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Meta-Analysis
. 2011 Nov;118(12):1429-37.
doi: 10.1111/j.1471-0528.2011.03066.x. Epub 2011 Jul 27.

Shift work and pregnancy outcomes: a systematic review with meta-analysis of currently available epidemiological studies

M Bonzini  1 , K T Palmer, D Coggon, M Carugno, A Cromi, M M Ferrario
Affiliations
Meta-Analysis

Shift work and pregnancy outcomes: a systematic review with meta-analysis of currently available epidemiological studies

M Bonzini et al. BJOG. 2011 Nov.

Abstract

Background: Varying work schedules are suspected of increasing risks to pregnant women and to fetal wellbeing. In particular, maternal hormonal disturbance arising from sleep deprivation or circadian rhythm disruption might impair fetal growth or lead to complications of pregnancy. Two independent meta-analyses (from 2000 to 2007) reported a small adverse effect of shift work on the risk of preterm delivery (PTD). However, these reviews were based on few high-quality studies.

Objectives: To provide an updated review of the associations of shift work with PTD, low birthweight (LBW), small-for-gestational-age (SGA) infants and pre-eclampsia.

Search strategy and selection criteria: We conducted a systematic search of MEDLINE using combinations of keywords and MeSH terms.

Data collection and analysis: For each relevant paper we abstracted standard details, used to summarise design features and rate methodological quality. We calculated pooled estimates of relative risk (RR) in random-effect meta-analyses.

Main results: We retrieved 23 relevant studies. The pooled estimate of RR for PTD was 1.16 (95% CI 1.00-1.33, 16 studies), but when five reports of poorer methodological quality were excluded, the estimated RR decreased to 1.03 (95% CI 0.93-1.14). We also observed increased RRs for LBW (RR 1.27, 95% CI 0.93-1.74) and for SGA (RR 1.12, 95% CI 1.03-1.22), which varied little by study quality. Little evidence was found on pre-eclampsia.

Conclusions: These findings suggest that overall, any risk of PTD, LBW, or SGA arising from shift work in pregnancy is small.

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Figures

Figure 1
Figure 1
Studies investigating PTD risk and shift work exposure. Random effects meta-analysis.
Figure 2
Figure 2
Studies investigating the association between shift work exposure and the risk of delivering a SGA baby. Random effects meta-analysis.
See this image and copyright information in PMC

Comment in

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