Table 3 Estimated risks of some work characteristics with sPTB in the EMIP study.

From: Maternal Work and Spontaneous Preterm Birth: A Multicenter Observational Study in Brazil

Characteristics of paid work

sPTB

Term birth

OR

95% CI

N (%)

N (%)

Period of pregnancy when women worked (a)

Never worked

825 (64.8)

644 (56.7)

Ref.

 

Without paid work during pregnancy or worked until 7th month

298 (23.4)

165 (14.5)

1.41

[1.16–1.72]

Worked until 8–9th month

150 (11.8)

326 (28.7)

0.36

[0.27–0.48]

Intense physical effort (b)

Without work/No intense work

1,043 (86.1)

899 (82.2)

Ref.

 

Yes/Sometimes

169 (13.9)

195 (17.8)

0.75

[0.55–1.02]

Standing required (c)

Without work/No or Sometimes

1,004 (82.8)

849 (77.7)

Ref.

 

Yes

208 (17.2)

244 (22.3)

0.72

[0.59–0.88]

Working hours (d)

Without work/Up to 8 hours/day

1,097 (90.7)

965 (88.4)

Ref.

 

More than 8 hours/day

112 (9.3)

127 (11.6)

0.78

[0.53–1.13]

Working the night shift (e)

Without work/No/Sometimes

1,150 (95.3)

1,014 (92.9)

Ref..

 

Yes

57 (4.7)

77 (7.1)

0.65

[0.42–1.01]

Household work (f)

Not or Yes, aided

660 (51.6)

514 (45.3)

Ref.

 

Yes, unaided

620 (48.4)

621 (54.7)

0.78

[0.64–0.94]

Level of work (g)

No work or not intense

1,024 (85.3)

888 (81.8)

Ref.

 

Intense

176 (14.7)

198 (18.2)

0.77

[0.59–1.00]

  1. Missing information for a) 8; b) 110; c) 111; d) 115; e) 118; f) 1; g) 130.
  2. Level of work defined as having two or more of the following: work with intense physical effort; standing; more than 8 h/day; at night.