Objective: To study the relationship between lunar position and the day of delivery; to investigate the synodic distribution of spontaneous deliveries, especially in relation to the presence of a full moon.
Study design: Retrospective analysis of 1248 spontaneous full-term deliveries in three-year period (36 lunar months), setted at Department of Obstetrics and Gynaecology, Civil Hospital, Fano (Marche, Italy), using circular statistics techniques.
Results: A connection between the distribution of spontaneous full-term deliveries and the lunar month was found. The effect of the phases of the moon seems to be particularly relevant in multiparae and plurigravidae; in these cases, the mean day of delivery corresponds to the first or second day after the full moon.
Conclusions: In this paper the effect of lunar phases on the time of delivery is shown. This influence seems to be especially relevant in the case of multiparae and plurigravidae. Nevertheless, it is too weak to allow for prediction regarding the days with the highest frequency of deliveries.