Inconsistent definitions of labour progress and over-medicalisation cause unnecessary harm during birth

Abstract

Nanna Maaløe and colleagues argue that resource challenges, unclear and outdated clinical practice guidelines, and lack of women’s perspectives lead to overdiagnosis and overtreatment of prolonged labour

Fig 1

Physiological and pathophysiological evidence on functional and dysfunctional labour, and discordance with clinical practice. In the functional labour cycle, contractions gradually increase in strength until the cervix is fully dilated and vaginal birth occurs. Relaxation of the uterine muscle between contractions allows for fetal and myometrial re-oxygenation. Possible problems with this natural contraction-relaxation cycle during labour are: (1) Women with true prolonged labour often have either reduced flow of the body’s natural oxytocin (eg, because of pain, fear, or mental distress), or increased lactic acid in the capillaries of the uterine muscle. The acidity (lower pH) inhibits calcium ion channels, which in turn decreases contractile strength and limits oxytocin’s effect; (2) Too powerful or too frequent contractions—resulting, for example, from augmentation of labour with synthetic oxytocin—decrease placental perfusion and reduce oxygen flow to the fetus; and (3) In a smaller subgroup of women, progress of labour arrests because of mechanical disproportion between the fetal presenting part and the maternal pelvis despite a functional labour cycle

Fig 2

WHO’s thresholds for prolonged first stage of active labour using the partogram and labour care guide