From: Exposure to cooking fuels and birth weight in Lanzhou, China: a birth cohort study
Characteristic | LBW | NBW | P | SGA | AGA | P |
---|---|---|---|---|---|---|
N (%) | N (%) | Â | N (%) | N (%) | ||
Maternal age (years) | Â | Â | Â | Â | Â | Â |
 <25 | 164(25.2) | 1344(15.7) |  | 161(21.6) | 1256(16.2) |  |
 25–29 | 227(34.9) | 4205(49.0) |  | 318(42.6) | 3765(48.4) |  |
 ≥30 | 259(39.9) | 3032(35.3) | <0.001 | 267(35.8) | 2754(35.4) | <0.001 |
Highest education level | Â | Â | Â | Â | Â | Â |
 High school or less | 414(63.7) | 3230(37.6) |  | 399(53.5) | 2972(38.2) |  |
 College or above | 219(33.7) | 5196(60.6) | <0.001 | 333(44.6) | 4656(59.9) | <0.001 |
 Missing | 17(2.6) | 155(1.8) |  | 14(1.9) | 147(1.9) |  |
Family income (RMB per capita) | Â | Â | Â | Â | Â | Â |
 <3000 | 436(67.1) | 4233(49.3) |  | 452(60.6) | 3879(49.9) |  |
 ≥3,000 | 154(23.7) | 3525(41.1) | <0.001 | 216(28.9) | 3164(40.7) | <0.001 |
 Missing | 60(9.2) | 823(9.6) |  | 78(10.5) | 732(9.4) |  |
Maternal pre-pregnancy BMI (kg/m2) | Â | Â | Â | Â | Â | Â |
 ≤18.5 | 135(20.8) | 1822(21.2) |  | 189(25.3) | 1670(21.5) |  |
 18.6–23.9 | 396(60.9) | 5645(65.8) |  | 445(59.7) | 5122(65.9) |  |
 ≥24 | 79(12.1) | 843(9.8) | 0.078 | 77(10.3) | 732(9.4) | 0.010 |
 Missing | 40(6.2) | 273(3.2) |  | 35(4.7) | 251(3.2) |  |
Maternal weight gain during pregnancy (kg) | Â | Â | Â | Â | Â | Â |
 <15 | 346(53.2) | 2541(29.6) |  | 313(42.0) | 2415(31.1) |  |
 15–18.5 | 132(20.3) | 2753(32.1) |  | 215(28.8) | 2468(31.7) |  |
 >18.5 | 108(16.6) | 2973(34.6) | <0.001 | 171(22.9) | 2590(33.3) | <0.001 |
 Missing | 64(9.9) | 314(3.7) |  | 47(6.3) | 302(3.9) |  |
Vitamin supplement during pregnancy | Â | Â | Â | Â | Â | Â |
 No | 150(23.1) | 1234(14.4) |  | 152(20.4) | 1124(14.5) |  |
 Yes | 486(74.8) | 7259(84.6) | <0.001 | 581(77.9) | 6564(84.4) | <0.001 |
 Missing | 14(2.1) | 90(1.0) |  | 13(1.7) | 87(1.1) |  |
Smoking (Active and passive) | Â | Â | Â | Â | Â | Â |
 No | 489(75.2) | 6923(80.7) |  | 560(75.1) | 6272(80.7) |  |
 Yes | 161(24.8) | 1658(19.3) | <0.001 | 186(24.9) | 1502(19.3) | <0.001 |
Alcohol during pregnancy | Â | Â | Â | Â | Â | Â |
 No | 641(98.6) | 8490(98.9) |  | 735(98.5) | 7693(98.9) |  |
 Yes | 2(0.3) | 17(0.2) | 0.882 | 2(0.3) | 15(0.2) | 0.989 |
 Missing | 7(1.1) | 74(0.9) |  | 9(1.2) | 67(0.9) |  |
Gestational Diabetes | Â | Â | Â | Â | Â | Â |
 No | 647(99.5) | 8513(99.2) |  | 743(99.6) | 7717(99.2) |  |
 Yes | 3(0.5) | 68(0.8) | 0.485 | 3(0.3) | 58(0.8) | 0.368 |
Preeclampsia | Â | Â | Â | Â | Â | Â |
 No | 539(82.9) | 8388(97.8) |  | 659(88.3) | 7582(97.5) |  |
 Yes | 111(17.1) | 193(2.2) | <0.001 | 87(11.7) | 193(2.5) | <0.001 |
Parity | Â | Â | Â | Â | Â | Â |
 Primiparous | 379(58.5) | 6375(74.3) |  | 518(69.4) | 5734(73.8) |  |
 Multiparous | 269(41.5) | 2208(25.7) | <0.001 | 228(30.6) | 2041(26.2) | 0.012 |
Caesarean section | Â | Â | Â | Â | Â | Â |
 No | 298(45.8) | 5473(63.8) |  | 400(53.6) | 4978(64.0) |  |
 Yes | 326(50.2) | 3058(35.6) | <0.001 | 335(44.9) | 2739(35.2) | <0.001 |
 Miss | 26(4.0) | 50(0.6) |  | 11(1.5) | 58(0.8) |  |
Gender | Â | Â | Â | Â | Â | Â |
 Boy | 326(50.2) | 4427(51.6) |  | 369(49.5) | 4067(52.3) |  |
 Girl | 322(49.5) | 4138(48.2) |  | 376(50.4) | 3693(47.5) |  |
 Missing | 2(0.3) | 16(0.2) | 0.498 | 1(0.1) | 15(0.2) | 0.133 |
Ventilation | Â | Â | Â | Â | Â | Â |
 No | 271(41.7) | 1646(19.2) |  | 249(33.4) | 1563(20.1) |  |
 Yes | 379(58.3) | 6935(80.8) | <0.001 | 497(66.6) | 6212(79.9) | <0.001 |