BackgroundThe purpose of the present study was to investigate pregnancy-related changes in the maternal serum lipid profile and endothelial function. Methods and ResultsAs part of the population-based, prospective cohort Cardiovascular Risk in Young Finns study conducted in Finland, 57 pregnant Finnish women and 62 control women matched for age and smoking were examined throughout gestation. Serum triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined and concomitantly endothelium-dependent brachial artery flow mediated dilation (FMD) was measured by ultrasound. During pregnancy serum TC, LDL-C, HDL-C, TG and very-low-density lipoprotein cholesterol increased significantly when compared with the non-pregnant state (p<0.001 for each) and towards the end of pregnancy (p<0.001, p<0.001, p=0.007, p<0.001, p<0.001). FMD increased towards the end of pregnancy and there was a statistically significant direct correlation between gestational age and FMD% (r=0.345, p=0.010). Brachial artery diameter at rest and FMD% were negatively correlated in pregnant (r=-0.280, p=0.035) and non-pregnant women (r=-0.360, p<0.004). The univariate correlation analysis showed a direct correlation between maternal serum TC (r=0.333, p=0.012) and TG (r=0.366, p=0.006) and FMD%, whereas a negative non-significant correlation was found in non-pregnant women. In a multivariate model, vessel size ( =-0.436, p=0.001) and TG ( =0.502, p<0.001) were the most powerful predictors for FMD% in pregnancy, the influence of other lipids was non-significant. Conclusions In healthy pregnant women increased gestational age is associated with improved endothelium-dependent vasodilation responses regardless of concurrently appearing lipid changes. (Circ J 2006; 70: 768 -772)

BackgroundThe aims were to evaluate the effect of pregnancy on carotid artery elasticity and determine the associations between maternal lipids, endothelial function and arterial elasticity during pregnancy.MethodsWe examined 99 pregnant and 99 matched non-pregnant control women as part of a population-based prospective cohort study. Carotid artery elasticity indexes; carotid artery distensibility (CAD), Young’s elastic modulus (YEM) and stiffness index (SI) as well as brachial artery flow-mediated dilation (FMD) were assessed using ultrasound; serum lipid levels were also determined.ResultsSI was 57% and YEM 75% higher and CAD 36% lower in the third trimester group than the corresponding values in the first trimester group. Serum cholesterol and triglyceride levels were significantly higher in women at the end of the pregnancy than at the beginning of pregnancy (P < 0.001) and in controls (P < 0.001). In multivariate analysis, gestational age was the only independent correlate of arterial elasticity in pregnant women. In controls, age (P ≤ 0.001) and common carotid diameter (P = 0.001-0.029) were associated with SI, YEM and CAD.ConclusionsThe present study revealed that carotid artery elasticity declined towards the end of the pregnancy; this neither is straight correlating with maternal hyperlipidemia or the diameter of the carotid artery nor is it associated with changes in endothelial function.

The aim of the present study was to evaluate pregnancy-related changes in autonomic regulatory functions in healthy subjects. We studied cardiovascular autonomic responses to head-up tilt (HUT) in 28 pregnant women during the third trimester of pregnancy and 3 months after parturition. The maternal ECG and non-invasive beat-to-beat blood pressure were recorded in the horizontal position (left-lateral position) and during HUT in the upright position. Stroke volume was assessed from blood pressure signal by using the arterial pulse contour method. Heart rate variability (HRV) was analysed in frequency domain, and baroreflex sensitivity by the cross-spectral and the sequence methods. In the horizontal position, all frequency components of HRV were lower during pregnancy than 3 months after parturition (P < 0.01 to <0.001), while pregnancy had no influence on normalized low frequency and high frequency powers. During pregnancy haemodynamics was well balanced with only minor changes in response to postural change while haemodynamic responses to HUT were more remarkable after parturition. In pregnant women HRV and especially its very low frequency component increased in response to HUT, whereas at 3 months after parturition the direction of these changes was opposite. Parasympathetic deactivation towards term is likely to contribute to increased heart rate and cardiac output at rest, whereas restored sympathetic modulation with modest responses may contribute stable peripheral resistance and sufficient placental blood supply under stimulated conditions. It is important to understand cardiovascular autonomic nervous system and haemodynamic control in normal pregnancy before being able to judge whether they are dysregulated in complicated pregnancies.

Improvement of FMD in normal pregnancy was not affected by increase in hsCRP concentration. We found an association with IL-6 and FMD but we believe that improvement in endothelial function during normal pregnancy is not caused by variation in hsCRP, IL-6 or TNF-alpha.