Table 1 General characteristics of the study population
N | Preterm n(%) 206 (100) | Term n(%) 412 (100) | P a value |
|---|---|---|---|
Maternal age (years) [mean ± SD] | 28.35 ± 5.32 | 28.25 ± 4.70 | 0.808 |
Maternal age (years) | 0.732 | ||
< 25 | 47 (22.8) | 99 (24.0) | |
25–34 | 130 (63.1) | 264 (64.1) | |
≥ 35 | 29 (14.1) | 49 (11.9) | |
Neonatal gender | 1.000 | ||
Male | 121 (58.7) | 242 (58.7) | |
Female | 85 (41.3) | 170 (41.3) | |
Gestational age at blood sampling (weeks) | 1.000 | ||
< 14 | 68 (33.0) | 136 (33.0) | |
14–27 | 116 (56.3) | 232 (56.3) | |
≥ 28 | 22 (10.7) | 44 (10.7) | |
pre pregnancy BMI b | 0.060 | ||
< 18.5 | 60 (29.6) | 98 (24.0) | |
18.5–23.9 | 120 (59.1) | 280 (68.4) | |
≥ 24.0 | 23 (11.3) | 31 (7.6) | |
Literacy | 0.647 | ||
Primary | 7 (3.4) | 18 (4.4) | |
Secondary | 122 (59.5) | 255 (61.9) | |
Graduate and above | 76 (37.1) | 139 (33.7) | |
Household yearly income (yuan) | 0.747 | ||
< 50,000 | 94 (45.6) | 197 (47.8) | |
≥ 50,000 | 71 (34.5) | 143 (34.7) | |
Unclear | 41 (19.9) | 72 (17.5) | |
Parity | 0.586 | ||
Nullipara | 124 (60.8) | 241 (58.5) | |
Multipara | 80 (39.2) | 171 (41.5) | |
Abortions | 0.610 | ||
0 | 101 (49.5) | 195 (47.3) | |
≥ 1 | 103 (50.5) | 217 (52.7) | |
Second-hand smoking | 0.930 | ||
Yes | 25 (12.1) | 49 (11.9) | |
No | 181 (87.9) | 363 (88.1) | |
Maternal reproductive tract infection | 0.935 | ||
Yes | 29 (14.1) | 59 (14.3) | |
No | 178 (85.9) | 353 (85.7) |