Table 1 Characteristics of the included and excluded pregnant women
From: Concentrations of perfluoroalkyl and polyfluoroalkyl substances and blood glucose in pregnant women
Characteristics | Included (N = 856) N (%) / Mean ± SD | Excluded (N = 369) N (%) / Mean ± SD | P-value of Student’s t-test or Chi-square test |
|---|---|---|---|
Maternal age at enrollment (years) | |||
 Mean ± SD | 27.8 ± 3.3 | 27.8 ± 3.4 | 0.784 |
  < 25 | 128 (15.0) | 56 (15.2) | 0.454 |
 25–35 | 697 (81.4) | 294 (79.7) |  |
  ≥ 35 | 31 (3.6) | 19 (5.1) |  |
Pre-pregnancy BMI (kg/m2) | |||
 Mean ± SD | 20.4 ± 2.4 | 20.5 ± 2.4 | 0.732 |
  < 18.5 | 176 (20.9) | 68 (18.7) | 0.666 |
 18.5–24.9 | 627 (74.6) | 279 (76.6) |  |
  ≥ 25 | 37 (4.4) | 17 (4.7) |  |
Maternal education | |||
 Below high school | 76 (8.9) | 43 (11.7) | 0.314 |
 High School | 125 (14.6) | 50 (13.5) |  |
 College or above | 653 (76.5) | 276 (74.8) |  |
Per capita household income (CNY) | |||
  < 4000 | 176 (21.0) | 57 (16.2) | 0.151 |
 4000–8000 | 495 (59.1) | 224 (63.8) |  |
  > 8000 | 167 (19.9) | 70 (19.9) |  |
Passive smoking | |||
 Yes | 295 (40.4) | 109 (43.9) | 0.320 |
 No | 436 (59.6) | 139 (56.1) |  |
Pregnancy complication | |||
 Yes | 53 (6.19) | 22 (6.0) | 0.878 |
 No | 803 (93.8) | 347 (90.0) |  |
History of abortion and stillbirth | |||
 Yes | 320 (37.4) | 147 (39.8) | 0.271 |
 No | 536 (62.6) | 222 (60.2) |  |
Parity | |||
 0 | 732 (86.1) | 296 (80.8) | 0.020 |
  ≥ 1 | 118 (13.9) | 70 (19.1) |  |