Table 1 Demographic characteristics of retrospective study
Variables | Early bookers n = 29,698 | Late bookers n = 4686 | Significance |
|---|---|---|---|
Age (years): mean (range;SD) | 28.7 (14–52; 6) | 27.5 (13–32; 6.6) | P = 0.61 |
Teenage pregnancy = Yes : %(n) | 6.9 (2031) | 12.4 (579) | P < 0.001 |
Maternal age > 35 years = Yes: %(n) | 18.0 (5321) | 16.4 (769) | P = 0.011 |
Parity: mean | 0.85 | 1.14 | P < 0.001 |
White ethnicity = No: %(n) | 16.3 (4750) | 37.4 % (1668) | P < 0.001 |
Maternal employment = No: %(n) | 23.9 (4263) | 52 (1254) | P < 0.001 |
Paternal employment = No: %(n) | 4.8 (753) | 12.4 (227) | P < 0.001 |
IMD score % (n) | 5.9 (1068) | 10.4 (1875) | =0.031 |
Smoking status = Yes: %(n) | 14.7 (4348) | 18.8 (873) | P < 0.001 |
Body mass index (kg/m2): mean (range, SD) | 25.6 (17.5–52; 4.7) | 26.3 (17.6–54; 4.6) | P = 0.357 |