Cervical dilatation at diagnosis of active phase of labour determines the mode of delivery and peripartum outcomes: a retrospective study in a single tertiary centre in Malaysia.

BACKGROUND

There is an increasing trend of Caesarean section rate in Malaysia. Limited evidence demonstrated the benefits of changing the demarcation of the active phase of labour.

METHODS

This was a retrospective study of 3980 singletons, term pregnancy, spontaneous labouring women between 2015 and 2019 comparing outcomes between those with cervical dilation of 4 versus 6 cm at diagnosis of the active phase of labour.

RESULTS

A total of 3403 (85.5%) women had cervical dilatation of 4 cm, and 577 (14.5%) at 6 cm upon diagnosis of the active phase of labour. Women in 4 cm group were significantly heavier at delivery (p = 0.015) but significantly more multiparous women were in 6 cm group (p < 0.001). There were significantly fewer women in the 6 cm group who needed oxytocin infusion (p < 0.001) and epidural analgesia (p < 0.001) with significantly lower caesarean section rate (p < 0.001) done for fetal distress and poor progress (p < 0.001 both). The mean duration from diagnosis of the active phase of labour until delivery was significantly shorter in the 6 cm group (p < 0.001) with lighter mean birth weight (p = 0.019) and fewer neonates with arterial cord pH < 7.20 (p = 0.047) requiring neonatal intensive care unit admissions (p = 0.01). Multiparity (AOR = 0.488, p < 0.001), oxytocin augmentation (AOR = 0.487, p < 0.001) and active phase of labour diagnosed at 6 cm (AOR = 0.337, p < 0.001) reduced the risk of caesarean delivery. Caesarean delivery increased the risk of neonatal intensive care admission by 27% (AOR = 1.73, p < 0.001).

CONCLUSIONS

Active phase of labour at 6 cm cervical dilatation is associated with reduced primary caesarean delivery rate, labour intervention, shorter labour duration and fewer neonatal complications.