Table 1.
Percent distribution of low birth weight and small for gestational age by maternal characteristics and p value of chi square.
| Characteristic Risk factors | Total N (%) | Control N (%) | Low birth weight N (%) | Small for gestation age N (%) | |
|---|---|---|---|---|---|
| Maternal age | |||||
| <20 years | 17 (2.5) | 10 (1.8) | 1 (1.7) | 7 (7.3) a | |
| 20–29 years | 402 (58.9) | 330 (60.1) | 29 (49.2) | 51 (53.1) | |
| ≥30 years | 263 (38.6) | 209 (38.1) | 29 (49.2) | 38 (39.6) | |
| Marital status | |||||
| Married | 532 (78.0) | 439 (80.0) | 40 (67.8) a | 66 (68.8) a | |
| Not married | 150 (22.0) | 110 (20.0) | 19 (32.2) | 30 (31.2) | |
| Maternal smoking | |||||
| Non-smoker | 611 (89.6) | 491 (89.4) | 53 (89.8) | 86 (89.6) | |
| Smoker (<1 cig/day) | 71 (10.4) | 58 (10.6) | 6 (10.2) | 10 (10.4) | |
| Paternal smoking | |||||
| No | 327 (48.3) | 264 (48.4) | 26 (44.8) | 44 (46.3) | |
| Yes (<1 cig/day) | 350 (51.7) | 282 (51.6) | 32 (55.2) | 51 (53.7) | |
| Alcohol consumption | |||||
| No | 640 (93.8) | 516 (94.0) | 55 (93.2) | 88 (91.7) | |
| Yes (<1 alc unit/day) | 42 (6.2) | 33 (6.0) | 4 (6.8) | 8 (8.3) | |
| Blood pressure | |||||
| <140/80 mm/Hg | 581 (85.2) | 470 (85.6) | 49 (83.1) | 78 (81.3) | |
| ≥140 or ≥90 mm/Hg | 101 (14.8) | 79 (14.4) | 10 (16.9) | 18 (18.7) | |
| Ethnic group | |||||
| Lithuanian | 660 (96.8) | 531 (96.7) | 57 (96.6) | 92 (95.8) | |
| Other | 22 (3.2) | 18 (3.3) | 2 (3.4) | 4 (4.2) | |
| Maternal education | |||||
| primary school | 58 (8.5) | 43 (7.8) | 9 (15.2) | 11 (11.4) | |
| secondary school | 296 (43.4) | 242 (44.1) | 23 (39.0) | 38 (39.6) | |
| university degree | 328 (48.1) | 264 (48.1) | 27 (45.8) | 47 (49.0) | |
| Parity | |||||
| No child | 319 (46.8) | 249 (45.4) | 26 (44.1) | 54 (56.2) a | |
| ≥ child | 363 (53.2) | 300 (54.6) | 33 (55.9) | 42 (43.7) | |
| Body mass index | |||||
| <25 Underweight and normal | 238 (35.0) | 169 (30.8) | 33 (55.9) a | 50 (52.1) a | |
| 25–30 Overweight | 308 (45.1) | 256 (46.6) | 20 (33.9) | 37 (38.5) | |
| >30 Obesity | 136 (19.9) | 124 (22.6) | 6 (10.2) | 9 (9.4) | |
| Hazard work exposure b | |||||
| No | 608 (89.1) | 489 (89.1) | 51 (83.6) | 87 (90.6) | |
| Yes | 74 (10.9) | 60 (10.9) | 10 (16.4) | 9 (9.4) | |
| Maternal disease c | |||||
| No | 461 (67.6) | 364 (66.3) | 37 (62.7) | 76 (79.2) a | |
| Yes | 221 (32.4) | 185 (33.7) | 22 (37.3) | 20 (20.8) | |
| Premature baby | |||||
| No | 654 (95.9) | 508 (92.5) | 53 (89.8)a | 93 (96.9) | |
| Yes | 28 (4.1) | 41 (7.5) | 6 (10.2) | 3 (3.1) | |
| THM exposure area | |||||
| Low level | 330 (48.4) | 279 (50.8) | 26 (44.1) | 44 (45.8) | |
| High level | 352 (51.6) | 270 (49.2) | 33 (55.9) | 52 (54.2) | |
| Infant gender | |||||
| Male | 364 (53.4) | 297 (54.1) | 27 (45.8) | 49 (51.0) | |
| Female | 318 (46.6) | 252 (45.9) | 32 (54.2) | 47 (49.0) | |
| Socioeconomic status d | |||||
| Low | 255 (37.4) | 202 (36.8) | 20 (33.9) | 39 (40.6) | |
| Medium | 321 (47.1) | 262 (47.7) | 29 (49.2) | 42 (43.8) | |
| High | 106 (15.5) | 85 (15.5) | 10 (16.9) | 15 (15.6) | |
| GSTT1 | |||||
| GSTT1–1 | 570 (83.6) | 459 (83.6) | 47 (79.7) | 81 (84.4) | |
| GSTT1–0 | 112 (16.4) | 90 (16.4) | 12 (20.3) | 15 (15.6) | |
| GSTM1 | |||||
| GSTM1–1 | 350 (51.3) | 286 (52.1) | 25 (42.4) | 49 (51.0) | |
| GSTM1–0 | 332 (48.7) | 263 (47.9) | 34 (57.6) | 47 (49.0) | |
a p < 0.05; b Hazard work exposure (chemicals, dust, noise, hard work and other, this was a subjective assessment of each participant); c Maternal disease: diabetes, renal and urinary, sexual, respiratory, heart and vascular, congenital heart disease; d Socioeconomic status—Low (housekeeper, workwoman, student, jobless); Medium (salaried, farmer); High (manager, businesswoman).