Air pollution can raise the risk of miscarriage among women finds study

By Dr. Ananya Mandal, MDJan 13 2019

A new study has shown that similar to smoking, exposure to air pollution can also raise the risk of miscarriages among women. The team of researchers from University of Utah have found that higher levels of gases such as nitrogen dioxide that comes from burning of the fossil fuels such as diesel are linked to a 16 percent risk of a miscarriage. The study results appeared in an article published in the latest issue of the journal Fertility and Sterility.

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There have been long term studies that have revealed that air pollution can harm the unborn babies in multiple ways such as causing low birth weight, organ damage and preterm births. This is the first study that looks at the effects of a short term exposure to air pollution. Dr Matthew Fuller, study leader, in a statement said that the effects of air pollution on unborn babies are “very upsetting”. He said the effects of air pollution on the foetuses are similar to the harm caused by tobacco smoke inhalation in terms of pregnancy loss that occurs within the first trimester or the first three months. Fuller had begun studying the effects of air pollution on pregnancy after a member of his own family had miscarried in 2016 due to exposure to a time with poor air quality.  He said in a statement, “That triggered the question in my mind and then I started noticing anecdotally that I was seeing spikes in miscarriage numbers in the emergency department during and after pollution spikes.”

According to researchers pregnant women should consider indoor air filter use and also avoid exerting themselves outdoors during days with poor air quality. The team looked at the effects of the air of Salt Lake City, US. The air levels of nitrogen dioxide there is similar to air in London and Paris, they explain. The team analyzed the details of over 1,300 women who miscarried between 2007 and 2015. The air pollution levels were compared with their pregnancies when they carried successfully till delivery. This means that each woman who miscarried and then had a successful pregnancy acted as her own control in the comparison.

They found that miscarriages were most associated with nitrogen dioxide levels within seven days of the miscarriage. The team believes that the air pollution could be causing inflammation and other changes in the foetus and placenta and that could be the reson behind the miscarriage.

Research analyst Claire Leiser, who was part of the study pointed out that their study looked at only the most severe cases during a small period of time of the study. A longer term study might reveal more she explained. Also many women who faced minor health problems during their pregnancy attributed to air pollution were missed out in this study. “These results are not the whole picture,” she said.

Source: https://www.fertstert.org/article/S0015-0282(18)32154-X/fulltext