Table 3.

Chance of vaginal birth by weight category and gestational weight gain for women attempting a trial of labor after two previous cesareans (n = 22,762)

Weight category weight gain		Vaginal birth (%), n = 12,192
Underweight	Below IOM guidelines	62.4
	Within IOM guidelines	52.1
	Above IOM guidelines	59.4
Normal weight	Below IOM guidelines	57.8
	Within IOM guidelines	58.7
	Above IOM guidelines	55
Overweight	Below IOM guidelines	56.9
	Within IOM guidelines	52.6
	Above IOM guidelines	51.3a
Obese	Below IOM guidelines	52.7
	Within IOM guidelines	49
	Above IOM guidelines	47.4a

Abbreviation: IOM, Institute of Medicine.

^aWithin group differences based on gestational weight gain (p < 0.01).