Table 3. Subgroup analyses of the associations between ApoB, ApoB/ApoA-1 and preterm birth, stratified by pre-pregnancy BMI, maternal age and parity.
Subgroup ApoB ApoB ApoB/ApoA-1 ApoB/ApoA-1
OR (95% CI) P for interaction OR (95% CI) P for interaction
overall 2.33 (1.40,3.86) 4.1 (1.47,11.36)
Pre-pregnant BMI, kg/m2
<24 2.50 (1.43,4.33) 0.84 4.95 (1.60,15.21) 0.61
≥24 2.35 (0.23,24.32) 2.35 (0.23,24.32)
Maternal age at delivery, years
<35 2.18 (1.12,4.19) 0.18 2.92 (0.77,11.03) 0.29
≥35 2.56 (1.15,5.65) 6.44 (1.23,31.67)
Parity
Primiparous 1.66 (0.66,4.10) 0.33 1.20 (0.19,7.41) 0.27
Multiparous 2.72 (1.47,4.99) 7.27 (2.12,24.82)