Table 5

Risk of miscarriage in Norway between 2009 and 2013 according to the women’s own birth record (n=258 954*)

ExposureTotal number of pregnancies excluding induced abortionsNumber of miscarriages (%)Adjusted† odds ratio (95% CI)
Gestational age at delivery:
 Preterm10 5991396 (13.2)1.05 (0.99 to 1.12)
 Term194 91024 462 (12.6)Ref
 Post-term38 0444955 (13.0)1.04 (1.00 to 1.08)
Fetal growth:
 Small for gestational age26 3973598 (13.6)1.08 (1.04 to 1.13)
 Normal for gestational age195 35824 571 (12.6)Ref
 Large for gestational age21 5482618 (12.2)0.97 (0.93 to 1.02)
Pre-eclampsia:
 No252 34631 951 (12.7)Ref
 Yes6608852 (12.9)1.06 (0.98 to 1.15)
  • * 76 903 pregnancies excluded because they resulted in an induced abortion; 1412 pregnancies excluded because the woman was born before the medical birth register was set up (1967); and 83 932 pregnancies excluded because the woman was born outside of Norway.

  • Adjusted for age.