THE IMPACT OF CERVICAL DILATATION AT ADMISSION ON LABOUR OUTCOMES

Abstract

Objective of the study was to examine the outcome differences between women presenting in early and late phase of labor. We evaluated all low-risk women with term (37 – 42 weeks), singleton ,vertex presentation who presented in early labor (<4 cm) or late labor ($ \geq $4 cm) at R G Kar Medical College and Hospital, Kolkata in a one year period (Jan to Dec 2007). A total of 2463 women in early labor (group 1) were compared to 2704 women in late labor (group 2). The primary outcome was the rate of caesarean section (CS) and secondary outcomes were length of labor, labor augmentation with artificial rupture of membrane (ARM) and oxytocin, operative vaginal delivery, fetal weight, and five minute apgar score. The risk of caesarean section was seen to decrease with increasing cervical dilatation on admission to labor ward (Correlation coefficient – 0.87 for nulliparous and – 0.68 for parous women and p < 0.001 for both). 16.1% of nulliparous and 14% multiparous presenting with <4cm dilatation underwent caesarean sections whereas of those who had >4cm cervical dilatation at admission only 9.6% nulliparas and 5.9% multipara required Caesarean section. Women presenting at <4 cm dilatation also spent less time in labor before their first vaginal examination; they had a higher rate of ARM and oxytocin administration as methods for labor augmentation. The study confirms that interventions like caesarean delivery, operative vaginal delivery and augmentation of labor are increased if patients are admitted in the early labor. However, the fact that delayed admission has advantages in this regard needs to be corroborated through further studies.