Systematic review on adverse birth outcomes of climate change

Background: Climate change and global warming have significant effects on human health. This systematic review presents the effects of the climate changes on pregnancy outcomes. Materials and Methods: The search process was conducted in electronic databases including ISI Web of Knowledge, PubMed, Scopus, and Google Scholar using key words of "environmental temperature" "pregnancy" "low birth weight (LBW)" "pregnancy outcome," "climate change," "preterm birth (PTB)," and a combination of them. We did not consider any time limitation; English-language papers were included. The related papers were selected in three phases. After quality assessment, two reviewers extracted the data while the third reviewer checked their extracted data. Finally, 15 related articles were selected and included in the current study. Results: Approximately all studies have reported a significant relationship between exposure variable and intended outcomes including eclampsia, preeclampsia, cataract, LBW, PTB, hypertension, sex ratio and length of pregnancy. According to conducted studies, decrease in birth weight is more possible in cold months. Increase in temperature was followed by increase in PTB rate. According to most of the studies, eclampsia and preeclampsia were more prevalent in cold and humid seasons. Two spectrums of heat extent, different seasons of the year, sunlight intensity and season of fertilization were associated with higher rates of PTB, hypertension, eclampsia, preeclampsia, and cataract. Conclusion: Climate change has unfavorable effects on eclampsia, preeclampsia, PTB, and cataract. The findings of this review confirm the crucial importance of the adverse health effects of climate change especially in the perinatal period.