Maternal Cardiovascular Function in Normal Pregnancy

Abstract

Abstract-The aim of this study was to investigate cardiac functional status in pregnancy using a comprehensive approach taking into account the simultaneous changes in loading and geometry, as well as maternal age and anthropometric indices. This was a prospective cross-sectional study of 559 nulliparous pregnant women assessed at 4 time points during pregnancy and at 1 year postpartum. All women underwent conventional echocardiography and tissue Doppler velocities and strain rate analysis at multiple cardiac sites. Mean arterial pressure and total vascular resistance index significantly decreased (both P<0.001) during the first 2 trimesters of pregnancy and increased thereafter. Stroke volume index and cardiac index showed the opposite trend compared with mean arterial pressure and total vascular resistance index (both P<0.05). Myocardial and ventricular function were significantly enhanced in the first 2 trimesters but progressively declined thereafter. By the end of pregnancy, significant chamber diastolic dysfunction and impaired myocardial relaxation was evident in 17.9% and 28.4% of women, respectively, whereas myocardial contractility was preserved. There was full recovery of cardiac function at 1 year postpartum. Cardiovascular changes during pregnancy are thought to represent a physiological adaptation to volume overload. The findings of a drop in stroke volume index, impaired myocardial relaxation with diastolic dysfunction, and a tendency toward eccentric remodeling in a significant proportion of cases at term are suggestive of cardiovascular maladaptation to the volume-overloaded state in some apparently normal pregnancies. These unexpected cardiovascular findings have important implications for the management of both normal and pathological pregnancy states. Melchiorre et al Cardiac Function and Geometry in Pregnancy 755changes in maternal loading conditions, cardiac geometry, as well as age and anthropometric indices. MethodsThis was a prospective cross-sectional study performed over a 5-year period from June 2008 to February 2013. Healthy nulliparous women with singleton viable pregnancy were recruited consecutively from the routine antenatal clinic at St George's Hospital, University of London. The local institutional review committee approved the study, and all participants provided written informed consent. Women who subsequently developed adverse maternal complications, such as diabetes mellitus, preeclampsia, peripartum cardiomyopathy, pregnancy complication, or any other medical comorbidity, were excluded from the analysis. Women were recruited at 4 time points during pregnancy (11-14, 20-23, 28-32, and 37-39 weeks' gestation) and at 1 year postpartum after pregnancy care in our institution. A group of 50 nonpregnant healthy volunteer nulliparous women matched for age was also assessed to derive baseline echocardiographic values. All groups were matched for ethnicity and maternal age. To ensure that we recruited optimally healthy women, we also excluded women with a prepregnancy body mass...

Pulmonary artery dilatation during normal pregnancy

“…To assess stroke volume Savu et al [2] used the Doppler technique, while we used the biplane Simpson method for the calculation. Surprisingly, unlike other studies, which reported both RA and RV enlargement [1,14,15], we observed only mild RA dilatation in group A ( Table 4). The reason why we did not observe RV enlargement remains unclear and requires further examination.…”

“…Most of the haemodynamic changes and subsequent cardiac remodelling observed in all women in our study are characteristic of normal pregnancy and are consistent with findings from other studies [1,2,[10][11][12][13][14]. This applies to an increase in heart rate, LV stroke volume, and LVCO, and to a decrease in SVR.…”

“…The possible explanation of these discrepancies may result from the difference in the schedule of visits (especially V1 and V2) in our study in comparison with those reported in other studies. Other investigators, who planned three or four visits during pregnancy, observed RA dilatation between the first and third trimesters (after 34 gestational weeks), when the increase in plasma volume is the highest [14,15]. Moreover, Melchiorre et al [14] reported that tricuspid annular plane systolic excursion (TAPSE) declined significantly near term and returned to normal values postpartum, whereas in a study by Ducas et al [15], the TAPSE values between the first and third trimesters were stable, which is in line with our results.…”

Pregnancy: An Underutilized Window of Opportunity to Improve Long-term Maternal and Infant Health—An Appeal for Continuous Family Care and Interdisciplinary Communication

“…Even in normal pregnancy, myocardial and ventricular function decline after the second trimester (187). The findings of a drop in stroke volume index, impaired myocardial relaxation with diastolic dysfunction, and eccentric remodeling at term are suggestive of cardiovascular maladaptation to the volume overload in some apparently normal pregnancies.…”

Flow-mediated dilation and peripheral arterial tonometry are disturbed in preeclampsia and reflect different aspects of endothelial function

“…We found an increase in NRL and MPV during pregnancy, supporting this theory of increased inflammatory response at the end of pregnancy. A recent paper by Melchiorre et al (14) describes an increase in total vascular resistance and endsystolic wall stress at term as a consequence of the persistent overload of volume during pregnancy. During normal pregnancy, there is an overt systemic vasodilatation at all levels of the vascular tree, resulting in a higher shear stress, possibly compromising microvascular endothelial function.…”