Reassessing contemporary labour curves

OBJECTIVES: Our purpose was to analyse the pattern of labor progression in Low risk parturients in contemporary obstetric practice. STUDY DESIGN: We extracted detailed labor data from 1531 low risk parturients with a term, singleton, vertex fetus of normal birth weight after spontaneous onset of labor. Cesarean deliveries,instrumental deliveries and those needed oxytocin augmentation  were excluded.Those women whose new born needed resuscitation were also excluded. We used statistical measures to discover the average labor curve under contemporary practice.  We also computed the expected time interval of the cervix to reach the next centimeter, the expected rate of cervical dilation at each phase of labor.  RESULTS: Our average labor curve differs markedly from the Friedman curve . The cervix dilated substantially slower till 6 cm cervical dilatation. It took approximately 3.66 hours from 4 cm to 10 cm, compared with 2.5 hours under the Friedman curve. We observed no deceleration phase . Mean rate of cervical dilatation in active phase of labour was 1.42 cm/hr which is less than friedman’s rate of cervical dilatation which was 3 cm/hr. As per Zhang et al labour progress differentially at different degree of dilatation. &nbsp