1. . Methods : Conclusions: Examining the Relationship Between Atmospheric Pressure Changes and the Spontaneous Rupture of the Membranes Tamas Ungar, MD; Sarab Lalri, MD; Ebikaboere Youkedebah, MD; Maureen Grissom, PhD tungar12@NSHS.edutungar12@NSHS.edu, ebiks21@gmail.com, drlalri@shaw.ca, Mgrissom@nshs.edu.ebiks21@gmail.comdrlalri@shaw.caMgrissom@nshs.edu Hofstra University North Shore-LIJ Health System, Southside Hospital Family Medicine Residency Program Bibliography: 1.USA Today. Understanding Air Pressure. Retrieved on 2008-05-25 2.Osamu A. et al, Spontaneous delivery is related to barometric pressure, Archives of Gynecology and Obstetrics (2007) 275 249-254 3.Emmett H, et. Al., Meteorological factors and timing of the initiating event of human parturition, International Journal of Biometeorology (2011) 55; 265-272 4.Cunningham, F (2014). Williams Obstetrics. New York: McGraw-Hill Education. pp. Chapter 23: Abnormal Labor.  Graph 1: Most Deliveries occurred at times of low dP/dt, with a negative correlational coefficient (r) of -0.91.  A similar trend was seen in both PROM and term pregnancy SROM cases with r vales - 0.93 and -0.89 respectively.  Our analysis indicates a strong negative relationship between the number of deliveries and change in atmospheric pressure.  The direction of pressure change (rising or falling) seemed to have little effect on this negative correlation.  Our findings seem to counter the results of research that indicate increased number of deliveries with greater change in atmospheric pressure.  There seems to be minimal association with atmospheric pressure change and the gestational age at the time of delivery.  Our findings do not indicate causation but merely correlation. Introduction : Results:  Family medicine residents frequently hear attending physicians and nurses in the maternity ward speak anecdotally about an increase in deliveries with stormy weather.  Meteorologists make use of barometric pressure and the change of pressure over time (dP/dt) in forecasting stormy weather 1  Research in the field of Bio-Meteorology has shown that Spontaneous Rupture of Membranes (SROM) increase on days with a greater dP/dt. 2  Barometric pressure (BP) changes were also associated with slightly increased prediction of the timing of deliveries. 3  Established risk factors for Premature Rupture of Membranes (PROM) include infections, cigarette smoking, illicit drug use, polihydraminos, multiple gestation, and cervical insufficiency. 4 Hypothesis :  Atmospheric pressure changes correlate with the number of SROM and PROM Null Hypothesis:  Atmospheric pressure changes do not correlate with rates of SROM and PROM Potential Implications:  Disaster preparedness (i.e. hospital staffing during stormy weather)  Air travel recommendations (i.e. fluctuations in cabin pressure and pregnancy)  Expanding the field of bio-meteorology  A chart review was done on fifty patients admitted for PROM and SROM, spanning a period of 8 moths from June 2014 to January 2015.  The dP/dT was calculated in the hours preceding the time of membrane rupture, using detailed local data provided by the National Weather Service.  A correlational analysis was done of the dP/dt and the number of admissions for PROM and SROM. Maternal Variables like age, gravity and parity were also analyzed. Exclusion Criteria :  Presence of UTI, PID, Chorioamnionitis, multiple pregnancies, smoking history  Figure 1: Events of PROM (shown in yellow) on the Pressure-time curve from Sept (Courtesy: www.weathersource.com)  Graph 2: Considering the direction of dP/dt (rise or fall), most deliveries still occurred at times of lower magnitude pressure changes.  Graph 3: Examining gestational age of deliveries in relation to dP/dt. The plot shows a weak relationship. 14 th to 30 th, 2014. Precipitation is shown in orange.