Unsuspected 34-week pregnancy presenting as acute hypoxaemic respiratory failure.

An obese body habitus may interfere with diagnosis of potentially life-threatening conditions. This report describes an obese woman who presented with acute hypoxemic respiratory failure and diffuse infiltrates. Her body habitus disguised her parturient abdomen and she could not provide a history because she was intubated and paralysed. Only after a urine pregnancy test was undertaken did it become apparent that she was pregnant and the diagnosis of pre-eclampsia with pulmonary oedema was considered. Urine pregnancy tests are part of the standard work-up for abdominal pain in women of childbearing age, but are not viewed as part of the work-up for respiratory distress or diffuse radiographic infiltrates. This case illustrates the value of obtaining a pregnancy test in all women, particularly those with obese body habitus, who present with respiratory failure of unclear aetiology.