Abstract P097: Maternal Vascular Changes during Pregnancy may Persist Postpartum
Introduction: Higher parity (number of births) is associated with increased subclinical cardiovascular disease (CVD) in mid-life and older women, and with increased risk of CVD overall. In the only study of reproductive age women, common carotid artery intima-media thickness (CCA IMT) was greater after each birth. Prospective studies of arterial change throughout normal pregnancy are lacking; without them it is unclear whether unhealthy changes of the vasculature during pregnancy persist postpartum and raise women’s risk of CVD. The goal of this study was to prospectively assess normal vascular adaptation in healthy pregnant women. Hypotheses: During the course of healthy pregnancy: 1. CCA adventitial diameter (AD) will increase, then return to baseline postpartum, 2. CCA IMT will initially thin, then thicken as pregnancy progresses, then return to baseline postpartum, and 3. brachial artery distensibility will not change. Methods: We assessed 43 healthy women during each trimester of their first pregnancy and 6-8 weeks postpartum with B-mode ultrasound imaging of the CCA IMT and AD, independent predictors of CVD risk. Brachial artery distensibility, representing elasticity of the artery, was measured using the DynaPulse wave form analyzer. Linear mixed models were used to compare measures of CCA IMT, adventitial diameter, and brachial artery distensibility at each time point, after adjustment for age and pre-pregnancy BMI. Results: There were 37 women (age 28.2 ± 4.5 years, pre-pregnant BMI 24.4 ± 3.2 kg/m 2 ) with uncomplicated pregnancies. Six women with pregnancy complications were excluded from these analyses. After adjustment for age and pre-pregnancy BMI, mean (SE) CCA AD (mm) increased each trimester, from 6.38(0.08) in the 1 st trimester to 6.92(0.09) in the 3 rd trimester, and returned to baseline, 6.35 (0.07), postpartum. Pairwise comparisons were all statistically significant at p&lt;.01. Mean (SE)CCA IMT (mm) was increased postpartum (0.567 (0.01)) compared to 1 st (0.539 (0.01)) and 2 nd trimester values (0.546 (0.01), p &lt; .05 for each). Mean (SE) brachial artery distensibility (%/mmHg) decreased from 7.64 (0.28) 1st trimester to 6.84 (0.21) 3rd trimester (p &lt; .01) and then remained unchanged at 6.82 (0.21) postpartum. Conclusions: As we hypothesized, in uncomplicated first pregnancies CCA AD increased throughout and returned to baseline postpartum. However, contrary to our hypotheses, CCA IMT increased postpartum, and the brachial artery stiffened during pregnancy and remained stiffer 6-8 weeks postpartum. In uncomplicated first pregnancies, some vascular changes resolved (CCA AD) and others persisted (CCA IMT and brachial artery stiffness). Whether this indicates that persistence of specific vascular effects of pregnancy may inform long term CVD risk remains to be explored.