Lack of analgesic effect of systemically administered morphine or pethidine on labour pain

Abstract

It is concluded that labour pain is not sensitive to systemically administered morphine or pethidine. These drugs only cause heavy sedation. It therefore seems unethical and medically incorrect to meet parturients' requests for pain relief by giving them sedation. Considering the well documented negative effects on newborn infants we also believe systemic pethidine should be avoided in labour.