Gisselmann Marit Dahlén, Hemström Orjan
Centre for Health Equity Studies, CHESS, Stockholm, Sweden.
Soc Sci Med. 2008 Mar;66(6):1297-309. doi: 10.1016/j.socscimed.2007.11.036. Epub 2008 Jan 16.
The aims of this study were to examine the association between maternal working conditions and birth outcomes, and to determine the extent to which these contributed to class inequalities in six birth outcomes. We used an existing job exposure matrix developed from survey data collected in 1977 and 1979 to apply occupational-level information on working conditions to the national Swedish Registry, including approximately 280,000 mothers and 360,000 births during the period 1980--1985. Data were analysed using multivariate logistic regressions. Low levels of job control, high levels of physical demands and job hazards were more common in manual compared to non-manual classes. The self-employed had intermediate levels of such exposures. Job exposures, particularly low levels of job control, were generally and significantly associated with higher risks for low birthweight, very low birthweight, small for gestational age, all preterm, very preterm and extremely preterm births, but not with mortality. Compared to middle non-manuals (the reference group), lower non-manual and manual classes had higher risks for all birth outcomes, and these risks were nearly all significant. The highest odds ratios were found for skilled and unskilled manual workers in the manufacturing sector, with ratios between 1.35 and 2.66 (all significant). Job control explained a considerable proportion of inequalities in all birth outcomes. Job hazards contributed particularly to very low birthweight and extremely preterm birth, and physical demands to low birthweight and all preterm births. In conclusion, class differences in maternal working conditions clearly contributed to class differences in low birthweight (explained fraction 14-38%), all preterm births (20-46%), very (14-46%) and extremely (12-100%) preterm births. For very low birthweight and small for gestational age, there was a similar contribution in the manufacturing sector only. For all birth outcomes, class differences could still be detected after working conditions were taken into consideration.
本研究的目的是检验母亲工作条件与出生结局之间的关联，并确定这些因素在六种出生结局的阶层不平等中所起的作用程度。我们使用了一个现有的工作暴露矩阵，该矩阵是根据1977年和1979年收集的调查数据开发的，将工作条件的职业层面信息应用于瑞典国家登记处，其中包括1980年至1985年期间约280,000名母亲和360,000例分娩。数据采用多变量逻辑回归进行分析。与非体力劳动阶层相比，体力劳动阶层的工作控制水平较低、体力要求和工作危害程度较高的情况更为常见。个体经营者的此类暴露水平处于中等。工作暴露，尤其是工作控制水平较低，通常与低出生体重、极低出生体重、小于胎龄儿、所有早产、极早产和超早产的较高风险显著相关，但与死亡率无关。与中层非体力劳动者（参照组）相比，下层非体力劳动者和体力劳动者阶层在所有出生结局方面的风险更高，而且这些风险几乎均具有显著性。制造业中熟练和非熟练体力劳动者的比值比最高，在1.35至2.66之间（均具有显著性）。工作控制解释了所有出生结局不平等中的相当一部分。工作危害尤其导致极低出生体重和极早产，体力要求导致低出生体重和所有早产。总之，母亲工作条件的阶层差异显然导致了低出生体重（解释比例为14 - 38%）、所有早产（20 - 46%）、极早产（14 - 46%）和超早产（12 - 100%）的阶层差异。对于极低出生体重和小于胎龄儿，仅在制造业中有类似的作用。对于所有出生结局，在考虑工作条件后仍可检测到阶层差异。
