Compare and contrast the physiological changes in the cardiovascular system in 
pregnancy at term and morbid obesity (BMI > 30).

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College Answer

The question was very specific for the cardiovascular system and therefore answers that 
described respiratory changes and airway modulation failed to score marks. This answer leant 
itself to a tabular format. Candidates are reminded to ensure they document the facts in the 
correct column i.e. obesity facts in the obesity column. The cardiovascular changes associated 
with term pregnancy are well described in various texts. Those associated with morbid obesity 
required some integration from various sources and would include a structured series of

comments such as heart rate (unchanged), blood pressure (tendency for hypertension), stoke 
volume (increased), cardiac output (increased), blood volume (increased – although perhaps 
decreased on a ml/kg basis), systolic function (preserved or increased), LV wall thickness 
increased. The pathological changes seen with the diseases associated with obesity are difficult 
to tease out and better answers identified this. Morbid obesity has a specific definition and 
stating this aided focus of the answers.