Arterial stiffness in normal pregnancy as assessed by digital pulse wave analysis by photoplethysmography – A longitudinal study

Introduction: It might in the future be valuable to screen for increased maternal arterial stiffness, i.e. low compliance, since it is associated with development of hypertensive complications in pregnancy. Digital pulse wave analysis (DPA) is an easy and manageable method for arterial stiffness assessment. We aimed to investigate gestational influence on DPA variables longitudinally, and establish gestational age-adjusted reference values in normal pregnancy. Methods: DPA measurements were performed longitudinally up to five times during pregnancy in 139 healthy women. Reference curves for DPA variables aging index (AI), b/a and d/a relative to gestational age were calculated with linear and polynomial mixed-effects models, and the influences of age and parity investigated with analysis of variance and analysis of covariance. A p < 0.05 was regarded significant. Results: All DPA variables were significantly associated with GA with best fit for a quadratic model. Arterial compliance peaked in the late second trimester. Age and parity independently influenced DPA variables but did not change the associations with gestational age. Conclusions: DPA reflects longitudinal changes in arterial compliance in normal pregnancy but individual variance of DPA changes were greater than the influence of GA. Normal distributions of AI, b/a and d/a at 14–24 weeks are presented, but it remains to show whether these can be used to detect pathological hemodynamic alterations in pregnancy.