Table 3.

Final model including independent risk factors for cesarean delivery among nulliparous women undergoing IOL at term.

Characteristic	Unadjusted OR (95% CI)	P	Adjusted OR (95% CI)	P
Maternal age (years)*	1.17 (1.01–1.37)	0.04	1.26 (1.05–1.51)	0.01
Height (cm)*	1.25 (1.11–1.40)	<0.001	1.37 (1.20–1.56)	<0.001
BMI (kg/m2)*	1.33 (1.18–1.49)	<0.001	1.41 (1.23–1.63)	<0.001
Weight change during pregnancy (kg)*	1.15 (1.01–1.31)	0.04	1.29 (1.11–1.50)	0.001
Gestational age (weeks)*	1.12 (1.00–1.25)	0.06	1.40 (1.20–1.63)	<0.001
Hypertensive disorder	1.56 (1.08–2.27)	0.02	1.72 (1.05–2.81)	0.03
Diabetes mellitus		<0.001		0.001
Gestational vs. none	1.70 (1.02–2.84)		1.81 (1.00–3.30)
Pregestational vs. none	7.94 (2.53–24.91)		8.35 (2.37–29.48)
Initial cervical dilation		<0.001		<0.001
Closed (0 points) vs. 3–6 cm (2–3 points)	3.08 (1.82–5.19)		4.03 (2.22–7.33)
1–2 cm (1 point) vs. 3–6 cm (2–3 points)	2.05 (1.31–3.21)		2.74 (1.64–4.58)

Abbreviations: BMI, body mass index; CI, confidence interval; OR, odds ratio

^*OR per 5 year increase in age, 5 cm decrease in height, 5 kg/m² increase in BMI, 5 kg increase in weight change during pregnancy, and 1 week increase in gestational age

All variables listed in this table were retained in the final multivariable model.