Table 1 Demographic and clinical characteristics of study participants
|  | sPTB (N = 32) | Term Birth (N = 16) | p-value |
|---|---|---|---|
Mother | |||
 Maternal age (years), mean (SD) | 27.16 (4.14) | 27.19 (3.90) | 0.98 |
 Pre-pregnancy BMI, mean (SD) | 20.06 (2.22) | 18.80 (1.13) | 0.04 |
 College or above education, N (%) | 17 (53.10) | 7 (43.80) | 0.54 |
 Family income > ¥3000/month, N (%) | 17 (53.10) | 9 (56.30) | 0.84 |
 Primiparity, N (%) | 28 (87.50) | 13 (81.30) | 0.67 |
 Passive smoking, N (%) | 22 (68.80) | 8 (50.00) | 0.21 |
 Alcohol use, N (%) | 1 (3.10) | 2 (12.50) | 0.25 |
Placenta | |||
 Placental surface area (cm2), mean (SD)a | 260.41 (59.17) | 286.43 (41.91) | 0.12 |
 Placenta thickness (cm), mean (SD) | 2.19 (0.47) | 2.34 (0.47) | 0.29 |
Newborn | |||
 Gestational age (weeks), mean (SD) | 35.09 (1.35) | 39.63 (1.09) | < 0.001 |
 Gender (male), N (%) | 59.40% (19/32) | 56.30% (9/16) | 0.84 |
 Birth weight (gram), mean (SD) | 2436.53 (461.48) | 2999.38 (268.28) | < 0.001 |
 Birth length (cm), mean (SD) | 46.50 (2.70) | 49.44 (1.63) | < 0.001 |
 Head circumference (cm), mean (SD) | 31.13 (1.31) | 32.38 (1.31) | 0.003 |