A review of the effects of Valsalva manoeuvre in labour and birth

The Valsalva manoeuvre (VM) is a normal physiological event that occurs during the second active phase of labour. In women with medical conditions that may be exacerbated by the Valsalva, caesarean birth may be recommended. This carries with it its own potential for maternal morbidity, and thus it is important that women are appropriately counselled about the mode of delivery most suited to their individual situation. It is possible to avoid VM with spontaneous pushing rather than reverting to caesarean birth. Neuraxial analgesia and instrumental delivery may also be used to avoid prolonged VM. We outline the effect of VM on the various organ systems in pregnancy and summarise the available evidence on its implication.