Abstract
Objective
To provide estimates of the probabilities of conception according to vulvar mucus
observations classified by the woman on the day of intercourse.
Study design
Prospective cohort study of 193 outwardly healthy Italian women using the Billings
Ovulation Method. Outcome measures include 161 conception cycles and 2594 non-conception
cycles with daily records of the type of mucus and the occurrences of sexual intercourse.
Results
The probability of conception ranged from 0.003 for days with no noticeable secretions
to 0.29 for days with most fertile-type mucus detected by the woman. The probability
of most fertile type mucus by day of the menstrual cycle increased from values <20%
outside of days 10–17 to a peak of 59% on day 13.
Conclusion
Regardless of the timing of intercourse in the menstrual cycle, the probability of
conception is essentially 0 on days with no secretions. This probability increases
dramatically to near 30% on days with most fertile-type mucus, an association that
accurately predicts both the timing of the fertile interval and the day-specific conception
probabilities across the menstrual cycle.
Keywords
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Article info
Publication history
Accepted:
July 24,
2005
Received in revised form:
June 9,
2005
Received:
July 27,
2004
Identification
Copyright
© 2005 Elsevier Ireland Ltd. Published by Elsevier Inc. All rights reserved.
