Main findings
The principal findings of this study were: (1) We developed a prediction
model, composed of five variables (maternal age, maternal height,
parity, cervical effacement, and total birth weight of twins), for
cesarean delivery after IOL in twin pregnant women; (2) In addition, a
nomogram for predicting the risk of cesarean delivery after IOL in twin
pregnancies was developed; and (3) The developed prediction model showed
good performance in both the development and external validation
databases.
To predict the risk of cesarean delivery after IOL in twin pregnancies,
we compared many clinical variables including maternal age, maternal
height, maternal weight, pregestational BMI, parity, gestational age at
IOL, gestational age at delivery, method of conception, cervical
examination, chorionicity, presentation and birth weight of each twin,
and total birth weight of twins. We found some independent risk factors
that increased the risk of cesarean delivery, and the final prediction
model included maternal age, parity, maternal height, cervical
effacement, and total birth weight of twins. Maternal age, maternal
height, and cervical effacement are also known risk factors in singleton
pregnancies.25,26 The birth weight-related variable
retained in the final model was the total birth weight of twins.
To our knowledge, this is the first study to develop a prediction model
for cesarean delivery after IOL in twin pregnancies. Several studies
have reported many prediction models after IOL in singleton
pregnancies.25,27 The AUROC of the prediction model in
the current study was 0.742 (95% CI 0.700-0.785) in the training set,
0.733 (95% CI 0.671-0.794) in the test set, and 0.714 (95% CI
0.650-0.777) in the validation cohort, which is similar to the reported
AUROC of the prediction models in singleton pregnancies (AUROC 0.787
[95% CI 0.786-0.788] in the study by Rossi et
al.27, 0.79 [95% CI, 0.74-0.83] in the study by
Levine et al.25).