Table 4.
Mean Day of Peak Fertility and Mean Day From the End of the Cycle for Peak Fertility Among Women Who Reached Peak, by Observed Cycle Length and Age, in the BioCycle Study, Buffalo, New York, 2005–2007
| Cycle 1 | Cycle 2 | |||
| No. | Mean (SD) | No. | Mean (SD) | |
| Cycle day for all | 189 | 15 (3.3) | 180 | 15 (3.3) |
| Cycle day by cycle length, days | ||||
| <26 | 27 | 13 (2.3) | 29 | 13 (3.0) |
| 26–31 | 138 | 15 (2.8) | 103 | 15 (2.5) |
| >31 | 24 | 19 (3.9) | 33 | 18 (3.7) |
| Unknowna | 0 | 15 | 15 (3.2) | |
| Cycle day by age, years | ||||
| 18–24 | 92 | 16 (3.7) | 82 | 16 (3.5) |
| 25–34 | 44 | 15 (2.5) | 50 | 15 (3.3) |
| 35–44 | 53 | 14 (2.7) | 48 | 14 (2.4) |
| Days from cycle end for all | 189 | 13 (2.9) | 165a | 13 (2.9) |
| Days from cycle end by cycle length, days | ||||
| <26 | 27 | 12 (2.4) | 29 | 11 (2.6) |
| 26–31 | 138 | 13 (2.5) | 103 | 14 (2.3) |
| >31 | 24 | 16 (4.0) | 33 | 16 (3.2) |
| Unknowna | 0 | 15 | ||
| Days from cycle end by age, years | ||||
| 18–24 | 92 | 13 (3.6) | 73 | 14 (3.5) |
| 25–34 | 44 | 14 (2.1) | 47 | 13 (2.3) |
| 35–44 | 53 | 13 (1.9) | 45 | 13 (2.4) |
| Unknowna | 0 | 15 | ||
| Days between high and peakb | 162 | 5 (3.2) | 149 | 5 (2.9) |
Abbreviation: SD, standard deviation.
a
Cycle length is unknown for women who did not call in and report the end of their second cycle.
b
Includes only women who reached high on the monitor before they reached peak.