Background-Pregnant women with congenital heart disease (CHD) are susceptible to cardiovascular, obstetric, and offspring complications. In women with CHD, cardiac dysfunction may compromise uteroplacental flow and contribute to the increased incidence of obstetric and offspring events. Methods and Results-We performed a prospective multicenter cohort study of pregnant women with CHD and healthy pregnant women. We compared clinical, laboratory, echocardiographic, and uteroplacental Doppler flow (UDF) parameters at 20 and 32 weeks gestation, and pregnancy outcome. We related cardiovascular parameters to UDF parameters and pregnancy outcome in women with CHD. We included 209 women with CHD and 70 healthy women. Cardiovascular parameters (N-terminal pro-B-type natriuretic peptide, left and right ventricular function) differed between both groups. UDF parameters were impaired in CHD women (umbilical artery pulsatility and resistance index at 32 weeks in CHD versus healthy women, P=0.0085 and P=0.017). The following cardiovascular parameters prepregnancy and at 20 weeks gestation were associated with UDF (umbilical artery resistance index) at 32 weeks at multivariable analysis: (1) right ventricular function (tricuspid annular plane systolic excursion) (P=0.002), (2) high N-terminal pro-B-type natriuretic peptide (P=0.085), (3) systemic (P=0.001), and (4) pulmonary (P=0.045) atrioventricular valve regurgitation. Women with CHD had more obstetric (58.9% versus 32.9%, P<0.0001) and offspring events (35.4% versus 18.6%, P=0.008) than healthy women. Impaired UDF was associated with adverse obstetric and offspring outcome. Conclusions-UDF parameters are abnormal in pregnant women with CHD. Cardiovascular function is associated with an abnormal pattern of UDF. Compromised UDF may be a key factor in the high incidence of offspring and obstetric complications in this population.

No abstract

The hemodynamic adaptation to pregnancy in the HYPERT and NONTHROMB subgroups differs from that in THROMB and controls by an early pregnancy rise in alpha-atrial natriuretic peptide. As a consequence, the early pregnancy plasma volume expansion in the NONTHROMB and HYPERT subgroups is less than in normal parous controls.

No abstract

ISRCTN Register, www.isrctn.org, ISRCTN40512715.

OBJECTIVE: Pregnancy induces a smaller rise in plasma volume in formerly preeclanmptic women with a pre-existent subnormal plasma volume than in their counterparts with a normal plasma volume. These women also have a three times higher recurrence rate ofpregnancy-induced hypertensive disorders. In this study we tested the hypothesis that a subnormal plasma volume in these women is related to a lower capacitance of their venous compartment. METHODS: In 31 nonpregnantformerlypreeclamptic-women with a subnormalplasma volume and eight parous controls, we infused intravenously 500 mL of a modified gelatin solution over 30 minutes. Before and after infusion we measured the circulating levels of ot-atrial natriuretic peptide (a-ANP) and active plasma renin concentration (APRC). During volume loading, we recorded the change in heart rate, stroke volume, and cardiac output using pulse contour analysis. We measured the ratio ofpercent change in blood volume and percent change in cardiac output during volume loading as a markerfor venous capacitance.RESULTS: During volume loading, patients dffferedfrom controls by a larger rise in oa-ANP, pulse rate, and cardiac output, and by a lower estimated venous capacitance. The concomitant response ofstroke volume and APRC did not differ appreciably between groups. CONCLUSION: Formerly preeclamptic women with a subnormal plasma volume dfferfrom controls with a normal plasma volume by a reduced venous capacitance. These results support our hypothesis that, in these women, a subnornal plasma volume indicates the presence of a subnormal venous capacitance. (J Soc

Relaxin mediates renal and mesenteric vascular adaptations to pregnancy by increasing endothelium-dependent vasodilation and compliance and decreasing myogenic reactivity. Diet-induced overweight and obesity are associated with impaired endothelial dysfunction and vascular remodeling leading to a reduction in arterial diameter. In this study, we tested the hypothesis that local vascular responses to relaxin are impaired in diet-induced overweight female rats on a high-fat cafeteria-style diet for 9 wk. Rats were chronically infused with either relaxin or placebo for 5 days, and vascular responses were measured in isolated mesenteric arteries and the perfused kidney. Diet-induced overweight significantly increased sensitivity to phenylephrine (by 17%) and vessel wall thickness, and reduced renal perfusion flow (RPFF; by 16%), but did not affect flow-mediated vasodilation, myogenic reactivity, and vascular compliance. In the normal weight rats, relaxin treatment significantly enhanced flow-mediated vasodilation (2.67-fold), decreased myogenic reactivity, and reduced sensitivity to phenylephrine (by 28%), but had no effect on compliance or RPFF. NO blockade by l-NAME diminished most relaxin-mediated effects. In diet-induced overweight rats, the vasodilator effects of relaxin were markedly reduced for flow-mediated vasodilation, sensitivity to phenylephrine, and myogenic response compared with the normal diet rats, mostly persistent under l-NAME. Our data demonstrate that some of the vasodilator responses to in vivo relaxin administration are impaired in isolated mesenteric arteries and the perfused kidney in diet-induced overweight female rats. This does not result from a decrease in Rxfp1 (relaxin family peptide receptor) expression but is likely to result from downstream disruption to endothelial-dependent mechanisms in diet-induced overweight animals.

To obtain data for maternal stroke volume and cardiac output during pregnancy, it is preferable to use a non-invasive, accurate and reproducible method. In this aspect, impedance cardiography is an excellent technique which is also highly accessible and easy to perform. This paper is a comprehensive review on the published literature about impedance cardiography and highlights the strengths and limitations of its applications in obstetrics.