Maternal Cardiovascular Function in Normal Pregnancy: Evidence of Maladaptation to Chronic Volume Overload

Hypertension. 2016 Apr;67(4):754-62. doi: 10.1161/HYPERTENSIONAHA.115.06667. Epub 2016 Jan 25.


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.

Keywords: LV hypertrophy; diastolic dysfunction; echocardiography; pregnancy; remodeling; tissue Doppler.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological / physiology*
  • Adult
  • Cardiac Output, High / diagnostic imaging*
  • Cardiac Output, High / physiopathology
  • Cross-Sectional Studies
  • Echocardiography, Doppler / methods
  • Female
  • Gestational Age
  • Humans
  • Myocardial Contraction / physiology
  • Pregnancy / physiology*
  • Prospective Studies
  • Reference Values
  • Risk Assessment
  • Statistics, Nonparametric
  • Stroke Volume / physiology*
  • Ultrasonography, Prenatal / methods
  • United Kingdom
  • Vascular Resistance / physiology
  • Ventricular Function, Left / physiology*