Non-invasive assessment of maternal hemodynamics in early pregnancy

Objectives: Non-invasive assessment of maternal hemodynamics in early pregnancy may be promising in evaluating maternal hemodynamic (mal)adaptation to pregnancy. We explored usage of applanation tonometry and Doppler ultrasound for assessment of cardiac output (CO), systemic vascular resistance (SVR) and arterial stiffness in early pregnancy.

Methods: Pregnant healthy nulliparous women were studied during first trimester. Radial artery pressure waveform (augmentation index(AIx)), carotid-femoral pulse wave velocity (PWV) and cardiac output (CO) were measured by applanation tonometry (SphygmoCor), electrocardiogram and Doppler ultrasound (USCOM) and related to maternal demographic characteristics and literature concerning advanced pregnancy and non-pregnant subjects.

Results: 116 women were studied during gestational age range of 7(+2)-14weeks. Systolic and diastolic central blood pressure were correlated with systolic and diastolic brachial blood pressure respectively. Both measures of arterial stiffness (heart rate corrected AIx(AIx@75) and PWV) were correlated. AIx@75, PWV and SVR were correlated with central mean arterial pressure. CO was negatively correlated with AIx and associated with BMI. PWV was associated with age and BMI, whereas SVR was associated with age.

Conclusions: Applanation tonometry and Doppler Ultrasound for assessment of maternal hemodynamics in early pregnancy revealed similar associations between different hemodynamic parameters and maternal characteristics as have previously been reported in advanced pregnancy and non-pregnant subjects. The SphygmoCor and the USCOM appear to be reliable methods for the assessment of maternal hemodynamics in early pregnancy. Obtaining a comprehensive hemodynamic profile using these modalities may offer insight in maternal (mal)adaptation to pregnancy. Future work needs to be done relating such measures to pregnancy outcome.