Managing infertility with fertility-awareness methods

The Billings method 

The so-called ‘ovulation method of natural family planning’ was first described by Billings and collaborators in 1972. 4 The method teaches how to score daily changes in the sensation and appearance of vaginal mucus, ranging from 1 (no discharge and dry) to 4 (transparent, stretchy, and slippery). At the time, it was heavily promoted for contraception because of ideological objections to other forms of family planning. Not surprisingly, the Billings method has been severely criticized, not only because of the inflated claims made by its proponents but also because the efficacy was never proven. The controversy surrounding family planning methods in the 1970s was perhaps most heated amongst Catholics and heralded the start of an ideological divide between progressive and conservative reproductive centers at Catholic universities around the world. 5 Recent studies, however, have provided compelling arguments for a reappraisal of the techniques used in natural family planning methods, not for contraception but rather to expedite pregnancy in couples who wish to conceive.

Monitoring vaginal mucus 

Data from the World Health Organization show that women with regular cycles (26 to 32 days) do not get pregnant if intercourse takes place before Day 8 or after Day 19. 6 In the remaining 12 days, the probability of conception varies greatly. In fact, the fertility window—defined as the probability of 5% or greater that intercourse will result in pregnancy—is really only six days. By monitoring changes in the sensation and appearance of the vaginal secretions, it is possible to identify this window and the peak fertile day2, 3, 7, 8 ( Table 1 ). The type of cervical mucus correlates with the day-to-day probability of conception, which, in couples without reproductive problems, reaches 39% on the peak fertile day. 8 In other words, regardless of the timing of intercourse relative to ovulation, the probability of pregnancy is highest on the day of the most fertile-type mucus. 9 Hence, changes in vaginal secretions can predict not only the fertile days of the cycle, but also the likelihood of conception. Other methods, such as cycle monitoring by vaginal ultrasound and/or urinary luteinizing hormone (LH) detection, do not provide information as to the likelihood of conception on a particular day. 9 These techniques are also relatively expensive, inconvenient, and do not determine the beginning of the fertile window.

TABLE 1. Scoring of cervical mucus by observation * †

	Characteristic	Score
	Sensation
	No sensation, dry…………	0
	Slightly moist…………	1
	Wet slippery sensation ……………………	2
	Subtotal ………………	□
	Appearance
	No discharge nor any noticeable mucus …………………	0
	Thick, whitish, yellowish, sticky mucus ……………	1
	Clear, stretchy, fluid, watery mucus ………………….	2
	Subtotal …………………	□
	A total score of 3 or 4 indicates peak fertility day

* Adapted from reference 12. † The cervical mucus is checked by introducing two fingers in the vulva or vagina sometime during the day or in the evening (before sexual intercourse).

The fertile window lasts the same amount of time in women aged 19–39 years; but the daily probability of pregnancy declines with age. Chances are twice as high for women aged 19–26 years than for those aged 35–39 years. 10 After taking the woman's age into account, it is important to note that the likelihood of conception during the fertile window is also significantly lower if the partner is 35 years or older.

Two prospective cohort studies have recently confirmed the value of FAM for expeditious conception. A German study found that 81% and 92% of women who used natural family planning methods to conceive from the first cycle onwards became pregnant within 6 and 12 cycles, respectively. 11 The study included a cohort of couples using natural family planning methods from their first cycle onwards. Only women trying for a first pregnancy under the conditions of the study (which may not be necessarily the first pregnancy for the couple) were included in the analysis. An Italian study 12 reported a probability of pregnancy of 0.003 on days with no noticeable vaginal secretions against 0.29 on the day with the most fertile-type mucus ( Table 2 ). The pattern of changes in vaginal secretions is also often consistent from one menstrual cycle to another, although occasionally a noncharacteristic pattern can be observed. Such cycles may be abnormal and indicative of reduced fertility, but this requires further evaluation.

TABLE 2. Estimates of the probability of conception according to vaginal secretion observations on the day of intercourse *

	Vaginal secretion	Probability of conception	Mean S.D. †	95% confidence interval
	Dry	0.0033	0.0021	0.0006–0.0088
	Slightly moist	0.0125	0.0058	0.0038–0.0262
	Damp, sticky	0.0248	0.0084	0.0120–0.0448
	Slippery, clear	0.2858	0.0418	0.2083–0.371

* Adapted from reference 12. † S.D.= standard deviation

Charting basal body temperature 

Between the ages of 20 and 40, most women will have regular ovulatory menstrual cycles. However, even with regular menses some women do not ovulate or have an inadequate luteal phase. Historically, the first ovulation test was based on daily measurements of basal body temperature (BBT). Today, ovulation is usually ascertained by measuring blood progesterone levels or by an endometrial biopsy during the presumed luteal phase. Histological dating has been used to reflect the cumulative effect of the post-ovulatory rise in progesterone levels on the endometrium, thus providing more information on the quality of the luteal phase. However, to interpret the effect of progesterone on the endometrium, the day of ovulation also needs to be determined and is usually done by serial LH measurements on daily urine or blood samples.

