Table 3.

Perinatal outcome stratified by BMI

Birth characteristic	Singleton births			Underweight vs. normal weight	Overweight vs. normal weight	Overweight vs. underweight
	Underweight (< 18.5 kg/m2 N=399)	Normal weight (18.5–24.9 kg/m2 N=2062)	Overweight (≥25 kg/m2 N=394)
Birth weight(g),%(n)
< 1500 g	0.75%(3/399)	0.58%(12/2062)	2.03%(8/394)	0.451	0.009	0.112
1500–2499 g	3.51%(14/399)	3.44%(71/2062)	4.82%(19/394)	0.522	0.129	0.239
≥2500 g	95.74%(382/399)	95.98%(1979/2062)	93.15%(367/394)	0.503	0.368	0.414
Z-score	0.04±0.96	−0.03±1.04	0.02±1.02	0.213	0.381	0.776
Very small for gestational age	1.75%(7/399)	1.31%(27/2062)	3.55%(14/394)	0.486	0.001	0.115
Small for gestational age	3.51%(14/399)	3.35%(69/2062)	3.81%(15/394)	0.869	0.645	0.823
Adequate for gestational age	85.96%(343/399)	86.42%(1782/2062)	83.76%(330/394)	0.808	0.163	0.386
Large for gestational age	8.77%(35/399)	8.92%(184/2062)	8.88%(35/394)	0.923	0.980	0.956
Gestation weeks at delivery (weeks),%(n)
< 32	0.75%(3/399)	0.82%(17/2062)	2.03%(8/394)	0.589	0.038	0.112
32–36	5.01%(20/399)	5.53%(114/2062)	7.36%(29/394)	0.401	0.113	0.126
≥37	94.24%(376/399)	93.65%(1931/2062)	90.61%(357/394)	0.484	0.354	0.371
Child’s sex, %(n)
Male	54.64%(218/399)	54.51%(1124/2062)	46.45%(183/394)	0.507	0.053	0.104
Female	45.36%(181/399)	45.49%(938/2062)	53.55%(211/394)	0.511	0.085	0.101
Mode of delivery,%(n)
Vaginal	39.09%(156/399)	34.58%(713/2062)	23.35%(92/394)	0.131	0.001	< 0.001
Cesarean section	60.91%(243/399)	65.42%(1349/2062)	76.65%(302/394)	0.223	0.033	0.022