Table 2

Expected and observed percentage (n) below selected centiles: very preterm, late-to-moderate preterm, term: MBRRACE-UK vs UK-WHO (females)

Expected*Very preterm (<32 weeks)
(n=2230)
Late-to-moderate preterm (32–36 weeks)
(n=14 425)
Term (>36 weeks)
(n=296 106)
Observed
% (n)
MBRRACE-UK
Observed
% (n)
UK-WHO
Risk difference†
(95% CI)
Observed
% (n)
MBRRACE-UK
Observed
% (n)
UK-WHO
Risk difference†
(95% CI)
Observed
% (n)
MBRRACE-UK
Observed
% (n)
UK-WHO
Risk difference†
(95% CI)
Below 0.4th
(0.38%)
0.85 (19)1.21 (27)0.36 (−0.23 to  0.95)0.76 (109)0.55 (80)−0.20 (−0.39 to  −0.01)0.40 (1193)0.28 (832)−0.12 (−0.15 to  −0.09)
Below 2nd
(2.28%)
2.78 (62)3.54 (79)0.76 (−0.26 to  1.79)2.83 (408)2.31 (333)−0.52 (−0.88 to  −0.15)1.98 (5860)1.44 (4274)−0.54 (−0.60 to  −0.47)
Below 9th
(9.13%)
7.85 (175)10.90 (243)3.05 (0.13 to  4.76)8.89 (1282)7.83 (1129)−1.06 (−1.70 to  −0.42)8.04 (23 809)6.43 (19 037)−1.61 (−1.74 to  −1.48)
Below 25th
(25.24%)
22.06 (492)25.52 (569)3.45 (0.96 to  5.95)22.90 (3304)20.28 (2925)−2.62 (−3.58 to  −1.68)23.70 (70 182)20.33 (60 190)−3.37 (−3.59 to  −3.16)
Below 50th (50%)44.57 (994)46.59 (1039)2.02 (−0.90 to  4.94)49.29 (7110)43.40 (6260)−5.89 (−7.04 to  −4.74)48.97 (144 996)44.66 (132 244)−4.31 (−4.56 to  −4.05)
Below 75th (74.76%)76.19 (1699)74.04 (1651)−2.15 (−4.69 to   0.38)77.64 (11 199)70.29 (10 140)−7.34 (−8.35 to  −6.33)74.43 (220 379)71.57 (211 917)−2.86 (−3.08 to  −2.63)
Below 91st (90.87%)92.91 (2072)90.58 (2020)−2.33 (−3.95 to  −0.72)92.00 (13 271)87.36 (12 601)−4.64 (−5.34 to  −3.94)90.74 (268 673)89.21 (264 147)−1.53 (−1.68 to  −1.38)
Below 98th (97.72%)96.64 (2155)95.56 (2131)−1.08 (−2.21 to  −0.06)96.80 (13 964)94.52 (13 634)−2.29 (−2.76 to  −1.82)97.53 (288 778)96.99 (287 200)−0.53 (−0.62 to  −0.45)
Below 99.6th
(99.62%)
97.58 (2176)96.86 (2160)−0.72 (−1.68 to  0.25)98.74 (14 243)97.40 (14 050)−1.34 (−1.66 to  −1.02)99.46 (294 501)99.30 (294 045)−0.15 (−0.19 to  −0.11)
  • *Centiles and expected percentages based on 0.67 SD score spacing between centiles.8

  • †Risk difference=prevalence below a given centile according to UK-WHO minus prevalence according to MBRRACE-UK.