Table 4

Association between measures of parental fertility and childhood asthma at 7 years in the MoBa

ExposureExposure groupNN cases (%)Unadjusted
RR (95% CI)
Adjusted*
RR (95% CI)
Previously treated for unwanted childlessnessNo68 0112827 (4.2)11
Yes6018325 (5.4)1.30 (1.16 to 1.46)1.26 (1.12 to 1.42)
Time to conception<6 months60 4852525 (4.2)11
6–12 months9431386 (4.1)0.98 (0.88 to 1.09)0.98 (0.88 to 1.09)
>12 months5881318 (5.4)1.30 (1.16 to 1.45)1.19 (1.06 to 1.34)
  • *Adjusted for maternal age, parity, education, smoking during pregnancy, prepregnancy BMI and maternal current asthma.

  • BMI, body mass index; MoBa, Norwegian Mother and Child Cohort Study; RR, relative risk.