Table 2

Maternal characteristics

Number (%)* of casesNumber (%)* of controlsOR (95% CI)
n=30n=757
Maternal factors
Maternal age (years)
 <3524 (80)596 (79)1
 35+6 (20)160 (21)1.09 (0.46 to 2.57)
Ethnic group
 White21 (70)598 (79)1
 Non-white9 (30)156 (21)1.83 (0.84 to 3.96)
Socioeconomic status
 Managerial8 (27)189 (26)1
 Other employed/unemployed22 (73)548 (74)0.99 (0.44 to 2.25)
Marital status
 Married/cohabiting25 (83)630 (84)1
 Single5 (17)124 (16)0.98 (0.37 to 2.59)
Smoking status during pregnancy
 Did not smoke26 (87)581 (77)1
 Smoked4 (13)173 (23)0.52 (0.18 to 1.50)
Parity
 012 (40)330 (44)1
 1+18 (60)427 (56)1.16 (0.55 to 2.44)
Body mass index
 Normal or overweight (<30)18 (64)564 (77)1
 Obese (≥30)10 (36)170 (23)1.84 (0.83 to 4.07)
Multiple pregnancy
 Yes1 (3)8 (1)1
 No29 (97)746 (99)3.21 (0.07 to 25.31)
Pre-existing medical conditions
 Yes11 (37)242 (32)1.22 (0.57 to 2.60)
 No19 (63)510 (68)1
Previous pregnancy complications
 Yes8 (27)148 (20)1.49 (0.65 to 3.42)
 No22 (73)607 (80)1
  • *Percentage of individuals with complete data.