Skin tag and acanthosis nigricans: do they have a predictive value for gestational diabetes mellitus?

Gestational diabetes mellitus (GDM) is a metabolic condition that can cause severe fetal and maternal morbidity. Early diagnosis and treatment of GDM can significantly prevent maternal and perinatal morbidity.

To investigate and compare the prevalence of gestational diabetes mellitus in pregnant women with skin tag (ST) and/or acanthosis nigricans (AN) and a control group.

This cross-sectional study was conducted at Adana Numune Educational and Research Hospital, Seyhan Practice Center, Dermatology and Obstetrics Clinics between March, 2006 and July, 2008. All 249 pregnant women without risk factors for GDM examined dermatologically in terms of AN and ST in the first antenatal visit. A 50 g glucose screening test and, if test positive, 100 g oral glucose tolerance test was performed between theirs 24 and 28 weeks of pregnancy. GDM was diagnosed according to American Diabetes Association (ADA) criteria. AN and ST prevalence were compared in women with GDM and without GDM.

35.8% of the pregnant women with AN had GDM, while the same ratio was 9.2% for the women without AN. The probability of pregnant women with AN having GDM is 5.5 (95%CI: 2.6-11.6) times more than the pregnant women without AN. Among the pregnant women with both ST and AN, 40.0% of them had GDM, while the same ratio was 12.3% for the women free of both ST and AN. In this instance, the difference between the ratios was found statistically significant (p=0.001). Based on the results, the probability of pregnant women with both ST and AN having GDM is 4.8 (95%CI: 1.9-11.7) times more than the pregnant women without ST and AN.

AN or AN with ST may be a risk factor for GDM. If this supported with large case-control study, early screening for GDM to prevent serious complications of disease should be done in pregnant women with AN.