Background Obesity is associated with increased central arterial stiffness (CAS) in non-pregnant women, with increased CAS being an independent predictor of cardiovascular risk. However, the relationship between CAS and obesity during pregnancy is not known. We aimed to determine the relationship between obesity and CAS in late pregnancy.

Methods 48 women with singleton pregnancies (≥28 weeks gestation) were recruited. All measurements were carried out supine in a quiet temperature-controlled room. Blood pressure (systolic (SBP) and diastolic (DBP)) was measured using a semi-automatic oscillometric sphygmomanometer at the brachial artery. CAS was measured using the SphygmoCor to determine augmentation index (AI) and augmentation pressure (AP). Pulse wave velocity (PWV) was measured by Vicorder. Data are expressed as mean±SEM. Significance was taken as p<0.05.

Results Mean gestation at study was 35±3 weeks. AI, AP, brachial and central SBP and DBP and PWV were 5±13%, 2±5 mm Hg, 129±11 mm Hg, 79±8 mm Hg, 112±12 mm Hg, 82±9 mm Hg and 5.4±0.6 m/s (mean±SEM), respectively. When women were divided into age, gestation and blood pressure matched body mass index (BMI) tertiles based on their BMI at booking (21.5±2.3, 28.8±2.4 and 40.2±5.3; n=16/tertile), there was no difference in any measurements of CAS across the tertiles of BMI (all p>0.05).

Conclusion In contrast to the situation in non-pregnant women, obesity itself does not increase central arterial stiffness in the third trimester of pregnancy in an age, gestation and blood pressure matched cohort.