Association Between Meteorological Factors and Pregnancy Complications: Modeling, Analysis, and Evaluation

ISEE-143 Objective: Preeclampsia, preterm labor, preterm premature rupture of membrane (PPROM), and abruptio placenta are important causes of perinatal mortality and morbidity. Meteorological factors and seasonal changes could be proposed as some of the etiologic factors of considered outcomes. There are physiologic and epidemiologic evidences that natural phenomena such as weather conditions and sun and/or lunar cycles influence human body and its physiologic processes. The aim of this presentation was to analyze and evaluate possible effects of some meteorological parameters (in particular, heat effect) and natural cycles on pregnancy complications. Material and Methods: The data include all daily birth records for 1999 year registered at a medical center serving the entire population of Southern Israel. Dependent variables are daily numbers of above-named outcomes. Meteorological variables are daily maximum temperature and humidity, dichotomous variables “Hamsin” (the scorching hot, dry desert wind that blows from the Arabian Desert) and wind from Mediterranean Sea (increasing humidity). We used daily birth number as latent variable. Year, season, week, and lunar cycles were used in trigonometric form. Generalized linear Poisson regression models based on special time-series technique were built for analysis and evaluation of meteorological effects. To assess possible delayed weather effects, we performed 1- and 2-day lag analysis. Results: All dependent variables show significant cyclic patterns. The following statistically significant effects were found: for preeclampsia, direct effect of temperature and Mediterranean Sea wind; for preterm labor, direct and indirect (via seasonal factors) effect of humidity and indirect effect of Mediterranean Sea wind; for PPROM, indirect effect of Hamsin; and for abruptio placenta, direct effect of humidity. For 1- and 2-day lags the similar effects were recognized. Conclusions: Despite the relatively short study period, biologically obtained effects of the meteorological parameters are plausible. Obtained results were used for quantitative and qualitative evaluation of meteorological effects on pregnancy complications.