Contraception, Periodic Abstinence

Key Features

• Periodic abstinence during fertile periods

  • Most effective when intercourse restricted to postovular phase of cycle or barrier method used at other times

  • Women should identify fertile periods (see Infertility, Female)

• "Symptothermal" natural family planning

  • Patient-observed increase in clear elastic cervical mucus, brief abdominal midcycle discomfort ("mittelschmerz")

  • Unprotected intercourse is avoided from shortly after the menstrual period until 48 h after ovulation, as identified by a sustained rise in temperature and the disappearance of clear elastic mucus

• Basal body temperature method shows the safe time for intercourse after ovulation has passed

  • Take temperature immediately upon awakening, before any activity

  • A slight drop in temperature often occurs 12–24 h before ovulation, and a rise of about 0.4°C occurs 1–2 days after ovulation

  • The risk of pregnancy increases starting 5 days before the day of ovulation, peaks on the day of ovulation, and then rapidly decreases to zero by the day after ovulation

• The Standard Days Method

  • Uses a set of beads to remind the couple to avoid intercourse during days 8 through 19 of the cycle

  • Typical use failure rate may be about 12%