Table 1 Summary menses of recorded subjects.

Age atNumber of recordedPeriod length in days
(mean ± SD/median)*
Percent of time
synchronized to the
synodic month (f: full
moon; n: new moon)
Percent of time
synchronized to the
anomalistic or
tropical month (a:
apogee; p: perigee; ma,
mi: maximum,
minimum lunar
standstills)
Nocturnal
light
exposure
Record
begin
Record
end
YearsMensesBirths‡≤35 years>35 years≤35 years>35 years≤35 years>35 years
Subject 1§215332337332.2 ± 4.2/32.028.4 ± 2.1/28.031.8 (f + n)45.0 (f + n)0.014.6
(a, ma,
and mi)
Low
Subject 2§195031ǁ331429.2 ± 2.1/29.026.8 ± 3.0/26.056.3 (f + n)14.3 (n)7.5 (mi)18.3
(a + mi)
Low
Subject 3245127360030.4 ± 3.7/30.025.5 ± 2.3/25.041.7 (f)13.8 (f + n)3.4 (p)21.4
(a + p)
Low
Subject 4234219259029.1 ± 3.7/29.025.8 ± 2.1/26.065.0 (f)0.028.1
(a, p, and
ma)
33.3
(a, p, and
mi)
Low
Subject 5255328368227.8 ± 1.8/28.026.7 ± 3.0/27.02.0 (n)25.7 (f + n)62.5
(a, p, ma,
and mi)
39.0
(a, p, ma,
and mi)
Medium
Subject 6194425ǁ226226.0 ± 4.9/25.024.7 ± 2.4/25.00.00.07.1 (p)0.0High
Subject 7§255025297230.2 ± 2.9/30.026.4 ± 2.0/26.027.1 (f + n)19.4 (f + n)0.013.8
(p and ma)
Low
Subject 8315120195331.5 ± 6.4/29.025.8 ± 3.0/26.00.00.011.8
(a and p)
12.1 (p)High
Subject 9254217229028.6 ± 2.2/29.027.2 ± 1.4/27.036.0 (f + n)37.5 (f)25.8
(a and
ma)
16.0
(a and p)
Low
Subject 10334714182027.8 ± 4.8/27.026.9 ± 4.7/26.00.00.00.018.2 (p)Medium
Subject 1129389104126.5 ± 1.6/26.00.017.6
(a and p)
High
Subject 12§12#18685028.5 ± 4.9/28.020.0 (f + n)28.5 (p)Low
Subject 1318257108030.3 ± 6.2/31.032.3 (f + n)0.0Low
Subject 143137666030.6 ± 4.9/30.014.3 (n)3.8 (ma)Low
Subject 15§12#17549032.4 ± 5.6/30.527.3 (f)0.0Low
Subject 1645549114027.1 ± 4.5/26.05.0 (n)16.7 (p)Low
Subject 17384911166026.1 ± 3.7/26.00.029.7
(a and ma)
Medium
Subject 18364913180026.5 ± 2.8/26.00.036.3
(a, p,
and mi)
High
Subject 194551681025.7 ± 2.5/26.00.00.0Low
Subject 204348570025.4 ± 6.6/24.00.011.3 (mi)Medium
Subject 21§40465109026.3 ± 5.7/25.00.00.0Medium
Subject 22365014196026.0 ± 5.0/26.00.019.7 (a, ma,
and mi)
Medium
Summary41121729.4 ± 1.9/28.926.3 ± 0.9/25.923.6%9.5%13.1%17.7%

*Period was determined by measuring the distances between the menses.

†Synchronization was determined on the actograms; only intervals at which menses occurred at least three times in a row at full (f) or new (n) moon were judged as synchronized.

‡Includes miscarriages; with the exception of subject 21, only the births occurring during the recorded years are included. For subject 21, the births of the two daughters (subjects 12 and 15) are included, although they happened long before she started the recording of her menses.

§Relations between subjects. Subject 8 is the mother of subjects 1 and 2; subject 21 is the mother of subjects 11 and 14. Actograms of subjects 19 to 21 are not shown in the figures.

ǁRecording was interrupted for several years.

¶Menses oscillated for five to six cycles with a period of 29.5 days and occurred during the waxing moon. These women were judged as not synchronized because the phase of menses onset was not at full or new moon.

#Recording started at menarche.