Impact of cardiovascular risk factors in vascular remodelling of pregnant women

Introduction Pregnancy is a physiological condition of hemodynamic overload, characterized by a progressive reduction of peripheral vascular resistance, which normalizes postpartum. Purpose To characterize arterial stiffness and endothelial function during pregnancy and postpartum and to investigate the impact of cardiovascular (CV) risk factors. The secondary aim was to explore the potential association between pulse wave velocity (PWV) and risk for preeclampsia. Methods Prospective cohort study including volunteer pregnant women (healthy, obese and/or hypertensive) recruited in a tertiary centre between 2019 and 2020, at their 1st or 3rd trimester of pregnancy. Women were evaluated at the first trimester [10–15 weeks, baseline], third trimester [30–35 weeks, peak of CV remodelling] of pregnancy as well as at the 1st month and 6th month after delivery (CV reverse remodelling stages). The evaluation included clinical characterization through questionnaires as well as arterial stiffness and endothelial assessment by PWV and EndoPAT, respectively. Kruskal-Wallis H test and Friedman test were used as appropriate to between and within groups comparisons. Bonferroni correction was applied. Spearman correlation was performed to determine the relationship between PWV and risk for preeclampsia. Results We included 34 pregnant women with a median age of 34 [26; 41]years, 50% being hypertensive and/or obese. Arterial stiffness decreased significantly from the 1st to the 3rd trimester (6.3 [5.3 to 7.8] cm/s vs 5.6 [4.9 to 7.3] cm/s, p<0.001), normalizing only at the 6th months (5.6 [4.9 to 7.3] cm/s vs 6.3 [5.5 to 8.3] cm/s, p=0.001). A significant deterioration of endothelial function became evident from 1st to 3rd trimester (logarithm of reactive hyperemia index [lnRHI]: 0.74 [0.05 to 1.20] vs 0.45 [0.22 to 0.79], p=0.020). However, its slight amelioration begun only 6 months after delivery (3rd trimester: lnRHI 0.45 [0.22 to 0.79] vs 6 months at postpartum: lnRHI 0.53 [0.10 to 1.01], p>0.99). Compared to the healthy pregnant women, the CV risk factors group showed a higher pulse wave velocity only at the peak of CV remodelling (5.6 [5.3 to 7.3] cm/s vs 5.6 [4.9 to 7.2] cm/s, p=0.016), without any other differences in other parameters of time points evaluated. Pulse wave velocity at the first trimester revealed a positive association with risk for preeclampsia (r=0.485, p=0.026). Conclusion Our cohort presented a significant decrease in vascular resistance during pregnancy and normalization at the 6th month after delivery. Pregnant women with cardiovascular risk factors showed an increased arterial stiffness in the 3rd trimester compared to healthy pregnant women. Pulse wave velocity correlated positively with the risk for preeclampsia. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Universidade do Porto/FMUP and FSE-Fundo Social Europeu; FCT - Foundation for Science and Technology