Table 1 Baseline characteristics of the study population
Baseline parameters | Early-onset group (n = 94) | Late-onset group (n = 230) | P value |
|---|---|---|---|
Mother’s age (years) | |||
 < 35 | 74 (78.7) | 170 (73.9) | 0.36 |
 ≥ 35 | 20 (21.3) | 60 (26.1) | |
BMI (kg/m2) | 21.63 ± 3.72 | 21.69 ± 3.18 | 0.88 |
Parity | |||
 Primipara | 69 (73.4) | 143 (62.2) | 0.05 |
 Multipara | 25 (26.6) | 87 (37.7) | |
Mode of conception | |||
 Natural | 88 (93.6) | 219 (95.2) | 0.76 |
 Artificial | 6 (6.4) | 11 (4.8) | |
TORCH | |||
 Negative | 39 (92.9) | 87 (87.0) | 0.47 |
 Positive | 3 (7.1) | 13 (13.0) | |
Additional abnormalities on MRI | 11 (18.3) | 3 (3.3) | 0.01 |
GA at initial diagnosis(weeks) | 22.96 ± 1.18 | 29.59 ± 2.21 | < 0.01 |