Prediction of duration of active labor in nulliparous women at term.
We have assessed the independent predictors of duration of active labor in nulliparous women at term. Using a cohort of 1067 nulliparae in spontaneous labor at > 37.0 weeks with singleton fetuses in vertex presentation, multivariate analysis was used to identify independent predictors of duration of active labor. Duration of active labor was 4.1 +/- 2.4 hours. Stepwise linear regression selected 10 independent predictors of duration of active labor: gestational age at delivery ( P < 0.001), race ( P = 0.014), obstetric risk factors ( P = 0.022), amniotomy ( P < 0.001), fundal height ( P = 0.005), cervical dilation on admission ( P < 0.001), frequency of contractions ( P < 0.001), station of presenting part ( P < 0.001), oxytocin ( P < 0.001), and epidural use ( P < 0.001). A prediction formula incorporating the 10 predictors accounted for 51% of the total variance of the observed duration of active labor. Ten variables are independent predictors of duration of active labor; when incorporated in a prediction formula they account for > 50% of the variability of duration of labor in nulliparous women.
Incerti
Maddalena
M
Department of Obstetrics and Gynecology, San Gerardo Hospital, University of Milano-Bicocca, Monza, Italy.
Locatelli
Anna
A
Ghidini
Alessandro
A
Ciriello
Elena
E
Malberti
Silvia
S
Consonni
Sara
S
Pezzullo
John C
JC
D000328:Adult; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007747:Labor Stage, First; D016015:Logistic Models; D011247:Pregnancy; D015203:Reproducibility of Results; D012189:Retrospective Studies; D047929:Term Birth / Q000502:physiology*; D013997:Time Factors; D014590:Uterine Contraction