Table 2

Characteristics of preterm cohorts from grade A studies reporting outcome of all pregnancies (stillbirths and live births)

Reference		Cohort birth period		Exclusions (details in text)		Geographical cohort		Antenatal steroids		Postnatal surfactant		Age at survival	Proportion of live births surviving for each week of gestation (%)
Reference		Cohort birth period		Exclusions (details in text)		Geographical cohort		Antenatal steroids		Postnatal surfactant		Age at survival	23	24	25	26	27
EPICure⁴	Mar 95–Dec 95	No	Yes	Yes (64%)	Yes (87%)	dis	11	27	47
Cartlidge⁵	1993–1994	Yes	Yes	Yes^2-150	Yes^2-150	neo	5	26	59	69	74
Tin⁶	1991–1994	Yes	Yes	Yes^2-150	Yes^2-150	1 y	2	17	35	53	70
Kilpatrick⁷	1990–1994	Yes	No	Yes (83%)	Yes (95%)	dis		49	78	83
Kramer⁸	Jul 89–Dec 93	No	No	Yes (18%)	Yes (100%)	6 m	19	48	25	75	71
Lefebvre⁹	1987–1992	Yes	No	Yes^2-150	Yes^2-150	dis	0	23	50	64	78
Allen¹⁰	May 88–Sep 91	No	No	No	Yes^2-150	6 m	17	56	79
Gray¹¹	Jun 88–May 90	Yes	No	Yes^2-150	No	dis		57	68	83	89
Tin⁶	1987–1990	Yes	Yes	Yes^2-150	Yes^2-150	1 y	18	17	33	45	64
Synnes¹²	1983–1989	No	No	No	No	dis	16	43	55	63	77
EC Study¹³	1986	Yes	Yes	No	No	dis	17	13	27	50	36
EC Study¹³	1986	Yes	Yes	No	No	dis	0	0	40	18	50
Nicholl¹⁴	1983–1989	Yes	No	No	No	dis	8	43	59	65	85
EC Study¹³	1985	Yes	Yes	No	No	dis	0	5	19	48	48
Tin⁶	1983–1986	Yes	Yes	No	No	1 y	3	10	21	42	59
EC Study¹³	1983	Yes	Yes	No	No	dis	0	0	14	37	52
					Combined estimate		10	27	44	55	67
					(95% CI)		(8–12)	(24–30)	(41–47)	(52–58)	(64–70)

↵2-150 Percentage not specified.
neo, neonatal period (28 days); 1 y, 1 year of age; dis, discharge from hospital; 6 m, 6 months of age.