Table 1 Statistical summary of baseline characteristics
Variables | SPB Group (n = 120) | Control Group (n = 120) | P |
|---|---|---|---|
Mean (SDa) | Mean (SDa) | ||
Age | 29.9 (4.3) | 29.9 (4.1) | – |
Body mass index | 20.8 (2.7) | 20.6 (3.2) | – |
Gravidity | 2.0 (1.1) | 2.0 (1.1) | – |
Parity | 0.5 (0.7) | 0.5 (0.7) | – |
Sampling gestational age (weeks) | 11.3 (0.64) | 11.3 (0.66) | 0.677 |
Race, n (%) |  |  | – |
 Han | 118 (98.3) | 118 (98.3) |  |
 Others | 2 (1.7) | 2 (1.7) |  |
Education, n (%) | Â | Â | 0.148b |
 Elementary school or lower | 2 (1.7) | 0 (0) |  |
 Junior high school | 12 (10.0) | 15 (12.5) |  |
 Senior high school | 11 (9.2) | 18 (15.0) |  |
 Undergraduate | 90 (75.0) | 78 (65.0) |  |
 Graduate or higher | 4 (3.3) | 9 (7.5) |  |
 Missing | 1 (0.8) | 0 (0) |  |
Monthly family income, n (%) | Â | Â | 0.060 |
 < 6000 | 12 (10) | 3 (2.5) |  |
 6000–14999 | 69 (57.5) | 81(67.5) |  |
 15,000–29999 | 26 (21.7) | 29 (24.2) |  |
 < 30,000 | 11 (9.2) | 7 (5.8) |  |
 Missing | 2 (1.7) | 0 (0) |  |
Passive smoking, n (%) |  |  |  > 0.999 |
 Yes | 52 (43.3) | 53 (44.2) |  |
 No | 67 (55.8) | 67 (55.8) |  |
 Missing | 1 (0.8) | 0 (0) |  |
Folate intake, n (%) | Â | Â | 0.749 |
 Yes | 79 (65.8) | 75 (62.5) |  |
 No | 40 (33.4) | 43 (35.8) |  |
 Missing | 1 (0.8) | 2 (1.7) |  |
Delivery mode, n (%) | Â | Â | 0.127 |
 Cesarean | 44 (36.7) | 32 (26.7) |  |
 Natural | 76 (63.3) | 88 (73.3) |  |
Fetus sex, n (%) | Â | Â | 0.014 |
 Male | 75 (62.5) | 55 (45.8) |  |
 Female | 45 (37.5) | 65 (54.2) |  |