Title: The clinical effectiveness of the rhythm method of contraception.

POPLINE Document Number: 510001

Author(s):

Tietze C
Poliakoff SR
Rock J

Source citation:

Fertility and Sterility, 1951;2(5):444-450.

Abstract:

Of 551 women referred to the rhythm clinic at the Free Hospital for Women in Brookline, Massachusetts, 409 used the method for 1 month or longer. They were observed for 7267 months or 605.6 woman-years. 224 participated for less than 1 year, but these patients contributed only 1134 months or 15.6% of the aggregate exposure to the risk of pregnancy. The number of accidental pregnancies recorded during this period was 57. In addition, 209 women discontinued participation without further contact with the clinic. To determine if additional accidental pregnancies were concealed in this group, a trained social worker contacted a selected sample of 69 women and found 10 (14.5%) who were accidentally pregnant when they withdrew from the clinic. If this ratio is applied to the 209 nonreturning patients, the estimated concealed pregnancies is 30, for a total number of accidental pregnancies of 87. This gives a rate of 14.4 pregnancies per 100 woman-years of exposure or 1 unwanted conception for 8 years' reliance on the method. This is much higher than the rates for diaphragm-and-jelly or condom (6 or 7 per 100 years of exposure). For those for whom pregnancy would be dangerous, this method is considered inadequate.

Keywords:

Rhythm Method, Calendar
Evaluation
Use-Effectiveness
Family Planning, Behavioral Methods
Family Planning
Contraceptive Effectiveness
Contraception