TY - JOUR
T1 - Multivariate analysis of risk factors for operative delivery in nulliparous women
AU - Turcot, L.
AU - Marcoux, S.
AU - Fraser, W. D.
AU - Armson, B. A.
AU - Phalen-Kelly, K.
AU - Verrault, J. P.
AU - Paradis, G.
AU - Poulin, G.
AU - Moreau, L.
AU - Okun, N.
AU - Nimrod, C.
AU - Villeneuve, M.
AU - Joshi, A. K.
AU - Nault, C.
AU - Cohen, H.
AU - Weston, J.
AU - Doran, T.
AU - Jordan, A.
AU - Bernstein, P.
AU - Carroll, J.
AU - Pierce, C.
AU - Bayer, L.
AU - Kang, A.
AU - Bottoms, S.
AU - Norman, G.
AU - Galerneau, F.
AU - Jansen, P.
N1 - Funding Information:
Supported by operating grant No. MA-10556 from the Medical Research Council of Canada. S.M. holds a National Health Research Scholarship from Health Canada. W.D.F. receives salary support from the Medical Research Council of Canada (No. DG-401).
PY - 1997
Y1 - 1997
N2 - OBJECTIVE: Our purpose was to develop predictive models of operative delivery in nulliparous women on the basis of sociodemographic, anthropometric, and obstetric risk factors. STUDY DESIGN: Data were obtained prospectively on 925 nulliparous women in spontaneous term labor with a single fetus in cephalic presentation. Operative delivery was defined as either a midforceps or a cesarean delivery. Variables were grouped into two categories: those that could be assessed at admission and those appearing during labor. Multiple logistic regression was used to identify variables predictive of operative delivery. RESULTS: Among variables that can be documented at admission, independent predictors of operative delivery were maternal age and height, pregnancy weight gain, smoking status, gestational age, and admission cervical dilatation. Of these, maternal age ≤35 years was the most strongly related to operative delivery. When variables documented later during labor were added to this first model, variables retained in the second model were age and height, smoking status, presence of dystocia, epidural analgesia, and fetal heart rate tracing abnormalities. The adjusted odds ratio of operative delivery in the presence of epidural anesthesia was 3.4 (95% confidence interval 2.0 to 5.8). This association was similar in the presence or absence of dystocia. When the specificity was in the range of 85%, the first and second models have sensitivities of 34% and 48%, respectively, and positive predictive values of 39% and 46%, respectively, which is higher than the a priori risk of operative delivery in the study population (21%). CONCLUSIONS: The models, based on data easily available, may help to predict the need for midforceps or cesarean section in low-risk nulliparous women. Before application in a clinical setting, these statistical models require validation in a separate cohort. The observed association between epidural anesthesia and operative delivery deserves interest but clinical trials are required to determine whether this relation is causal.
AB - OBJECTIVE: Our purpose was to develop predictive models of operative delivery in nulliparous women on the basis of sociodemographic, anthropometric, and obstetric risk factors. STUDY DESIGN: Data were obtained prospectively on 925 nulliparous women in spontaneous term labor with a single fetus in cephalic presentation. Operative delivery was defined as either a midforceps or a cesarean delivery. Variables were grouped into two categories: those that could be assessed at admission and those appearing during labor. Multiple logistic regression was used to identify variables predictive of operative delivery. RESULTS: Among variables that can be documented at admission, independent predictors of operative delivery were maternal age and height, pregnancy weight gain, smoking status, gestational age, and admission cervical dilatation. Of these, maternal age ≤35 years was the most strongly related to operative delivery. When variables documented later during labor were added to this first model, variables retained in the second model were age and height, smoking status, presence of dystocia, epidural analgesia, and fetal heart rate tracing abnormalities. The adjusted odds ratio of operative delivery in the presence of epidural anesthesia was 3.4 (95% confidence interval 2.0 to 5.8). This association was similar in the presence or absence of dystocia. When the specificity was in the range of 85%, the first and second models have sensitivities of 34% and 48%, respectively, and positive predictive values of 39% and 46%, respectively, which is higher than the a priori risk of operative delivery in the study population (21%). CONCLUSIONS: The models, based on data easily available, may help to predict the need for midforceps or cesarean section in low-risk nulliparous women. Before application in a clinical setting, these statistical models require validation in a separate cohort. The observed association between epidural anesthesia and operative delivery deserves interest but clinical trials are required to determine whether this relation is causal.
KW - Cesarean section
KW - midforceps
KW - multivariate analysis
KW - risk factors
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U2 - 10.1016/S0002-9378(97)70505-2
DO - 10.1016/S0002-9378(97)70505-2
M3 - Article
C2 - 9065188
AN - SCOPUS:0031038273
SN - 0002-9378
VL - 176
SP - 395
EP - 402
JO - American journal of obstetrics and gynecology
JF - American journal of obstetrics and gynecology
IS - 2
ER -