The Physioflow Impedance device employs a continuous non-invasive method of measuring ten cardiac hemodynamic parameters including flow, resistance, contractility and fluid content. It involves the application of electrocardiogram (ECG) leads on the neck and the thorax to measure resistance of pulsatile blood flow. Its benefits are that it is non-invasive, low cost, and easy to operate. Thoracic impedance has been validated against the gold standard method of PAC. Although the Physioflow device has been validated in non-pregnant patients, its use in pregnant patients is very limited.