Table 1 Maternal, placental, and fetal characteristics grouped by FT-LBW and FT-NBW
|  | FT-LBW (N = 86) | FT-NBW (N = 79) | P value |
|---|---|---|---|
Mothers | |||
 Age (year), mean (SD) | 27.49 (5.88) | 28.87 (4.28) | 0.08 |
 Pre-pregnancy BMI, mean (SD) | 19.60 (2.66) | 19.90 (2.20) | 0.43 |
 College or above, N (%) | 27 (31.40) | 40 (50.63) | 0.03 |
 Family income ≤ ¥3000/month, N (%) | 57 (66.28) | 34 (43.04) | 0.003 |
 Married, N (%) | 84 (97.67) | 76 (96.20) | 0.67 |
 Environmental tobacco smoke, N (%) | 31 (36.05) | 17 (21.52) | 0.03 |
 Primiparity, N (%) | 64 (74.42) | 56 (70.89) | 0.51 |
 Alcohol use, N (%) | 5 (5.81) | 2 (2.53) | 0.45 |
Placenta | |||
 Weight (g), mean (SD) | 466.24 (54.58) | 504.80 (56.07) | < 0.0001 |
 Major axis length (cm), mean (SD) | 18.60 (2.19) | 19.86 (1.54) | < 0.0001 |
 Minor axis length (cm), mean (SD) | 17.24 (2.11) | 18.90 (1.79) | < 0.0001 |
 Area (cm2), mean (SD) | 254.81 (60.72) | 296.58 (48.07) | < 0.0001 |
 Thickness (cm), mean (SD) | 2.50 (1.86) | 2.81 (3.42) | 0.47 |
Newborns | |||
 Female, N (%) | 52 (60.47) | 45 (56.96) | 0.75 |
 Gestational weeks (w), mean (SD) | 38.02 (0.97) | 38.04 (0.97) | 0.92 |
 Birth weight (g), mean (SD) | 2317.27 (136.27) | 3122.41 (349.60) | < 0.0001 |
 Length (cm), mean (SD) | 47.01 (1.48) | 49.27 (1.42) | < 0.0001 |
 Head circumference (cm), mean (SD) | 31.36 (1.33) | 33.48 (1.20) | < 0.0001 |