Table 5.

 ”Normal births”* for healthy women with low risk pregnancies by their planned place of birth at start of care in labour. Results for all women and restricted to those without complicating conditions at start of care in labour

Planned place of birth	No of events/births	Incidence of events/100 (99% CI)†	Odds ratio (99% CI)†
			Unadjusted	Adjusted‡
All women
Total:	48 080/64 105	61·5 (58·2 to 64·7)	(n=62 253)§
Obstetric unit	11 392/19 570	57·6 (54·1 to 60·9)	1.00	1.00
Home	14 566/16 619	87·9 (86·6 to 89·1)	5·30 (4·41 to 6·36)	4·47 (3·74 to 5·36)
Freestanding midwifery unit	9335/11 258	83·3 (81·3 to 85·1)	3·68 (3·03 to 4·46)	3·86 (3·16 to 4·72)
Alongside midwifery unit	12 787/16 658	76·0 (73·3 to 78·6)	2·33 (1·91 to 2·84)	2·50 (2·02 to 3·08)
Women without complicating conditions at start of care in labour
Total:	44 658/57 452	65·9 (62·6 to 69·1)	(n=55 849)§
Obstetric unit	9840/15 689	62·2 (58·6 to 65·6)	1.00	1.00
Home	13 902/15 675	89·0 (87·7 to 90·1)	4·85 (4·00 to 5·90)	4·12 (3·37 to 5·04)
Freestanding midwifery unit	8892/10 620	84·1 (82·0 to 86·0)	3·22 (2·61 to 3·96)	3·42 (2·74 to 4·27)
Alongside midwifery unit	12 024/15 468	77·1 (74·5 to 79·6)	2·04 (1·66 to 2·51)	2·21 (1·77 to 2·75)

*Defined as a birth without induction of labour, epidural or spinal analgesia, general anaesthesia, forceps or ventouse delivery, caesarean section, or episiotomy.^{9 10} Because normal birth is common, the odds ratios exaggerate the size of the association between planned place of birth and normal birth and do not reflect the ratio of the incidence of the outcome.

†Weighted to reflect each unit’s duration of participation and probability of being sampled; confidence intervals take account of the clustered nature of the data.

‡Adjusted for maternal age, ethnic group, understanding of English, marital or partner status, body mass index, deprivation score quintile, previous pregnancies, and weeks of gestation.

§Restricted to women who were not missing any potential confounder data.