CoChat
Sign Up
Cited by 10Maternal and Perinatal Health InterventionsCircadian rhythm and melatoninHistorical Studies on Reproduction, Gender, Health, and Societal Changes

Novel perspectives on the influence of the lunar cycle on the timing of full-term human births

Matsumoto, Shin-ichiro, Shirahashi, Kiyohiko·2020·Chronobiology International
DOI 10.1080/07420528.2020.1785485
Open this paper in CoChat — free account

Abstract

It is claimed by some that the number of births occurring at the time of the full moon is greater than other phases of the lunar cycle; however, many publications fail to substantiate the claim leading to the conclusion it is myth. We tested using a novel approach the null hypotheses: (i) human birth is not lunar cycle-dependent and (ii) the number of births occurring at or around the time of the full moon is not different from the number occurring at the time of the other phases of the lunar cycle. We reviewed the birth records from 1 January 1996 to 16 March 2007 of the obstetric department of our hospital, which was then located in a relatively undeveloped area of Fukutsu city in Fukuoka Prefecture of southern Japan. A total of 1507 births satisfied all inclusion criteria, among others, being full-term and following spontaneously initiated labor. When the birth data were analyzed as done by other investigators, i.e. total number of births per lunar day, lunar phase was not found to be influential. However, more detailed analyses on the subset of babies born specifically during the nighttime hours (N = 362) revealed the number of births varied in relation specifically to the changing amount of moonlight during the nighttime at different stages of the lunar cycle, with highest number of births at or around the time of the full moon. In contrast, analyses on the subset of babies born specifically during the daytime hours (N = 377) revealed the number of births varied in relation specifically to the changing amount moonlight during the daytime at different stages of the lunar cycle, with the highest number of births at or around the time of the new moon. The initiation and culmination of human birth are typically a nocturnal process. The findings of this investigation are consistent with the hypothesis natural nighttime parturition is influenced by lunar phase, particularly the full moon, and, thus, they are consistent with the belief the moon exerts an affect upon the timing of human birth. We speculate the long-hold belief of the association between birth and lunar phase may be based on historical observations that in the absence of artificial light at night nocturnal births occurred in elevated number when the full moon brightly illuminated the nighttime sky.

Integrity signals

Registry

Crossref · 10.1080/07420528.2020.1785485

Cites

36 of 36 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • In all cases except subject 6, there were intervals during which menses onsets recurred at times of the full or new moon, i.e., menstrual cycles oscillated in synchrony with the synodic lunar month.

    “Notably, in all cases with the exception of subject 6, there were intervals during which menses onsets recurred at times of the full or the new moon, meaning that the ovulations that preceded the menses onsets would have happened around the times of the new or the full moon, respectively (17, 18).”

    From Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon (2021) · cites this paper as [18]

  • The elevation of births at the full moon occurs during the night, whereas births at the new moon tend to occur during the daytime.

    “More recent findings indicate that the elevation of births at the full moon occurs during the night, whereas births at the new moon tend to occur during the daytime (18).”

    From Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon (2021) · cites this paper as [18]

  • The duration of the interval between ovulation and menses onset shows little variability among individuals and over age.

    “Duration of the interval between ovulation and menses onset shows little variability among individuals and over age (18–20).”

    From Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon (2021) · cites this paper as [18]

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
Matsumoto, S.-I., & Shirahashi, K.
Affiliations
  • Department of Obstetrics and Gynecology, Munakata Suikokai General Hospital, Fukutsu, Fukuoka Prefecture, Japan
  • Munakata Suikokai General Hospital (JP)
ORCID
Venue
Chronobiology International
Publisher
Informa UK Limited
Published
2020-07-02
Volume
37
Issue
7
Pages
1082-1089
ISSN
  • 0742-0528 (ISSN-L)
  • 1525-6073
DOI
10.1080/07420528.2020.1785485
OpenAlex
W3044196709
Cited by
10
References
36
Citations by year
2025: 3 · 2024: 2 · 2023: 1 · 2022: 1 · 2021: 2 · 2020: 1
FWCI
0.76
Type
journal article
Language
en
Open access
closed
Locations
  • Chronobiology International (publishedVersion)
  • PubMed (publishedVersion)
Funders
no specific funding for this work
Topics
  • Health Sciences › Medicine › Obstetrics and Gynecology › Maternal and Perinatal Health Interventions
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
  • Social Sciences › Arts and Humanities › History › Historical Studies on Reproduction, Gender, Health, and Societal Changes
Keywords
lunar cycle, full moon, birth timing, lunar phases, moonlight, term birth, new moon
MeSH terms
Circadian Rhythm, Female, Humans, Japan, Pregnancy, Moon, Parturition

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review