Recently, a large multicenter study confirmed that histological dating of endometrial biopsy measured by urinary LH has no value in assessing the quality of the luteal phase in patients with infertility. 13 These investigators found that the urinary LH peak was a false sign of ovulation in more than 7% of women with or without infertility. Furthermore, in patients with unexplained infertility there may be a delay in the onset of the luteal phase after the LH peak which cannot be detected unless daily blood samples are taken for assay of LH and progesterone levels. 14

Because of the limitations of endometrial dating, the preferred method for detecting ovulation and determining the quality of the luteal phase it to measure plasma progesterone. Unless this is done on daily samples, there is no information on the onset of the progesterone rise nor consequently on the duration of the luteal phase. In the absence then of a simple clinical tool, daily measuring of the BBT can provide valuable information. While this method is not useful for determining the ideal timing of sexual intercourse, it is an acceptable and relatively accurate method for evaluating ovulation. 15 Self-assessment of fertility by charting BBT and observing vaginal secretions over a period of 100 days can be highly recommended to women when they start worrying about delays in conception ( Figure 1 ).

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Figure 1. Daily recordings of cervical mucus and a basal body temperature chart demonstrate: •A fertility window of six days with peak fertility on Days 3 and 4; •An interval of 10 days between the end of the fertility window and the onset of menstruation; •An hyperthermic plateau between the end of the fertility window and the onset of menstruation confirming the presence of a normal ovulatory cycle.

Benefits of FAM 

Fertility-awareness methods offer benefits to women attempting pregnancy for several reasons. First, the self-assessment of cervical mucus allows them to identify the days with the highest probability of conception. At the same time, charting BBT provides information about ovulation and the duration of the luteal phase and helps to interpret the mucus findings. When measured over a period of three cycles, the combined methods provide basic information on the quality of cervical mucus and ovulatory function.

Second, timing sexual intercourse to the peak fertile days by assessing the cervical mucus is unlikely to cause as much stress to couples as making sure to have sexual intercourse every two or three days to coincide with ovulation. In fact, the frequency of sexual intercourse increases naturally in humans and other mammals during the follicular phase, peaks at the time of ovulation, and declines abruptly thereafter. 16 Circulating testosterone levels—which are linked to sexual desire—rise during the follicular phase, and the mid-cycle testosterone peak happens in conjunction with the LH surge.

Third, two recent studies found that sexual intercourse on peak mucus days improved spontaneous pregnancy rates in couples with fertility problems. In women with unexplained infertility, the fertile window lasts no more than three days. 9 Observing vaginal secretions allows timing intercourse to happen during this short but most fertile period of the menstrual cycle. In another prospective study involving seven European family planning centres, 782 couples recorded daily the nature of cervical mucus and also when they had intercourse. 10 It found that on days where women had poor vaginal secretions, intercourse with an older partner (late 30s and early 40s) is 50% less likely to lead to a pregnancy when compared with a younger partner. When secretions were more conducive for sperm transport, the negative effect of male age diminished steadily from 21% on days with damp secretions to 11% on days with thick mucus, and finally to only 4% on days with the most fertile-type mucus. Therefore, the effect of sub-optimal sperm quality on fecundity can also be reduced by timing intercourse on days with optimal mucus secretion.

Fourth, the use of FAM for expeditious conception facilitates pregnancy occurring under optimal environmental conditions. Many factors, such as the consumption of alcohol and caffeine, medication, smoking, or contact with potentially toxic products, create detrimental environmental conditions for conception. An awareness of proper timing for fertility may also bring about awareness of these environmental factors.

Finally, even if pregnancy is not achieved, FAM yield important information on cervical, ovulatory, and sexual functions. Rather than advocating one year of expectant management as standard before starting fertility exploration, the findings on reproductive functions obtained through FAM can be used at an early stage to help tailor the fertility investigation. The information can help to avoid both over- and under-treatment.17, 18, 19

Current fertility monitors such as ClearPlan® Easy fertility monitor, OvaCue® fertility monitor, and Ovulon™ are based on measuring hormone metabolites or electrical resistance to define the fertility window and ovulation as signaled by the LH peak. A comparative study between ClearPlan Easy fertility monitor and self-assessment of cervical mucus found that monitoring the urine for estrogen and LH metabolites and observing cervical mucus are similar for determining the peak fertility; but the fertility monitor tends to underestimate while the self-assessment of cervical mucus tends to overestimate the actual fertile phase. 20 The beginning of the fertile phase as determined by the ClearPlan Easy fertility monitor is, on average, almost two days later than the beginning of the fertile phase as determined by the self-observation of cervical mucus. However, it is important to note that these methods have not been compared with pregnancy as an out-come measurement. Fertility monitors and FAM do not require ongoing medical supervision, but the self-assessment of cervical mucus and BBT charting will require some initial assistance and guidance. Our center is currently evaluating the usefulness of a device (www.symfo.com) that allows telemonitoring of the fertility awareness recordings and assists the user in interpreting the data.

Conclusions 

This combination of active and expectant management of infertility based on observing cervical mucus and charting BBT can be recommended to couples attempting pregnancy, particularly if they worry about a delay in conception. FAM not only maximize the chances for spontaneous and expeditious conception, but also provide information on reproductive functions, which can be used to tailor further management to the individual couple, thereby preventing both under- and over-treatment. Further research is needed to compare this active expectant management with other medical approaches, such as intrauterine insemination and other treatments.