Table 3. Mean and standard deviation of SI by BMI group and maternal age.

	BMI Group
	19–24 kg/m2	25–29 kg/m2	≥ 30 kg/m2
	Mean ± SD	Mean ± SD	Mean ± SD	p-value
0–20 mina	0.78 ± 0.16	0.76 ± 0.14	0.70 ± 0.14b	0.02
21–40 mina	0.72 ± 0.15	0.73 ± 0.14	0.66 ± 0.12c	0.03
41–60 mina	0.71 ± 0.17	0.72 ± 0.15	0.66 ± 0.14c	0.04
61–90 mina	0.69 ± 0.16	0.73 ± 0.14	0.66 ± 0.11c	0.02
91–120 min	0.69 ± 0.14	0.71 ± 0.15	0.65 ± 0.12	0.06
	Maternal Age
	≤ 19y	20–34y	≥ 35y
	Mean ± SD	Mean ± SD	Mean ± SD	p-value
0–20 min	0.77 ± 0.16	0.74 ± 0.15	0.70 ± 0.12	0.24
21–40 min	0.72 ± 0.16	0.70 ± 0.14	0.65 ± 0.01	0.41
41–60 min	0.70 ± 0.18	0.70 ± 0.14	0.62 ± 0.17	0.23
61–90 min	0.70 ± 0.16	0.70 ± 0.13	0.62 ± 0.12	0.26
91–120 min	0.67 ± 0.15	0.69 ± 0.13	0.61 ± 0.13	0.15

a The variation in SI values was significant by ANOVA (P < 0.05).

b Significant difference from 19–24 by Tukey test (P<0.05)

c Significant difference from 25–29 by Tukey test (P<0.05)