Retraction Note to: Ambient air pollution and adverse birth outcomes: a systematic review and meta-analysis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Retraction Note to: J Zhejiang Univ-Sci B (Biomed & Biotechnol) 2019 20(3):238-252. https://doi.org/10.1631/jzus.B1800122. The authors have retracted this article (Guo et al., 2019) because some data from the original literature had not been converted to appropriate units in the paper, which resulted in deviation of the meta-analysis results. For example, for the forest plot used to examine associations between PM exposure and the risk of adverse birth outcomes, the estimates from Brauer et al. (2008), Pedersen et al. (2013), Zhao et al. (2015), and Hansen et al. (2006) were on the originally reported scales of 1 µg/m, 10 µg/m, 10 µg/m, and Inter Quartile Range, respectively. None of these estimates had been converted to 20 µg/m increase scale that was stated in the article. Similar problem exists in the analysis on associations between NO exposure and risk of adverse birth outcomes. Therefore, the results of the meta-analysis are misleading. All authors have agreed to this retraction and express their deepest apologies to the original authors, publishers, and readers.

Ambient air pollution and adverse birth outcomes: a systematic review and meta-analysis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Several reviews have assessed the relationship between exposure to ambient air pollution and adverse birth outcomes during pregnancy, but the results remain controversial. The objective of this study was to assess this correlation quantitatively and to explore sources of heterogeneity. We included all published case-control or cohort studies that evaluated the correlation between ambient air pollution and low birth weight (LBW), preterm birth (PTB), and small for gestational age (SGA). Analytical methods and inclusion criteria were provided on the PROSPERO website (CRD42018085816). We evaluated pooled effects and heterogeneity. Subgroup analyses (grouped by exposure period, study settings, study design, exposure types, data source, Newcastle-Ottawa quality score (NOS), and adjustment for smoking or meteorological factors) were also conducted and publication bias was examined. The risk of bias in systematic reviews (ROBIS) tool was used to evaluate the overall risk of bias in this review. Forty studies met the inclusion criteria. We observed pooled odds ratios (ORs) of 1.03-1.21 for LBW and 0.97-1.06 for PTB when mothers were exposed to CO, NO2, NOx, O3, PM2.5, PM10, or SO2 throughout their pregnancy. For SGA, the pooled estimate was 1.02 in relation to NO2 concentrations. Subgroup analysis and sensitivity analysis decreased the heterogeneity to some extent, such as the subgroups of continuous measures (OR=0.98 (0.97-0.99), I2=0.0%) and NOS>7 (OR=0.98 (0.97-0.99), I2=0.0%) in evaluating the association between PTB and NO2. This review was completed with a low risk of bias. High concentrations of air pollution were significantly related to the higher risk of adverse birth outcomes. However, the sources of heterogeneity among studies should be further explored.

Risk of congenital heart disease due to exposure to common electrical appliances during early pregnancy: A case-control study / 西安交通大学学报(医学版)

Objective: To compare the exposure of commonly used electrical appliances by mothers in early pregnancy so as to explore the association between electromagnetic exposure in daily life and congenital heart disease (CHD). Methods: We conducted a hospital-based case-control study. Totally 274 mothers in the case group and 548 mothers in the control group were interviewed through a face-to-face questionnaire. The multivariate logistic regression was applied to analyze the association between CHD and electromagnetic exposure. Results: After adjustment for the confounding factors, in early pregnancy, mothers' exposure to cell phones (OR=0.20, 95% CI: 0.07-0.58), induction cookers (OR=1.97, 95% CI: 1.31-2.96) and microwave ovens (OR=2.90, 95% CI: 1.41-5.97), and wearing radiation suits (OR=0.58, 95% CI: 0.39-0.86) were related to the occurrence of CHD. In the subgroup analysis, compared with the non-radiation suit, microwave oven exposure of the mothers in radiation suits did not significantly affect CHD in early pregnancy, but exposure to induction cookers could increase the risk of CHD in both subgroups. Conclusion: Mothers' exposure to microwave ovens and induction cookers in early pregnancy may increase the risk of CHD in the offspring. The exposure should be decreased and avoided as much as possible.