Table 4

Asthma risk factors, birth weights and asthma symptoms in groups categorised by high or low z-score for first trimester crown–rump length and second trimester biparietal diameter

Persistent high growthGrowth decelerationGrowth accelerationPersistent low growth
Proportion exposed to antenatal maternal smoking26% (79/302)19% (20/103)32% (50/154)30% (75/247)
Proportion with maternal asthma17% (52/302)22% (23/103)14% (21/154)18% (44/247)
Proportion male sex57% (169/294)42% (43/102)67% (100/150)43% (102/240)***
Mean difference in birth weight, g0−39 (−150 to 70)−12 (−108 to 83)−89 (−172 to −6)*
Odds for ever wheeze†1
n=190		1.63 (0.72 to 3.69)
n=62		1.83 (0.90 to 3.74)
n=82		3.31 (1.82 to 6.02)**
n=140
Odds for wheeze in the last 12 months†1
n=190		0.56 (0.17 to 1.84)
n=62		1.81 (0.81 to 4.02)
n=84		2.38 (1.20 to 4.76)*
n=141
Odds for seen doctor with wheeze in last 12 months†1
n=190		1.29 (0.34 to 3.81)
n=62		1.39 (0.51 to 3.79)
n=84		2.63 (1.18 to 5.87)*
n=141
Odds for ever asthma†1
n=190		1.52 (0.54 to 4.32)
n=62		1.22 (0.47 to 3.15)
n=83		2.84 (1.35 to 6.01)**
n=140
Odds for doctor-confirmed asthma†1
n=190		1.94 (0.68 to 5.58)
n=62		1.45 (0.55 to 3.81)
n=83		3.00 (1.38 to 6.54)**
n=140
Odds for asthma and wheeze in last 12 months†1
n=190		0.50 (0.09 to 3.05)
n=62		1.15 (0.31 to 4.26)
n=83		2.17 (0.91 to 5.14)
n=140
Mean FEV1 (ml)‡0
n=77		−8 (−73 to 56)
n=26		−73 (−127 to −18)**
n=42		−27 (−77 to 22)
n=63
Mean FVC (ml)‡0
n=96		−36 (−104 to 32)
n=36		−83 (−144 to −21)**
n=47		−53 (−106 to −0)*
n=87
Mean FEF25–75 (ml/s)‡0
n=97		0.003 (−0.133 to 0.139)
n=36		−0.126 (−0.249 to −0.003)*
n=47		−0.035 (−0.140 to 0.071)
n=86
Mean postbronchodilator FEV1 (ml)‡0
n=50		−108 (−197 to −18)*
n=17		−95 (−179 to −11)*
n=22		−67 (−139 to 5)
n=35

  • ↵* p<0.05;

  • ↵** p<0.01 compared with persistent high growth;

  • ↵*** p<0.001 across groups.

  • ↵† Adjusted for maternal smoking status at first trimester scan, history of maternal asthma, birth order, Scottish Index of Multiple Deprivation (SIMD),17 birth weight, breast feeding, use of antibiotics by the child in the first year of life and maternal intake of vitamin C, vitamin D and zinc.

  • ↵‡ Adjusted for gestational age at scan, sex, maternal smoking status at first trimester scan, history of maternal asthma, maternal height, Scottish Index of Multiple Deprivation (SIMD), birth weight and child's height aged 5 years.

  • FEF25–75, forced expiratory flow between 25% and 75% of FVC; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity.