1359-P: Neck Circumference: A Useful Tool for the Diagnosis of Gestational Diabetes and Risk of Adverse Outcomes in Overweight Pregnancy

Introduction: Few studies addressed the role of neck circumference (NC) as a risk factor during overweight pregnancy.

Objective: To evaluate the association of NC with GDM and adverse outcomes in overweight and obese women.

Methods: This longitudinal study included 132 (BMI>25kg/m²) pregnant women. Standardized questionnaire and biochemical/physical evaluation were performed when they were admitted at GDM outpatient clinic (2018-2019): during the 1^st to 3^rd trimester (without and with DMG according to the IADPSG criteria). Fifth-five women were evaluated regarding hypertension in pregnancy, type of delivery and neonatal complications (death, intensive care unit admission and hypoglycemia). ANOVA, Chi-square test and logistic regression were performed.

Results: Women with (n=61) and without (n=71) GDM had similar mean(SD) pre-gestational BMI [30.3(4.0)vs29.4(3.5)Kg/m²,p=0.16], familiar history of diabetes, physical activity, schooling, lipid profile, TSH levels and blood pressure. Women with GDM were older [32(6)vs28(6)yrs,p<0.001] and had greater NC [36.0(2.7)vs34.5(1.8)cm,p<0.001] than those without GDM. NC was similar in women with GDM diagnosed in first or third trimester [p=0.4] and was correlated with FPG [r0.29,p=0.01] and systolic [r0.28,p=0.001] and diastolic [r0.25,p=0.004] blood pressure. In logistic regression analysis, NC was associated with GDM [OR1.25,95%CI1.03to1.52] adjusted for age, physical activity, schooling and familiar history of diabetes. In ROC analysis, the area under the curve was 0.655 and the cut-off value of 34.5cm had 0.70 of sensitivity and 0.51 of specificity for GDM. Women who had NC≥34.5 vs. <34.5cm had higher frequencies of hypertension [32.3vs4.2%,p=0.01] and C-section [58.1vs29.2%,p=0.03] but not neonatal complications [45.2vs25.0%,p=0.12].

Conclusions: In a group of overweight or obese pregnant women the NC can be a useful tool for identifying GDM and obstetric adverse outcomes.