Table 8.

Labour and delivery outcomes by vaginal or caesarean section delivery and neonatal outcomes for all multiparous women with a prolonged pregnancy following IOL by maternal BMI category

	Underweight	Normal	Overweight	Obese	P value
Pregnancy outcome by maternal BMI group (vaginal deliveries only n= 904)
Length stage 1 (hours) Median (IQR)	2.9 (1.4–5.0)	2.9 (1.7–4.5)	3.0 (1.7–4.4)	2.9 (1.6–4.7)	0.998
Length stage 2 (hours) Median (IQR)	0.4 (0.1–0.8)	0.3 (0.2–0.7)	0.3 (0.2–0.5)	0.3 (0.1–0.4)	<0.001*
Retained placenta, n (%)	0 (0.0)	19 (5.1)	11 (4.0)	7 (3.2)	0.386
Second-degree tear, n (%)	6 (16.2)	79 (21.3)	44 (15.9)	48 (21.9)	0.249
Third-degree tear, n (%)	1 (2.7)	3 (0.8)	5 (1.8)	3 (1.4)	0.619**
Episiotomy, n (%)	0 (0.0)	39 (10.5)	24 (8.7)	12 (5.5)	0.044*
PPH (>500 ml), n (%)	1 (2.7)	25 (6.7)	24 (8.7)	11 (5.0)	0.306
PPH (>1000 ml), n (%)	0 (0.0)	8 (2.2)	3 (1.1)	1 (0.5)	0.279**
Pregnancy outcome by maternal BMI group (caesarean section deliveries only n= 106)
PPH (>500 ml), n (%)	3 (100.0)	23 (71.9)	35 (77.8)	20 (83.3)	0.586**
PPH (>1000 ml), n (%)	0 (0.0)	3 (23.1)	5 (11.1)	5 (20.8)	0.509**
Neonatal outcome by maternal BMI group
Macrosomia, n (%) (n = 979)	4 (10.0)	24 (6.1)	24 (7.7)	26 (11.1)	0.159
Cord blood pH <7.2, n (%) (n = 878)	1 (3.0)	65 (18.3)	40 (14.4)	42 (20.0)	0.053
Cord blood pH <7.0, n (%) (n = 878)	0 (0.0)	2 (0.6)	2 (0.7)	2 (0.9)	0.913**
Apgar <7 (5-minutes), n (%) (n = 1004)	0 (0.0)	2 (0.5)	4 (1.2)	2 (0.8)	0.663**
Shoulder dystocia, n (%) (n = 1010)	1 (2.5)	14 (3.5)	13 (4.0)	7 (2.9)	0.877**
Stillbirth, n (n = 1010)	0	0	0	0	—

PPH, postpartum haemorrhage.

Values are presented as medians and interquartile range (IQR) for lengths of labour or total counts (n) and percentages (%) for all other analyses. Values presented in bold with * indicate that the trend was significant (P< 0.05 by Kruskal–Wallis test or chi-square test).

^**Indicates loss of power.

— Indicates that all values were zero so no chi-square statistic was computed.