Table 3 Association between outcome (congenital birth defect), exposure (household cooking fuel type usage) and all covariates 2017–2018 in Nepal

Household cooking fuel type usage

Cleaner fuel

Ref

Ref

Polluting fuel

1.58 (1.24–2.02)

< 0.001

1.49 (1.16–1.91)

0.002

Air ventilation

Yes

Reference

No

1.53 (0.99–2.36)

0.055

1.34 (0.86–2.07)

0.195

Maternal age

< 20

Ref

Ref

20–26

0.67 (0.47–0.96)

0.030

0.51 (0.34–0.75)

< 0.001

27–34

0.55 (0.36–0.85)

0.007

0.41 (0.25–0.65)

< 0.001

35<

0.96 (0.49–1.90)

0.909

0.60 (0.29–1.25)

0.170

Maternal education

No education

Ref

Ref

Basic education

1.08 (0.71–1.64)

0.728

1.28 (0.84–1.96)

0.249

Secondary and higher

1.18 (0.84–1.66)

0.337

2.00 (1.40–2.86)

< 0.001

Ethnicity

Advantaged

Ref

Ref

Disadvantaged

1.82 (1.41–2.34)

< 0.001

1.81 (1.39–2.35)

< 0.001

Household monthly income

Lowest

Ref

Ref

Lower

0.65 (0.42–1.01)

0.054

0.64 (0.42-1.00)

0.042

Higher

0.51 (0.38–0.68)

< 0.001

0.53 (0.39–0.71)

< 0.001

Highest

0.41 (0.29–0.57)

< 0.001

0.49 (0.35–0.68)

< 0.001

Sex of the child

Male

Ref

Ref

Female

1.45 (1.16–1.81)

0.001

1.47 (1.17–1.83)

< 0.001

Parity

0 previous births

Ref

Ref

1 previous birth

1.27 (0.98–1.64)

0.070

1.64 (1.24–2.18)

< 0.001

2 or more previous births

1.72 (1.30–2.30)

< 0.001

2.30 (1.66–3.20)

< 0.001

Single or multiple pregnancy

Single

Ref

Ref

Multiple

2.88 (1.42–5.84)

0.003

2.70 (1.32–5.52)

0.007