Obstetrics

Pregnancy is divided into trimesters: the first trimester from the first day of a woman’s last period until the end of week 12, the second trimester from week 13 to the end of week 27, and the third trimester from week 29 to the end of 40 weeks. From as early as the first trimester, multisystem physiological changes develop rapidly. Anaesthetists must understand these changes, to enable them to provide optimum care. These physiological changes may become more significant as the pregnant population becomes increasingly medically complex. Modified early warning scores should be used when reviewing observations of pregnant women (and up until 6 weeks postnatally) in order to better interpret signs of deterioration.