Adjusted* OR for preterm birth according to number of medium (11–20 kg) and heavy (>20 kg) loads lifted per day at work during pregnancy
| Medium loads/day† | Heavy loads/day‡ | |||||
|---|---|---|---|---|---|---|
| None | 1–10 | >10 | ||||
| Adjusted OR | 95% CI | Adjusted OR | 95% CI | Adjusted OR | 95% CI | |
| None | 1 | 0.77 | (0.53 to 1.13) | 2.03 | (1.14 to 3.62) | |
| 1–10 | 1.07 | (0.95 to 1.20) | 1.19 | (1.04 to 1.36) | 1.38 | (0.70 to 2.72) |
| >10 | 1.30 | (1.00 to 1.69) | 0.75 | (0.49 to 1.13) | 1.36 | (1.02 to 1.82) |
62 803 women in the Danish National Birth Cohort, 1996–2002.
*Adjusted for maternal age, parity, cervical cone biopsy, IVF/ICSI treatment and smoking.
†Mean number of loads: 0, 4 and 35 loads/day, respectively.
‡Mean number of loads: 0, 4 and 33 loads/day, respectively.
ICSI, intra-cytoplasmic sperm injection; IVF, in vitro fertilisation.