Abstract
This study was undertaken to use the Arizona State birth certificate database for Phoenix metropolitan hospitals, in conjunction with National Weather Service records to determine whether there is a relationship between birth rate and meteorologic or lunar conditions. This study attempts to dispel or lend significance to beliefs among hospital staff that the phase of the moon and/or meteorologic conditions are related to birth rate.
Birth records were limited to spontaneous vaginal deliveries, 37 to 40 weeks' gestation, in Phoenix, between 1995 and 2000 (n
=
167,956). Daily birth counts were merged with daily surface weather statistics from the National Weather Service for Sky Harbor Airport, and records of lunar phase for the same period.
The analyses revealed no significant correlates of birth rate.
Although there exists a popular belief that the phase of the lunar cycle and weather conditions affect birth rate, no such evidence was found in this study.