Abstract

Gestational Diabetes Mellitus complicates 2-9% of pregnancies and is associated with obesity and hypertension. Accurate measurement of blood pressure requires the use of an arm cuff customised to the mid-arm circumference (MAC). A large cuff should be used for an MAC > 33.0cm.

The authors compared the Mid-Arm Circumference (MAC) between women attending our Diabetic and standard antenatal clinics. After the blood pressure was measured, the MAC was measured. The Body Mass Index (BMI) was calculated at the first antenatal visit.

In the standard clinic (n=101), the mean BMI was 25.1kg/m² and the mean MAC was 28.7cm. In the Diabetic Clinic (n=39), the mean BMI was 29.2kg/m² and the mean MAC was 31.5cm. The number of women with a MAC >33.0cm was 23% in the Diabetic Clinic compared with 12% in the standard clinic (p<0.001). In the BMI 30.0-34.9kg/m² category, 29.4% had a MAC>33.0cm while in the BMI >35.0kg/m² category, 92% had a MAC >33.0cm.

Ideally, all women should have a MAC measurement at their initial antenatal visit. Based on this study, 1 in 4 women attending the Diabetic Clinic and 1 in 8 women attending standard antenatal clinics should have their blood pressure measured using a large cuff.