Skip to main content

Table 2 Distribution of selected characteristics of the study population by cooking fuel types

From: Exposure to cooking fuels and birth weight in Lanzhou, China: a birth cohort study

Characteristic

Gas

Coal

Biomass

Electromagnetic

Other

P*

N (%)

N (%)

N (%)

N (%)

N (%)

Birth weight

      

 LBW

371(4.7)

70(19.6)

42(35.0)

53(10.9)

114(11.1)

 

 NBW

6965(88.1)

270(75.4)

73(60.8)

408(83.8)

865(84.6)

<0.001

 Macrosomia

571(7.2)

18(5.0)

5(4.2)

26 (5.3)

44(4.3)

 

Birth weight

      

 SGA

509(6.4)

55(15.4)

22(18.4)

56(11.5)

114(10.2)

 

 AGA

6232(78.8)

264(73.7)

88(73.3)

377(77.4)

814(79.6)

<0.001

 LGA

1166(14.8)

39(10.9)

10(8.3)

54(11.1)

105(10.2)

 

Preterm

      

 No

7334(92.8)

267(74.6)

78(65.0)

417(85.6)

889(86.9)

 

 Yes

573(7.2)

91(25.4)

42(35.0)

70(14.4)

134(13.1)

<0.001

Maternal age (years)

      

 <25

1040(13.2)

136(38.0)

42(35.0)

226(27.9)

1580(22.1)

 

 25–29

3939(49.8)

108(30.2)

42(35.0)

438(43.1)

4737(42.8)

<0.001

 ≥30

2928(37.0)

114(31.8)

36(30.0)

359(29.0)

3578(35.1)

 

Highest education level

      

 High school or less

2706(34.2)

302(84.4)

108(90.0)

277(56.9)

473(46.2)

 

 College or above

5111(64.7)

55(15.4)

10(8.3)

205(42.1)

466(45.6)

<0.001

 Missing

90(1.1)

1(0.3)

2(1.7)

5(1.0)

84(8.2)

 

Family income (RMB per capita)

      

 <3000

3788(47.9)

264(73.7)

99(82.5)

330(67.8)

495(48.4)

 

 ≥3,000

3454(43.7)

58(16.2)

5(4.2)

137(28.1)

318(31.1)

<0.001

 Missing

665(8.4)

36(10.1)

16(13.3)

20(4.1)

210(20.5)

 

Maternal pre-pregnancy BMI (kg/m2)

      

 ≤18.5

1640(20.7)

63(17.6)

16(13.2)

93(19.1)

208(20.3)

 

 18.6–23.9

5276(66.7)

228(63.7)

67(55.8)

336(69.0)

593(58.0)

 

 ≥24

863(10.9)

36(10.0)

24(20.0)

49(10.1)

71(6.9)

<0.001

 Missing

128(1.7)

31(8.7)

13(10.8)

9(1.8)

151(14.8)

 

Maternal weight gain during pregnancy (kg)

      

 <15

2262(28.6)

158(44.1)

55(45.8)

204(41.9)

311(30.5)

 

 15–18.5

2573(32.6)

71(19.8)

20(16.7)

138(28.3)

248(24.2)

 

 >18.5

2910(36.9)

89(24.9)

25(20.8)

131(26.9)

298(29.1)

<0.001

 Missing

162(2.9)

40(11.2)

20(16.7)

14(2.9)

166(16.2)

 

Vitamin supplement during pregnancy

      

 No

963(12.2)

117(32.7)

49(40.8)

82(16.8)

255(24.9)

 

 Yes

6920(87.5)

239(66.8)

71(59.2)

403(82.8)

683 (66.8)

<0.001

 Missing

24(0.3)

2(0.5)

0(0.0)

2(0.4)

85(8.3)

 

Smoking (Active and passive)

      

 No

6416(81.1)

259(72.3)

91(75.8)

257(73.3)

844(82.5)

 

 Yes

1491(18.9)

99(27.7)

29(24.2)

130(26.7)

179(17.5)

<0.001

Alcohol during pregnancy

      

 No

7871(99.6)

357(99.7)

120(100.0)

487(100.0)

951(93.0)

 

 Yes

18(0.2)

0(0.0)

0(0.0)

0(0.0)

2(0.2)

0.697

 Missing

18(0.2)

1(0.3)

0(0.0)

0(0.0)

70(6.8)

 

Gestational Diabetes

      

 No

7828(99.0)

351(99.7)

118(98.3)

484(99.4)

1013(99.0)

 

 Yes

79(1.0)

1(0.3)

2(1.7)

3(0.6)

10(1.0)

0.539

Preeclampsia

      

 No

7710(97.5)

316(88.3)

101 (84.2)

464(95.3)

983(96.1)

 

 Yes

197(2.5)

42(11.7)

19(15.8)

23(4.7)

321(3.9)

<0.001

Parity

      

 Primiparous

5960(75.4)

186(52.0)

52(43.3)

339(69.6)

688(67.3)

 

 Multiparous

1947(24.6)

172(48.0)

68(56.7)

148(30.4)

335(32.7)

<0.001

Caesarean section

      

 No

4921(62.3)

194(54.2)

54(45.0)

307(63.0)

592(57.9)

 

 Yes

2927(37.0)

160(44.7)

65(54.2)

178(36.6)

417(40.8)

<0.001

 Missing

59(0.7)

4(1.1)

1(0.8)

2(0.4)

14(1.3)

 

Gender

      

 Boy

4162(52.6)

203(56.7)

69(56.7)

257 (57.5)

512(52.8)

 

 Girl

3732(47.2)

155(43.3)

51(43.3)

226(42.5)

509(46.4)

0.190

 Missing

13(0.2)

0(0.0)

0(0.0)

4(0.0)

2(0.8)

 

Ventilation

      

 No

751(9.5)

234(65.4)

98(81.7)

222(45.6)

713(69.7)

 

 Yes

7156(90.5)

124(34.6)

22(18.3)

265(54.4)

310(30.3)

<0.001

  1. *The analysis did not account for missing data