Table 1.
Comparison of clinical characteristics between the two groups.
| Characteristics | Study group (N = 164) | Control group (N = 328) | P value |
|---|---|---|---|
| Maternal age (years) | 33.97 ± 4.25 | 30.48 ± 3.65 | <0.001 |
| Gravidity | 3.9 ± 1.1 | 2.2 ± 1.0 | <0.001 |
| Gestational age (w) | 35.7 ± 5.2 | 38.2 ± 2.1 | <0.05 |
| Birth weight (g) | 2676 ± 1014 | 3245 ± 70 | <0.001 |
| Body mass index | 23.8 ± 3.3 | 24.2 ± 2.9 | >0.05 |
| Proportion of primiparous women | 145 (88.4%) | 283 (86.2%) | >0.05 |
| Received ART | 17 (10.3%) | 26 (7.9%) | >0.05 |
| Other adverse pregnancy histories | 11 (6.7%) | 19 (5.8%) | >0.05 |