Maternal collapse is an acute event involving the cardiorespiratory system and/or brain, causing reduced or absent conscious level at any point during pregnancy and up to 6 weeks postpartum. As collapse is not a reported event, the true incidence is difficult to estimate but it could be as high as 6:1000 births. However, where death has occurred, poor resuscitation has been a recurring theme.
The most common causes of collapse are vasovagal and epilepsy. Many cases are unpredictable, but some can be preceded by general deterioration as documented on observation charts. Physiological changes in pregnancy means that standard early warning scores cannot apply to pregnancy, and even those modified for pregnancy have failed to show changes in mortality and morbidity. However, the use of modified EWS is considered good practice.
UK Resuscitation Council website