Lack of utility of standard labor curves in the prediction of progression during labor induction

OBJECTIVE: This study was undertaken to determine whether patients undergoi ng labor induction can be reliably evaluated by means of standard labor ass essment curves. STUDY DESIGN: In this retrospective chart review of 123 patients who underw ent cervical ripening and induction of labor, Friedman's standard labor cur ves were used for comparison. Statistical analysis was performed with the S tudent t test. RESULTS: Nulliparous and parous patients undergoing cervical ripening spent more time in active-phase labor than standard expectations of labor progre ssion would indicate (12.7 +/- 7.8 vs 5.9 +/- 3.4 hours for nulli-parous wo men, P < .001; 7.9 +/- 6.4 vs 2.5 +/- 1.5 hours for parous women, P < .001) . Nulliparous and parous patients who were delivered vaginally spent more t ime in active labor than did their respective standard historical control p opulations (10.3 +/- 8.0 vs 5.9 +/- 3.4 hours for nulliparous women, P < .0 01; 7.0 +/- 6.0 vs 2.5 +/- 1.5 hours for parous women, P <.001). CONCLUSION: Standard methods for the evaluation of labor adequacy and predi ction of the likelihood of vaginal delivery may not apply to patients under going cervical ripening.