Environment/Climate Change
Association between Climatic Factors and Pregnancy Loss Stefania Papatheodorou* Stefania Papatheodorou Aashna Shah Veronica Wang Marc Weisskopf Petros Koutrakis Souzana Achilleos
Background: Ambient climatic factors have been linked to multiple adverse pregnancy outcomes. However, only a few studies examined exposure to climatic factors and the risk of pregnancy loss. This study aims to examine the effects of climatic factors on pregnancy loss in Nicosia, Cyprus, an area that is highly affected by climate change.
Methods: Birth registry data for Nicosia, Cyprus from 2014-2019, were linked with daily meteorological and traffic pollution data (minimum and maximum temperature, ˚C; relative humidity, %; and NO2). Additional climactic variables (mean weekly temperature, standard deviation of the mean weekly temperature, heat index) were computed. We used a novel variation of time-series design and distributed lag models to explore the association between climatic factors and weekly live-birth identified conceptions (LBIC), to indirectly estimate pregnancy losses.
Results: In Nicosia (26,530 live births), an association between exposure to higher temperature and pregnancy loss was found between weeks 0-9, with the strongest association in weeks 0-1 weeks. Specifically, per 5 ˚C increase in mean temperature in week 0-1 we observed a lower rate of LBIC (Rate Ratio [RR]= 0.96 (95% confidence interval [CI]: 0.94 –0.98); the results for all other temperature-related and climatic exposures were similar. Furthermore, we found that temperature variability may have an impact in the later weeks of pregnancy. There is an association for weeks 20-35, with the strongest estimate in week 26 (RR= 0.93 (95% CI: 0.86 –0.99 per 5˚C increase in the standard deviation of the mean temperature).
Conclusion: Using the weekly conceptions ending in a live birth, we analyzed the association between climatic factors and pregnancy loss. The results show that exposure to higher temperatures and humidity is associated with pregnancy loss very early in pregnancy while temperature variability may have an effect between weeks 20-35.
