Table 2 Risk of any major congenital malformation in children born to mothers with asthma
Cases (n = 5124)Controls (n = 30053)Adjusted OR‡ (95% CI)p Value
n (%)†n (%)†
Maternal asthma status
No asthma diagnosis or medications before delivery4420 (86.3)26235 (87.3)Reference
Asthma diagnosis or medication§ before delivery704 (13.7)3818 (12.7)1.10 (1.01 to 1.20)0.032
Diagnosis with no medication before delivery171 (3.3)881 (2.9)1.17 (0.99 to 1.39)0.071
Asthma medication§ but no diagnosis before delivery183 (3.6)968 (3.2)1.13 (0.96 to 1.33)0.132
Diagnosis and asthma medication§ before delivery350 (6.8)1969 (6.6)1.06 (0.94 to 1.20)0.329
⩾1 asthma exacerbation during pregnancy18 (<0.5)94 (<0.5)1.09 (0.65 to 1.82)0.754
⩾1 medication exposure during pregnancy*
Any asthma medication410 (8.0)2240 (7.5)1.05 (0.94 to 1.18)0.367
    Short-acting β agonist375 (7.3)2085 (6.9)1.06 (0.94 to 1.19)0.336
    Inhaled corticosteroid220 (4.3)1209 (4.0)1.07 (0.92 to 1.24)0.407
    Long-acting β agonist25 (<0.5)131 (<0.5)1.12 (0.72 to 1.75)0.614
    Oral corticosteroid46 (0.9)216 (0.7)1.23 (0.89 to 1.69)0.201
    Other bronchodilator medication¶13 (<0.5)72 (<0.5)1.05 (0.59 to 1.87)0.872
    Other anti-inflammatory medication**9 (<0.5)27 (<0.5)2.02 (0.96 to 4.28)0.065
  • *Reference groups are mothers with no prescriptions for the selected drug group in pregnancy.

  • †Proportion of cases or controls whose mothers had a diagnosis or at least one selected drug prescription in pregnancy.

  • ‡Odds ratios (95% confidence intervals) adjusted for maternal age at birth of case or control child; maternal smoking status, body mass index, socioeconomic status, sex of the child, gestation of pregnancy had no confounding effects.

  • §Any asthma medication except oral corticosteroids during pregnancy or in the year before the pregnancy.

  • ¶Aminophylline, theophylline, ephedrine, orciprenaline, titropium or ipratropium.

  • **Cromoglicate, nedocromil, montelukast or zafirlukast.