Mocevic Emina, Svendsen Susanne Wulff, Jørgensen Kristian Tore, Frost Poul, Bonde Jens Peter
Department of Occupational and Environmental Medicine, Bispebjerg Hospital, University of Copenhagen, Copehagen, Denmark.
Danish Ramazzini Centre, University Department of Occupational Medicine, Herning Regional Hospital, Herning, Denmark.
PLoS One. 2014 Mar 10;9(3):e90550. doi: 10.1371/journal.pone.0090550. eCollection 2014.
We examined the association between occupational lifting during pregnancy and risk of fetal death and preterm birth using a job exposure matrix (JEM).
For 68,086 occupationally active women in the Danish National Birth Cohort, interview information on occupational lifting was collected around gestational week 16. We established a JEM based on information from women, who were still pregnant when interviewed. The JEM provided mean total loads lifted per day within homogeneous exposure groups as informed by job and industry codes. All women were assigned an exposure estimate from the JEM. We used Cox regression models with gestational age as underlying time variable and adjustment for covariates.
We observed 2,717 fetal deaths and 3,128 preterm births within the study cohort. No exposure-response relation was observed for fetal death, but for women with a prior fetal death, we found a hazard ratio (HR) of 2.87 (95% CI 1.37, 6.01) for stillbirth (fetal death ≥22 completed gestational weeks) among those who lifted >200 kg/day. For preterm birth, we found an exposure-response relation for primigravid women, reaching a HR of 1.43 (95% CI 1.13, 1.80) for total loads >200 kg per day. These findings correspond to an excess fraction of 11% for stillbirth and 10% for preterm birth.
We found an increased risk of stillbirth among women with a prior fetal death, who lifted >200 kg/day, and an exposure-response relationship between occupational lifting and preterm birth among primigravid women. The study adds to a large body of prospective studies on occupational lifting and adverse pregnancy outcomes by refined exposure assessment.
我们使用工作暴露矩阵（JEM）研究孕期职业性提举与胎儿死亡和早产风险之间的关联。
对于丹麦国家出生队列中的68,086名职业活跃女性，在妊娠第16周左右收集了有关职业性提举的访谈信息。我们根据访谈时仍怀孕的女性的信息建立了一个JEM。该JEM根据工作和行业代码提供了同质暴露组内每天提举的平均总负荷。所有女性都被赋予了来自JEM的暴露估计值。我们使用以胎龄为基础时间变量并对协变量进行调整的Cox回归模型。
在研究队列中，我们观察到2,717例胎儿死亡和3,128例早产。未观察到胎儿死亡的暴露-反应关系，但对于有过胎儿死亡史的女性，我们发现每天提举超过200千克的女性中，死产（胎儿死亡≥22个完整孕周）的风险比（HR）为2.87（95%CI 1.37, 6.01）。对于早产，我们发现初产妇存在暴露-反应关系，每天总负荷超过200千克时，HR达到1.43（95%CI 1.13, 1.80）。这些发现对应的死产超额比例为11%，早产超额比例为10%。
我们发现有过胎儿死亡史且每天提举超过200千克的女性死产风险增加，并且初产妇的职业性提举与早产之间存在暴露-反应关系。该研究通过精细的暴露评估，为大量关于职业性提举与不良妊娠结局的前瞻性研究增添了内容。
