Natural Signs of Fertility
One of the early and reliable signs of fertility in a woman’s menstrual cycle is a change in sensation and mucus (or discharge) at the vulva which develops over several days. Any mucus seen is likely to become thinner and clearer and the sensation becomes wet and then slippery. Hormone and ultrasound studies show that the most fertile time in the cycle coincides with what is referred to as the Peak day on the chart. This is the last day of the slippery sensation at the vulva which may be accompanied by clear mucus which may form strings.
The Peak day relates very closely to the time of ovulation (ie when the egg is released). In most cycles ovulation occurs on the Peak day, but in some cycles ovulation may not occur until day 1 or day 2 before or after the Peak. The egg lives for a maximum of 24 hours after being released1.
A daily record of the sensation and appearance of the mucus (charting) reveals the times of infertility, potential fertility and the Peak of fertility. Teaching a woman this information gives her fertility-awareness.
Fertility Awareness-Based Methods (FABMs)
FABM is the term given to the a method that uses these naturally occurring signs of fertility in a woman’s cycle. Using these methods, a woman can be taught to observe her individual and reliable physiological signs that show whether she is fertile or infertile on a day-to-day basis.
Couples can use the methods to achieve a pregnancy by identifying the time of ovulation based on mucus signs. This has good evidence for assisting couple to conceive2.
FABM charting can also be useful to specially trained doctors who can identify and treat abnormalities demonstrated in the charts, which can then lead to successful treatment of the underlying causes of infertility. Read more below under Benefits of Fertility-Awareness.
To avoid pregnancy a couple abstains from intercourse during a woman’s fertile phase. Evidence-based studies have shown that the three FABMs are 97-99% effective in avoiding pregnancy when followed correctly, and are comparable to use of the Oral Contraceptive Pill (OCP) in real-world conditions3,4,5 .
Fertility-awareness is unique because unlike other methods of family planning, no drugs, devices or surgical procedures need be used. It is the only true method of family planning since it allows the couple to decide from day-to-day or cycle-to-cycle if they wish to use their knowledge of their fertility to avoid or achieve a pregnancy.
For more information on each of the fertility awareness-based methods (FABMs) available in Australia and New Zealand, click here.
Benefits of Fertility-Awareness
No drugs needed
No ongoing cost
A couple can switch from avoiding to achieving a pregnancy at any point in time
Encourages and supports couples to take a shared responsibility in their sexual and procreative health
Helps couples to strengthen their communication skills, engender mutual respect through a deeper understanding of each other and develop greater friendship and intimacy because they are working together on a common goal.
Charting can reveal issues including: polycystic ovary syndrome (PCOS), endometriosis, ovarian cysts, irregular bleeding, and chronic cervical discharge, infection, inflammation of the cervix
Women with the charting abnormalities above or other issues such as miscarriages, ectopic pregnancies, premenstrual syndrome and postnatal depression can be referred to doctors (GPs or Specialist Obstetricians & Gynaecologists) who are trained in evaluating and treating abnormalities of FABM charts in a way that is cooperative with the cycle to restore function, as opposed to suppressing or destroying it.
Q: Isn’t Natural Family Planning just the Rhythm Method?
A: No. The Rhythm method is unreliable and is not utilised as a modern fertility awareness-based method (FABM) of family planning. Current evidence-based Natural Family Planning in Australasia involves: the Billings Ovulation Method®, the Creighton Model System, and the Sympto-thermal method.
Q: Do FABMs really only have a contraceptive effectiveness rate of 76%?
A: No, this is incorrect and misleading. This low estimated figure was obtained from retrospective surveys in 1995 and 2002 that pooled data for all FABMs including the rhythm method, without differentiating the higher effectiveness of other individual FABMs. It has repeatedly been misrepresented erroneously by academic publications6 and by organisations that do not have expertise in fertility-awareness. More correct contraceptive effectiveness rates for FABMs are significantly higher7 and are comparable with other hormonal methods of contraception:
Method Typical use efficacy effectiveness Sympto-thermal 99.4% 98.2% 8 Creighton 99.5% 96.8% 9 Billings 99.5% 89.5% 4,10
Q: Can FABMs be used by women who have irregular cycles?
A: Yes, FABMs are appropriate for and can be used successfully by women who have irregular cycles.
Q: Should I have a “day 21” progesterone level done?
A: Performing a “day 21” progesterone level (in infertility workup) is supposed to be a measure of mid-luteal phase progesterone. In practice, though, “day 21” does not necessarily correspond to a mid-luteal measurement since this timing itself relies on the Rhythm method and a regular 28-day menstrual cycle. One recent study found only 15% of woman had a 28-day menstrual cycle.11 A true mid-luteal point for measuring progesterone can be determined by women or doctors/teachers familiar with FABMs. A “day 21” progesterone level alone also does not give adequate information about the various luteal phase deficiency subtypes.
Q: Should I rely on my smartphone menstrual cycle app to predict my fertile times?
A: The majority of smartphone apps rely on either either calendar-based or symptom-based methods. Recent studies have demonstrated the lack of reliability of these apps for predicting ovulation11,12. On the other hand, fertility awareness methods based on cervical mucus have high reliability in identifying ovulation and fertile/infertile times in in the menstrual cycle13.
- Relationship of the Estimated Time of Ovulation Measured by Various Hormonal Methods and the Woman’s Observation of the Peak Day, Published Evaluations. Hilgers TW. Reproductive Anatomy and Physiology – A Primer for Fertility Care Professionals. Second Edition table 7-3 pg66
- World Health Organization, Task Force on Methods for the Determination of the Fertile Period (1983) A prospective multicentre trial of the ovulation method of natural family planning. III. Characteristics of the menstrual cycle and of the fertile phase. Fertil Steril. 40:773-778.
- Turner (2016) Fertility-awareness practice and education in general practice. Aust J Prim Health. 22:375-376.
- Pallone, Bergus (2009) Fertility awareness-based methods: another option for family planning. J Am Board Fam Med. 22(2):147-57.
- Trussell (2011) Contraceptive failure in the United States. Contraception. 83(5):397-404.
- Family Planning Alliance Australia (2014) Efficacy of Contraception Methods. [cited 14 Jan 2018.] Available from URL: http://familyplanningallianceaustralia.org.au/wp-content/uploads/2014/11/FPAA_Efficacy_SCREEN.pdf.
- Turner (2017) In response to: Current barriers and potential strategies to increase the use of long-acting reversible contraception to reduce the rate of unintended pregnancies in Australia: An expert roundtable discussion. Aust N Z J Obstet Gynaecol. 57(6):E15-E16.
- Frank-Herrmann, et al. (2007) The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple’s sexual behaviour during the fertile time: a prospective longitudinal study. Hum Reprod. 22:1310-9.
- Hilgers, Stanford (1998). Creighton Model NaProEducation Technology for avoiding pregnancy. Use effectiveness. J Reprod Med. 43:495-502.
- Bhargava, et al. (1996) Field trial of billings ovulation method of natural family planning. Contraception. 53:69-74.
- Johnson, Marriott, Zinaman (2018) Can apps and calendar methods predict ovulation with accuracy? Curr Med Res Opin. 34(9):1587-1594.
- Freis, et al. (2018) Plausibility of Menstrual Cycle Apps Claiming to Support Conception. Front Public Health. 6:98.
- Brown (2011) Types of ovarian activity in women and their significance: the continuum (a reinterpretation of early findings). Human Reproduction Update. 17:141-158.