Overview
Fertility awareness–based (FAB) methods involve identifying the fertile days of the menstrual cycle, whether by observing fertility signs, such as cervical secretions and basal body temperature or by monitoring cycle days, and might include use of Food and Drug Administration–cleared contraceptive software applications (Box F1) (Table F1). FAB methods can be used in combination with abstinence or barrier methods during the fertile time. If barrier methods are used, see Classifications for Barrier Methods (Appendix E).
No medical conditions worsen because of FAB methods. In general, FAB methods can be used without concern for health effects in persons who choose them. However, multiple conditions make their use more complex. The existence of these conditions suggests that use of these methods should be delayed until the condition is corrected or resolved, or persons using FAB methods need special counseling; and a provider with particular training in use of these methods is generally necessary to ensure correct use.
FAB methods do not protect against sexually transmitted infections (STIs), including HIV infection, and patients using FAB methods should be counseled that consistent and correct use of external (male) latex condoms reduces the risk for STIs, including HIV infection.[1] Use of internal (female) condoms can provide protection from transmission of STIs, although data are limited.[1] Patients also should be counseled that pre-exposure prophylaxis, when taken as prescribed, is highly effective for preventing HIV infection.[2]
Box F1. Definitions for terms associated with fertility awareness–based methods
- Symptoms-based methods: FAB methods based on observation of fertility signs (e.g., cervical secretions or basal body temperature) such as the cervical mucus method, the symptothermal method, and the TwoDay method.
- Calendar-based methods: FAB methods based on calendar calculations such as the calendar rhythm method and the standard days method.
- Accept: No medical reason exists to deny the particular FAB method to a patient in this circumstance.
- Caution: The method normally is provided in a routine setting but with extra preparation and precautions. For FAB methods, this usually means that special counseling might be needed to ensure correct use of the method by a patient in this circumstance.
- Delay: Use of this method should be delayed until the condition is evaluated or corrected. Alternative temporary methods of contraception should be offered.
Abbreviation: FAB = fertility awareness–based.
Table F1. Fertility awareness–based methods, including symptoms-based and calendar-based methods
Table F1. Fertility awareness–based methods, including symptoms-based and calendar-based methods
| Condition |
Category |
Clarification/Evidence/Comment |
| Symptoms-based method |
Calendar-based method |
| Personal Characteristics and Reproductive History |
| Pregnancy |
NA |
NA |
Clarification: FAB methods are not relevant during pregnancy. |
| Life stage |
Comment: Menstrual irregularities are common in postmenarche and perimenopause and might complicate the use of FAB methods. |
| a. Postmenarche |
Caution |
Caution |
| b. Perimenopause |
Caution |
Caution |
| Breastfeeding |
Comment: Use of FAB methods when breastfeeding might be less effective than when not breastfeeding. |
| a. <6 weeks postpartum |
Delay |
Delay |
Comment: Persons who are primarily breastfeeding and are amenorrheic are unlikely to have sufficient ovarian function to produce detectable fertility signs and hormonal changes during the first 6 months postpartum. However, the likelihood of resumption of fertility increases with time postpartum and with substitution of breast milk by other foods. |
| b. ≥6 weeks postpartum |
Caution |
Delay |
| c. After menses begin |
Caution |
Caution |
Clarification: Once fertility signs are noted, particularly cervical secretions, then symptoms-based methods can be used. First postpartum menstrual cycles while breastfeeding vary significantly in length. Return to regularity takes several cycles. When there have been at least three postpartum menses and cycles are regular again, a calendar-based method can be used. When there have been at least four postpartum menses and the most recent cycle lasted 26–32 days, the standard days method can be used. Before that time, a barrier method should be offered if the patient plans to use a FAB method later. |
| Postpartum (nonbreastfeeding) |
| a. <4 weeks |
Delay |
Delay |
Clarification: Nonbreastfeeding persons are not likely to have detectable fertility signs or hormonal changes before 4 weeks postpartum. Although the risk for pregnancy is low, ovulation before first menses is common; therefore, a method appropriate for the postpartum period should be offered. |
| b. ≥4 weeks |
Accept |
Delay |
Clarification: Nonbreastfeeding persons are likely to have sufficient ovarian function to produce detectable fertility signs, hormonal changes, or both at this time; likelihood increases rapidly with time postpartum. Calendar-based methods can be used as soon as three postpartum menses have been completed. Methods appropriate for the postpartum period should be offered before that time. |
| Postabortion (spontaneous or induced) |
Caution |
Delay |
Clarification: After abortion, it is possible for ovarian function to produce detectable fertility signs, hormonal changes, or both; likelihood increases with time postabortion. Calendar-based methods can be used following at least one postabortion menses (e.g., persons who before this pregnancy primarily had cycles of 26–32 days can then use the standard days method). Methods appropriate for the postabortion period should be offered before that time. |
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Table F1. Fertility awareness–based methods, including symptoms-based and calendar-based methods
| Condition |
Category |
Clarification/Evidence/Comment |
| Symptoms-based method |
Calendar-based method |
| Reproductive Tract Infections and Disorders |
| Irregular vaginal bleeding |
Delay |
Delay |
Clarification: Presence of this condition makes FAB methods unreliable. Therefore, barrier methods should be recommended until the bleeding pattern is compatible with proper method use. The condition should be evaluated and treated as necessary. |
| Vaginal discharge |
Delay |
Accept |
Clarification: Because vaginal discharge makes recognition of cervical secretions difficult, the condition should be evaluated and treated if needed before providing methods based on cervical secretions. |
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Table F1. Fertility awareness–based methods, including symptoms-based and calendar-based methods
| Condition |
Category |
Clarification/Evidence/Comment |
| Symptoms-based method |
Calendar-based method |
| Other |
| Use of drugs that affect cycle regularity, hormones, or fertility signs |
Caution /Delay |
Caution/Delay |
Clarification: Use of certain mood-altering drugs (e.g., lithium, tricyclic antidepressants, and antianxiety therapies), as well as certain antibiotics and anti-inflammatory drugs, might alter cycle regularity or affect fertility signs. The condition should be carefully evaluated and a barrier method offered until the degree of effect has been determined or the drug is no longer being used. |
Diseases that elevate
body temperature |
| a. Chronic diseases |
Caution |
Accept |
Clarification: Elevated temperatures might make basal body temperature difficult to interpret but have no effect on cervical secretions. Thus, use of a method that relies on temperature should be delayed until the acute febrile disease abates. Temperature-based methods are not appropriate for persons with chronically elevated temperatures. In addition, certain chronic diseases interfere with cycle regularity, making calendar-based methods difficult to interpret. |
| b. Acute diseases |
Delay |
Accept |
Abbreviations: FAB = fertility awareness–based; NA = not applicable.
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