregnancy, a physiological Insulin resistance syndrome occurs to ensure that the fetus is sufficiently supplied with glucose. Due to their impact on glucose transport mechanisms adipocytokines play an important role for the development of insulin resistance.

Gestational diabetes mellitus (GDM) is one of the most common pregnancy - associated diseases with a prevalence of 5-10% of all pregnancies and its prevalence is increasing. It is associated with severe hazards to both mother and fetus such as macrosomia, plexus palsy, premature delivery and intrauterine death. Furthermore, up to 50% of women with GDM develop Type 2 Diabetes Mellitus (DM2) within the following ten years after pregnancy. GDM seems to be a potent risk factor for the development of DM2 in later life by sharing a number of epidemiological, physiological and genetic characteristics with DM2. Therefore, alterations in adipocytokine levels in women with GDM, if present, may resemble those observed with DM2.

Furthermore, the exact pathogenesis of GDM is not completely understood, however, increased insulin resistance is a well demonstrated mechanism.

Adipocytokines are known to alter insulin resistance through several mechanisms described in the literature. The investigators therefore expect a possible relationship between the above described adipocytokines and gestational diabetes mellitus.

Results of the HAPO-Study have shown a significant association between fetal outcome and mean blood glucose levels in women suffering from GDM. The HAPO Study group supposed a possible relationship between GDM and fetal insulin levels and used C-Peptide to quantify fetal hyperinsulinemia.

A recent study suggests that not only hyperglycemia but also altered maternal lipid metabolism may constitute a risk factor for macrosomia in GDM.

In summary, the investigators aim to illuminate a possible association between the adipocytokines Apelin, Omentin, Resistin and Visfatin, lipid metabolism and gestational diabetes mellitus.

Inclusion Criteria:

• Age above 18 years
• Informed consent
• Diagnosed gestational diabetes mellitus

Exclusion Criteria:

• Preexisting diabetes mellitus
• Any kind of immunodeficiency
• HIV, HCV, HBV
• Immunomodulating drugs (IF-Gamma, etc.)
• Cancer, chronic diseases

150 pregnant women with diagnosed gestational diabetes mellitus (Study group) and 150 pregnant women with normal oral glucose tolerance test (OGTT).