Occupational activity and risk of being small-for-gestational age at delivery
| First author (year) | Numbers in analysis | RR (95% CI) | Exposure | Higher potential for | Incomplete reporting | ||
|---|---|---|---|---|---|---|---|
| Comparison | Timing | Bias | Confounding | ||||
| h/d, hours per day; h/wk, hours per week; x/wk, times per week. | |||||||
| RR is used generically to encompass a variety of published effect measures (odds ratios, incidence density ratios, hazard ratios and so on). | |||||||
| Weekly working hours | |||||||
| Cohort studies | |||||||
| Pompeii LA (2005)38 | 1037 | 1.1 (0.7 to 1.7) | >46 vs 35–45 h/wk | Trimester 1 | No | No | No |
| Pompeii LA (2005)38 | 1037 | 1.0 (0.6 to 1.8) | >46 vs 35–45 h/wk | Trimester 2 | No | No | No |
| Tuntiseranee P (1998)52 | 886 | 2.1 (0.6 to 7.0) | ⩾61 vs ⩽50 h/wk | 15–28 weeks | No | Yes | No |
| Cross-sectional studies | |||||||
| Bodin L (1999)8 | 1685 | 1.1 (0.7 to 1.9) | ⩾36 vs 21–35 h/wk | Trimester 2 | No | No | No |
| Ceron-Mireles P (1996)11 | 2406 | 1.59 (1.14 to 2.22) | >50 vs 3–25 h/wk | Not stated | No | Yes | No |
| Fortier I (1995)13 | 1833 | 0.99 (0.7 to 1.39) | ⩾40 vs <30 h/wk | Not stated | No | No | No |
| Klebanoff MA (1990)20 | 989 | 0.9 (0.6 to 1.3) | Residents (>100 h) vs others | Any | No | No | No |
| Savitz DA (1996)46 | 589 | 0.8 (0.6 to 1.2) | ⩾40 vs no paid work | 5 months | No | No | No |
| Shift work | |||||||
| Cohort studies | |||||||
| Pompeii LA (2005)38 | 1796 | 1.3 (0.8 to 2.2) | Regular night work (yes vs no) | Trimester 1 | No | No | No |
| Pompeii LA (2005)38 | 1796 | 1.4 (0.9 to 2.4) | Regular night work (yes vs no) | Trimester 2 | No | No | No |
| Zhu JL (2004)56 | 35 662 | 1.07 (0.94 to 1.21) | Rotating shift work vs daytime work | Trimesters 1 and 2 | No | No | No |
| Cross-sectional studies | |||||||
| Bodin L (1999)8 | 1685 | 0.8 (0.4 to 1.8) | Night vs day | Trimester 2 | No | No | No |
| Fortier I (1995)13 | 4118 | 0.98 (0.75 to 1.27) | Shift work vs day only | Not stated | No | No | No |
| Hanke W (1999)14 | 1064 | 1.0 (0.19 to 3.26) | Shift work (yes vs no) | Not stated | No | No | No |
| Nurminen T (1989)34 | 738 | 1.5 (1.0 to 2.4) | Shift work (yes vs no) | Most of pregnancy | No | Yes | No |
| Lifting | |||||||
| Cohort studies | |||||||
| Ahlborg GJ (1990)5 | 3389 | 0.65 (0.24 to 1.77) | ⩾12 kg >50 x/wk vs none | Not stated | No | No | No |
| Magann EF (2005)26 | 485 | 0.81 (0.47 to 1.41) | ⩾4 vs <4 h/d | Trimester 1 | No | No | No |
| Pompeii LA (2005)38 | 1176 | 1.2 (0.7 to 2.0) | Lifting ⩾25 lbs⩾13 vs 0 x/wk | Trimester 1 | No | No | No |
| Pompeii LA (2005)38 | 1176 | 1.2 (0.6 to 2.2) | Lifting ⩾25 lbs⩾13 vs 0 x/wk | Trimester 2 | No | No | No |
| Tuntiseranee P (1998)52 | 1108 | 0.5 (0.1 to 1.7) | >12 kg, 1–10 x/d vs none | 15–28 weeks | No | Yes | No |
| Cross-sectional studies | |||||||
| Fortier I (1995)13 | 3078 | 1.03 (0.71 to 1.51) | ⩾10 kg vs none | Not stated | No | No | No |
| Standing | |||||||
| Cohort studies | |||||||
| Launer LJ (1990)23 | 5035 | 1.21 (1.02 to 1.44) | Standing vs sitting | Not stated | No | Yes | No |
| Magann EF (2005)26 | 318 | 0.59 (0.20 to 1.74) | Lifting ⩾11 kg >6 x/h | Trimester 1 | No | No | No |
| Pompeii LA (2005)38 | 977 | 1.1 (0.7 to 1.7) | >30 vs 6–15 h/wk | Trimester 1 | No | No | No |
| Pompeii LA (2005)38 | 977 | 1.0 (0.6 to 1.5) | >30 vs 6–15 h/wk | Trimester 2 | No | No | No |
| Tuntiseranee P (1998)52 | 1121 | 2.0 (0.7 to 5.4) | ⩾5 vs ⩽4 h/d | 15–28 weeks | No | Yes | No |
| Cross-sectional studies | |||||||
| Ceron-Mireles P (1996)11 | 2379 | 1.4 (1.03 to 1.91) | >7 vs ⩽7 h/d | Not stated | No | Yes | No |
| Fortier I (1995)13 | 3502 | 1.42 (1.02 to 1.95) | ⩾6 vs <3 h/d | Not stated | No | No | No |
| Hanke W (1999)14 | 1064 | 0.89 (0.48 to 1.62) | Mostly standing posture at work (yes vs no) | Not stated | No | No | No |
| Nurminen T (1989)35 | 676 | 1.0 (0.4 to 2.3) | Standing work vs sedentary | Trimester 3 | No | Yes | No |
| Physical activity | |||||||
| Cohort studies | |||||||
| Launer LJ (1990)23 | 5035 | 1.32 (1.12 to 1.56) | Manual vs office work | Not stated | No | Yes | No |
| Magann EF (1996)25 | 531 | 0.8 (0.42 to 1.45) | >2900 vs <2300 kcal/day energy expenditure | 16–18 weeks | No | Yes | No |
| Tuntiseranee P (1998)52 | 346 | 0.7 (0.20 to 3.2) | High vs low | 15–28 weeks | No | Yes | No |
| Cross-sectional studies | |||||||
| Ceron-Mireles P (1996)11 | 2379 | 1.4 (1.03 to 1.91) | >7 vs ⩽7 h/d | Not stated | No | Yes | No |
| Fortier I (1995)13 | 1829 | 0.87 (0.56 to 1.35) | Important vs none | Not stated | No | No | No |
| Hanke W (1999)14 | 1064 | 0.89 (0.48 to 1.62) | Mostly standing posture at work (yes vs no) | Not stated | No | No | No |
| Nurminen T (1989)35 | 524 | 2.4 (1.3 to 4.6) | Work with a moderate physical load vs sedentary | Trimester 3 | No | Yes | No |