Tsarna, ErmioniReedijk, MarijeBirks, Laura Ellen, 1983-Guxens Junyent, MònicaBallester Díez, FerranHa, MinaJiménez-Zabala, AnaKheifets, LeekaLertxundi, AitanaLim, HyungryulOlsen, JørnGonzález-Safont, LlúciaSudan, MadhuriCardis, ElisabethVrijheid, MartineVrijkotte, TanjaHuss, AnkeVermeulen, Roel2020-01-142020-01-142019Tsarna E, Reedijk M, Birks LE, Guxens M, Ballester F, Ha M et al . Associations of maternal cell-phone use during pregnancy with pregnancy duration and fetal growth in 4 birth cohorts. Am J Epidemiol. 2019;188(7):1270-80. DOI: 10.1093/aje/kwz0920002-9262http://hdl.handle.net/10230/43269Results from studies evaluating potential effects of prenatal exposure to radio-frequency electromagnetic fields from cell phones on birth outcomes have been inconsistent. Using data on 55,507 pregnant women and their children from Denmark (1996-2002), the Netherlands (2003-2004), Spain (2003-2008), and South Korea (2006-2011), we explored whether maternal cell-phone use was associated with pregnancy duration and fetal growth. On the basis of self-reported number of cell-phone calls per day, exposure was grouped as none, low (referent), intermediate, or high. We examined pregnancy duration (gestational age at birth, preterm/postterm birth), fetal growth (birth weight ratio, small/large size for gestational age), and birth weight variables (birth weight, low/high birth weight) and meta-analyzed cohort-specific estimates. The intermediate exposure group had a higher risk of giving birth at a lower gestational age (hazard ratio = 1.04, 95% confidence interval: 1.01, 1.07), and exposure-response relationships were found for shorter pregnancy duration (P < 0.001) and preterm birth (P = 0.003). We observed no association with fetal growth or birth weight. Maternal cell-phone use during pregnancy may be associated with shorter pregnancy duration and increased risk of preterm birth, but these results should be interpreted with caution, since they may reflect stress during pregnancy or other residual confounding rather than a direct effect of cell-phone exposure.application/pdfeng© The Author(s) 2019. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journalpermissions@oup.com.info:eu-repo/semantics/articlehttp://dx.doi.org/10.1093/aje/kwz092Birth outcomesCell phonesExposurePreterm birthRadio-frequency electromagnetic fieldsinfo:eu-repo/semantics/openAccess