Breastfeeding and the Symptothermal Method

Abstract

This prospective study was conducted among experienced users of periodic abstinence methods in Sydney, Montreal, and Birmingham (England) in order to describe the relationship between a laboratory measurement of ovulation and the natural symptoms of fertility during breastfeeding. Daily urinary estrogen and pregnanediol glucuronide assays were used to estimate the date of ovulation and to determine potentially fertile days. A standard set of Symptothermal Method (STM) rules was applied to daily STM records to assess the correspondence of the natural symptoms of fertility to the underlying hormonal profile. The STM symptoms and rules accurately identified 77-94 percent of the women's potentially fertile days, but abstinence was also recommended on about half of the days when the women were not fertile. An integrated set of common rules for STM use during breastfeeding is highly sensitive but not specific in its ability to screen for ovulation.

Efficacy of a New Postpartum Transition Protocol for Avoiding Pregnancy

“…4 .7) at 6 months of use (among 57 participants who responded). The one-way repeated measure ANOVA of the 3 time periods showed no significant effect (F (2,21) ϭ 0.40; P ϭ .67).…”

“…3 There is reduced fertility while not in cycles even when ovulation returns, and although two thirds of women ovulate before their first menses, only half of these (one third of breastfeeding women) have adequate pregnanediol excretion and luteal phase lengths to theoretically sustain a pregnancy. 4 Because it is difficult to predict which subset of women will ovulate before their first menses, it is important to give women tools to detect their return to fertility should they choose to use NFP to avoid pregnancy.…”

“…7 Temperature measurements may not be accurate in the first cycles after the return of menses, 8 and integrated rules of an NFP method that used mucus and temperature signs showed low specificity and positive predictive value but good sensitivity in predicting the return of fertility. 4 One study has suggested that breastfeeding women who adhered to the rules of the ovulation method (based on identifying when mucus becomes fertile) after menses returns may have a higher unintended pregnancy rate than those who were not lactating. 9 In addition, there is confusion among users about the interpretation of the natural signs of fertility during the breastfeeding transition, 10 especially if these women have had irregular cycles previously.…”

“…9 In addition, there is confusion among users about the interpretation of the natural signs of fertility during the breastfeeding transition, 10 especially if these women have had irregular cycles previously. 11 In studies that have investigated the efficacy of NFP during the breastfeeding transition, 4,6,[11][12][13][14][15][16][17][18] the pregnancy rates at 12 months have ranged from 11.1 13,15 to 24 per 100 women. 16 A more recent study of a new calendar-based NFP method (the Bridge Method), to be used once a woman has had her first menses, determined a pregnancy rate of 11.2 per 100 women over a typical 6-month period of use, 18 but it assumes that women use the lactational amenorrhea method (LAM) before this.…”

Protocol for determining fertility while breastfeeding and not in cycles

“…Use of current methods of NFP (during breastfeeding) results in overestimating the actual days of fertility, prolonged and confusing mucus patterns, long periods of abstinence, and an increased pregnancy rate (1)(2)(3)(4). Finding more accurate and simple ways of determining fertility while breastfeeding would be a help to couples wishing to use natural methods.…”