Table 2

Likelihood of specific perinatal and mortality outcomes and smoking status at first booking

Outcome/smoking status at bookingInfant having perinatal or mortality outcomeAll infants (N)
NColumn %Row %Crude ORAdjusted* ORPAF (%)
HR (95% CI)HR (95% CI)
Neonatal mortality†1843100.00.3697 003
Never smoked78942.80.2391 8611.00 (reference)1.00 (reference)6.7
Current smoker50327.30.3159 8191.56 (1.40 to 1.75)1.32 (1.17 to 1.49)
Former smoker1055.70.259 3260.88 (0.72 to 1.08)0.82 (0.66 to 1.00)
Unknown/missing44624.20.585 9972.58 (2.30 to 2.90)2.01 (1.75 to 2.30)
Postneonatal mortality‡1074100.00.2697 003
Never smoked38335.70.1391 8611.00 (reference)1.00 (reference)22.3
Current smoker44441.30.3159 8192.85 (2.48 to 3.27)2.18 (1.87 to 2.53)
Former smoker726.70.159 3261.24 (0.97 to 1.60)1.16 (0.90 to 1.49)
Unknown/missing17516.30.285 9972.08 (1.74 to 2.49)1.88 (1.54 to 2.29)
Small for gestational age§, ¶56 588100.08.4676 095
Never smoked22 53539.85.8391 0681.00 (reference)1.00 (reference)27.5
Current smoker24 86343.915.6159 4333.02 (2.96 to 3.08)2.67 (2.62 to 2.73)
Former smoker38266.86.559 2031.13 (1.09 to 1.17)1.03 (0.99 to 1.06)
Unknown/missing53649.58.166 3911.44 (1.39 to 1.48)1.31 (1.26 to 1.35)
Premature delivery¶, **40 492100.06.0677 449
Never smoked19 85549.05.1391 7481.00 (reference)1.00 (reference)8.8
Current smoker12 39630.67.8159 7611.58 (1.54 to 1.61)1.41 (1.37 to 1.44)
Former smoker30027.45.159 3081.00 (0.96 to 1.04)0.93 (0.89 to 0.97)
Unknown/missing523912.97.966 6321.60 (1.55 to 1.65)1.49 (1.44 to 1.54)
  • *Adjusted for: maternal age; infant gender, SIMD; mothers socioeconomic status; fathers socioeconomic status; parity; mode of delivery and country of birth.

  • †Neonatal mortality describes a baby that has died during the first 28 days of life.

  • ‡Postneonatal mortality is defined as those infant deaths in which the infant is more than 28 days and less than1 year of age.

  • §Under 10th centile—small for gestational age.

  • ¶Unknown/missing data excluded from modelling.

  • **Birth of a baby at fewer than 37 weeks gestational age.

  • PAF, population attributable fraction; SIMD, Scottish Index of Multiple Deprivation.