Table 2.

Maternal characteristics by intrapartum referral rates in practices

			Rate of intrapartum referrals among nulliparous women in midwifery practices (tertiles)
		T1 (low)	T2	T3 (high)	Total
Nulliparous women		n = 35,180	n = 40,021	n = 37,605	n = 112,806	χ 2 p-value
Maternal age	<25	21.1	19.3	18.9	19.7	<0.001
	25-34	69.2	70.7	70.9	70.3
	≥35	9.7	10.0	10.3	10.0
Gestational age	37-41 + 0	82.8	82.9	83.2	82.9	0.025
	>41 + 0	17.2	17.1	16.8	17.1
Background	Dutch	80.8	84.9	82.3	82.8	<0.001
	Not Dutch	19.2	15.1	17.7	17.2
SES	Cat 1 (high)	21.2	23.2	23.0	22.5	<0.001
(Social economic status)	Cat 2	45.7	44.3	43.6	44.5
	Cat 3 (low)	33.1	32.5	33.4	33.0
Urbanization	Very urban	25.0	21.9	19.6	22.1	<0.001
	Intermediate	51.4	60.1	63.4	58.5
	Rural	23.6	18.0	16.9	19.4
Planned place of birth	Home	44.4	42.6	39.9	42.2	<0.001
	Hospital	44.9	48.8	51.6	48.5
	Other/unknown	10.6	8.7	8.6	9.2
Multiparous women		n = 41,273	n = 46,158	n = 42,708	n = 130,139
		%	%	%	%
Maternal age	<25	6.2	5.8	5.6	5.9	<0.001
	25-34	68.7	68.2	68.8	68.6
	≥35	25.1	26.0	25.5	25.6
Gestational age	37-41 + 0	83.9	83.5	84.2	83.9	0.001
	>41 + 0	16.1	16.5	15.8	16.1
Background	Dutch	80.3	82.6	78.9	80.6	<0.001
	Not Dutch	19.7	17.4	21.1	19.4
SES	Cat 1 (high)	22.6	25.4	25.1	24.4	<0.001
	Cat 2	47.9	45.7	44.6	46.0
	Cat 3 (low)	29.4	28.9	30.4	29.5
Urbanization	Very urban	19.3	16.3	14.9	16.8	<0.001
	Intermediate	52.9	62.6	65.7	60.5
	Rural	27.9	21.1	19.3	22.7
Planned place of birth	Home	52.0	50.1	46.9	49.6	<0.001
	Hospital	37.4	41.3	44.4	41.1
	Other/unknown	10.6	8.6	8.8	9.3

Missing values: parity 20, maternal age: 213; background: 2,350; SES 5,896, urbanization 286.