Breastfeeding and the symptothermal method.

ABSTRACT

PIP: Periodic abstinence from sexual intercourse as a pregnancy prevention technique is sometimes the sole method used by women. The effectiveness of this technique is based on the woman's ability to fully understand her own menstrual cycle. Factors like breastfeeding and endocrine irregularities have been shown to interfere with a women's ability to determine periods of fertility. This article reports on a prospective study on the relationship between breastfeeding and hormonal levels, as a measurement of fertility, in women using periodic abstinence. The 73 women in this study were from England, Canada, and Australia. All women were breastfeeding. Daily symptothermal method (STM) records, which documented the cervical mucus conditions and basal body temperature, were kept. All women had experienced healthy pregnancies. Chi-square analysis and the analysis of variance (ANOVA) were the statistical methods employed. Significantly less abstinence is recommended by the STM rules during the anteovulation stage than during either of the later stages. Significantly less abstinence is also recommended during amenorrhea than after the first menstrual period. During the anteovulation stage, significantly fewer days were reported with fertile-type mucus than later stages. First ovulations were reported in 48 women (65%) during amenorrhea; of these, 25 (52%) were characterized as having adequate luteinization for conception. The STM method used in this study was considered to be sensitive but lacked specificity.