The basis for this collaborative project was to develop a computational model of a cardiovascular network during various stages of pregnancy. The development of the foetus causes various changes in the cardiovascular network of the pregnant woman. For example, the hormone progesterone can relax the walls of the blood vessels which can lead to lower blood pressures. As the cardiovascular network of the foetus develops there will be more interaction between the cardiovascular systems of the mother and foetus. The project will involve the use of experimental data to aid the development of the model. An efficient implicit solver has been developed for the one-dimensional blood flow equations, which, uses Lagrange multipliers to constrain the conservation of mass and conservation of total pressure at vessel junctions. The cardiovascular system considered will be a closed loop system containing systemic arteries/veins and pulmonary arteries/veins, together with a heart model and valves. The arterial system and venous system are connected via a five element Windkessel model.