| Variables | Total sample (n = 283) | 1st trimester (n = 24) | 2nd trimester (n = 106) | 3rd trimester (n = 153) | p |
| Age (years)—mean ± SD | 27.7 ± 6.3 | 31.9 ± 6.7b | 27.3 ± 6.3a | 27.3 ± 6.0a | 0.002 |
| Skin color—n (%) |
|
|
|
| 0.595 |
| White | 180 (63.6) | 17 (70.8) | 67 (63.2) | 96 (62.7) |
|
| Black | 44 (15.5) | 2 (8.3) | 14 (13.2) | 28 (18.3) |
|
| Mixed | 59 (20.8) | 5 (20.8) | 25 (23.6) | 29 (19.0) |
|
| Marital status—n (%) |
|
|
|
| 1.000 |
| With partner | 280 (98.9) | 24 (100) | 105 (90.1) | 151 (98.7) |
|
| Without partner | 3 (1.1) | 0 (0.0) | 1 (0.9) | 2 (1.3) |
|
| Years of schooling—n (%) |
|
|
|
| 0.117 |
| <8 | 85 (30.1) | 7 (30.4) | 27 (25.5) | 51 (33.3) |
|
| 8 - 12 | 132 (46.8) | 7 (30.4) | 58 (54.7) | 67 (43.8) |
|
| >12 | 65 (23.0) | 9 (39.1) | 21 (19.8) | 35 (22.9) |
|
| Income—n (%) |
|
|
|
| 0.509 |
| Up to 1 m.w. | 45 (15.9) | 6 (25.0) | 19 (17.9) | 20 (13.1) |
|
| From 1 to 5 m.w. | 221 (78.1) | 17 (70.8) | 82 (77.4) | 122 (79.7) |
|
| >5 m.w. | 17 (6.0) | 1 (4.2) | 5 (4.7) | 11 (7.2) |
|
| N. of pregnancies—md (P25 - P75) | 2 (1 - 3) | 2.5 (1 - 4) | 2 (1 - 3) | 2 (1 - 3) | 0.680 |
| Abortion—n (%) | 57 (20.1) | 7 (29.2) | 18 (17.0) | 32 (20.9) | 0.381 |
| GA (week)—mean ± SD | 24.9 ± 8.5 | 10.1 ±1.6 | 18.8 ± 3.5 | 31.5 ±4.5 | <0.001 |
| Age at the beginning of sexual life (years)—mean ± SD | 16.0 ± 2.2 | 16.7 ±2.9 | 15.9 ± 2.2 | 15.9 ±2.1 | 0.220 |
| N. of partners in life—md (P25 - P75) | 4 (2 - 6) | 4 (2.5-8) | 4 (2 - 6) | 4 (2 - 6) | 0.782 |
| N. of partners in the past year—md (P25 - P75) | 1 (1 - 1) | 1 (1 - 1) | 1 (1 - 1) | 1 (1 - 1) | 0.120 |
| N. sexual intercourses in the past month—md (P25 - P75) | 5 (2 - 12) | 8 (4 - 12) | 8 (2 - 13) | 4 (2 - 10) | 0.001 |