Birth rate and its correlation with the lunar cycle and specific atmospheric conditions

Department of Obstetrics and Gynecology, The University of Arizona, Tucson, Arizona, United States
American Journal of Obstetrics and Gynecology (Impact Factor: 4.7). 07/2005; 192(6):1970-3. DOI: 10.1016/j.ajog.2005.02.066
Source: PubMed


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.

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    • "Although the mean pressure fell by 0.9 hPa, it rose again by 0.5 hPa during the last day before parturition (Dvorak, 1978). No association between barometric pressure and onset of parturition was detected in two studies involving human births occurring in two different hospitals (Noller et al., 1996a;Morton-Pradhan et al., 2005), but in another, 19 % more births occurred on days when the barometric pressure was below the average of the preceding 8 years compared with days with average or increased barometric pressure (Akutagawa et al., 2007). In the same study, significantly greater barometric pressure fluctuations occurred on days with 2 or more births than on days with one or no births. "
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    ABSTRACT: The present paper summarizes a comprehensive retrospective study that was undertaken to investigate effects of meteorological factors and lunar cycle on gestation length and daily birth rate in cows. To this end, all cattle births in Switzerland between 2008 and 2010 (n = 2,091,159) were related to detailed matched weather recordings. The study revealed some statistically significant effects of climate (temperature, barometric pressure, relative humidity) and weather (thunderstorms, heat index) on gestational length. Thunderstorms on the day before birth reduced the gestation length by 0.5 days. An increase in the birth rate was correlated with the temperature on the day before birth and the barometric pressure 3 days before birth. Differences in the barometric pressure > 15 hPa increased the birth rate by 4%. Nevertheless, the effects were not consistent and the modeled size of effect was so small that a clinical implication is unlikely. Although the daily birth rate was unevenly distributed across the lunar cycle, no clear pattern could be identified. Compared to the mean birth rate across the lunar cycle the highest daily birth rate was detected on day 4 after new moon (+ 1.9%) and the lowest on day 20 (- 2.1%).
    Full-text · Article · Jan 2016 · Preventive Veterinary Medicine
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    • ", as mentioned in the ' Introduction ' , some researchers have been unable to show any significant difference between moon phases and some physiological and behavioral phenomena in humans ( Peters et al . 2001 ; Waldhoer et al . 2002 ; Alves et al . 2003 ; Holzheimer et al . 2003 ; Wolbank et al . 2003 ; Zargar et al . 2004 ; Arliss et al . 2005 ; Morton et al . 2005 ; Robert et al . 2006 ) . Our experience and ideas arising from different research in the fields demonstrate that this matter may have some methodological causes that respecting them would help the researchers in these fields :"
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    ABSTRACT: The present research aims to study the effects of moon phases on serum sodium and lithium levels in rabbits. Twenty-four male rabbits in two separated groups (sodium and lithium groups) were studied. In each study group, there were 12 rabbits, and 40 mg/kg lithium carbonate was orally administered to rabbits in one group on a daily basis. On days 1, 5, 9, 13, 15, 17, 21, and 25 of a lunar month, blood samples were taken from all rabbits. The highest mean of serum sodium levels was observed on the first day and the lowest mean was related to the 15th lunar day. Significant difference was noted between the 1st, 5th, 13th, and 17th days of the lunar month. In the lithium group, there was also a decreasing trend from the 1st to 17th lunar day in serum lithium level, but there was no statistical difference between lithium serum levels on different days of the lunar month. Fluctuations of bodily fluids under the influence of moon phases can be an effective factor in the changes in serum sodium levels. It is probable that due to small sample size we could not find significant difference in serum lithium levels.
    Full-text · Article · Aug 2011 · Biological Rhythm Research
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