However, due to the modification in their immune systems to accommodate their developing fetus and adaptations in their body as a result of the hormonal and physical changes, they are at greater risk of developing complications should they acquire the illness. The enlarging uterus presses on the diaphragm and together with changes in the lungs such as reduced tidal volume, congestion and localized oedema, make the woman more prone to complications such as pneumonia and Adult Respiratory Distress Syndrome (ARDS). Recent reports have shown that the percentage of hospitalised cases requiring transfer to ICU within each gestational band is similar (27, 25, 24%); and the death rate amongst hospitalised patients within each gestational age group is also remarkably uniform (10, 6, 9%). This may imply that outcome in severely ill pregnant women is independent of gestational age after severe illness is established [14] .