Table 2

Descriptive characteristics according to gestational age in Millennium Cohort Study children in England

VariableCharacteristicTotal
n=6031
(%)
Very preterm
(<32 weeks)
n=69 (%)
Moderately preterm
(32–33 weeks)
n=67 (%)
Late preterm
(34–36 weeks)
n=360 (%)
Early term
(37–38 weeks)
n=1258 (%)
Full term
(39–41 weeks)
n=4277 (%)
Maternal characteristics
UK-born4904 (85)55 (84) 56 (89)309 (88)1012 (84)3472 (85)
Marital statusMarried3823 (60)39 (52)41 (64)213 (56)833 (62)2697 (60)
De facto1508 (27)19 (30)18 (25)104 (31)282 (25)1085 (27)
Single700 (13)11 (18)8 (12)43 (13)143 (12)495 (13)
Education levelHigher1847 (30)22 (29)20 (29)112 (29)357 (27)1336 (30)
Medium826 (14)4 (5)8 (13)46 (13)171 (13)597 (14)
Lower2414 (42)26 (39)30 (50)164 (46)504 (42)1690 (41)
No formal941 (15)17 (27)7 (9)38 (12)226 (18)653 (14)
Socioeconomic statusHigh1709 (28)11 (17)19 (29)109 (30)346 (27)1224 (28)
Intermediate1356 (23)17 (21)16 (25)86 (24)266 (21)971 (23)
Low2966 (49)41 (62)32 (47)165 (47)646 (52)2082 (48)
EthnicityWhite4964 (86)50 (80) 53 (88)295 (86)965 (83)3501 (88)
Non-white1167 (14)19 (20)14 (12)65 (14)293 (17)776 (12)
Languages spoken at homeOnly English5191 (91)59 (90)59 (95)318 (92)1064 (90)3691 (92)
English and other839 (9)10 (10)8 (5)42 (8)194 (10)585 (8)
Pregnancy and perinatal characteristics
Maternal age, mean (years) 28.728.729.129.229.028.6
Kept smoking in pregnancy1142 (21)20 (31)12 (17)79 (23)252 (23)779 (21)
Moderate-high alcohol in pregnancy406 (7)6 (7)7 (12)30 (9)80 (7)283 (7)
Male sex3007 (50)33 (50)39 (65)184 (51)651 (52)2100 (49)
Multiple birth156 (2)19 (27)12 (19)56 (16)55 (4)14 (0)
Birth order: firstborn3574 (59)37 (53)29 (40)205 (59)810 (63)2493 (58)
Delivery methodVaginal3753 (79)15 (36)24 (40)189 (68)644 (66)2881 (85)
C/section1022 (21)30 (64)27 (60)96 (32)341 (34)528 (15)
Birth weightMean (kg)1.262.032.573.163.4
Admission to NICU535 (9)62 (94)56 (82)136 (38)110 (8)171 (4)
Age discharged home, mean (weeks)8.83.01.30.50.4
Breast feedingNever1647 (31)26 (37)20 (31)111 (34)365 (33)1141 (30)
0–1 months1641 (26)19 (27)25 (31)121 (31)362 (27)1132 (25)
2–5 months1242 (20)15 (23)14 (26)70 (18)244 (18)913 (20)
>6 months1501 (23)9 (12)8 (12)63 (16)302 (22)1137 (25)
Illness limiting activity383 (6)13 (18)10 (15)32 (8)83 (7)245 (6)
3+ hospital admissions364 (7)22 (34)8 (13)36 (11)96 (8)202 (5)
Oldest age group at school*2076 (34)15 (22)28 (40)115 (32)449 (36)1469 (34)
Middle age group at school1967 (32)25 (37)18 (29)134 (36)429 (33)1361 (32)
Youngest age group at school*1988 (33)29 (41)21 (32)111 (32)380 (30)1447 (34)
  • All percentages are weighted. *Descriptive data for children categorised as ‘oldest’, ‘middle’ and ‘youngest’ age groups at school are based on birth date in the school year. For children born between May and August 2008, who were also born before full term, we also assessed whether they would have been placed in the following school year for corrected age. However, due to statistical disclosure issues, this is not shown in table 2. NICU, neonatal intensive care unit.