Lunar periodicity with reference to live births

Abstract

A half-million live births, occurring during 37 synodic lunar months and constituting virtually all known births in New York City for 1961–1963, were plotted on the synodic lunar cycle of 29.53 days. The half cycle with the highest birth rate began the day after first quarter (FQ+1) and thus almost coincided with the brightest half of the lunar month (centered at full moon). This birth rate was 1.01 per cent greater than that for the half cycle beginning the day after last quarter. These findings are compared with those reported in this Journal in 1959. Literature dealing with lunar periodicity in the sexual or reproductive cycle of other mammals is briefly cited.