Table 1.

Factors associated with cesarean delivery following vaginal delivery

Variable	Vaginal delivery (N=10,178)	Cesarean delivery (N=218)	P valuea	Adjusted odds ratiob	95% confidence interval
BMI at delivery (kg/m2)c	29.1 ± 4.6d	31.0 ± 5.6	< 0.001	1.08	1.06 – 1.11
Change in BMI:			< 0.001
lost more than 2 kg/m2	9.0	4.6		0.41	0.21 – 0.78
lost < 2 kg/m2 to gained < 2 kg/m2	77.3	72.1		(ref)
gained 2 kg/m2 to < 4 kg/m2	9.6	14.7		1.53	1.03 – 2.27
gained 4 kg/m2 or more	4.1	8.7		1.99	1.19 – 3.34
Race/ethnicity:			0.002
non – Hispanic white	69.9	61.0		(ref)
non – Hispanic black	5.9	11.9		1.91	1.08 – 2.72
Hispanic	1.6	2.8		1.87	0.85 – 4.23
Asian	6.3	6.4		1.23	0.68 – 2.01
other race	16.3	17.9		1.19	0.70 – 1.53
Operative vaginal deliveryc	13.6	22.5	< 0.001	1.91	1.40 – 2.64

^aP values are from a chi square test for categorical variables, student t test for continuous variables.

^bIn addition to the other factors listed here, odds ratios are also adjusted for parity, maternal age, and diabetes at subsequent delivery and time between deliveries, factors which were not significant in multivariable models.

^cMeasured at the time of index delivery.

^dDichotomous variables are presented as percent of corresponding column, and continuous variables are presented as mean ± standard deviation.

^eMeasured at the time of subsequent delivery.