Fertility Awareness-Based Methods: Another Option for Family

CLINICAL REVIEW

Fertility Awareness-Based Methods: Another Option

for Family Planning

Stephen R. Pallone, MD, and George R. Bergus, MD

Modern fertility awareness-based methods (FABMs) of family planning have been offered as alternative

methods of family planning. Billings Ovulation Method, the Creighton Model, and the Symptothermal

Method are the more widely used FABMs and can be more narrowly deﬁned as natural family planning.

The ﬁrst 2 methods are based on the examination of cervical secretions to assess fertility. The Sympto-

thermal Method combines characteristics of cervical secretions, basal body temperature, and historical

cycle data to determine fertility. FABMs also include the more recently developed Standard Days Method

and TwoDays Method. All are distinct from the more traditional rhythm and basal body temperature

methods alone. Although these older methods are not highly effective, modern FABMs have typical-use

unintended pregnancy rates of 1% to 3% in both industrialized and nonindustrialized nations. Studies

suggest that in the United States physician knowledge of FABMs is frequently incomplete. We review the

available evidence about the effectiveness for preventing unintended pregnancy, prognostic social de-

mographics of users of the methods, and social outcomes related to FABMs, all of which suggest that

family physicians can offer modern FABMs as effective means of family planning. We also provide sug-

gestions about useful educational and instructional resources for family physicians and their patients.

(J Am Board Fam Med 2009;22:147–157.)

Fertility awareness-based methods (FABMs) of

family planning are methods that use physical signs

and symptoms that change with hormone ﬂuctua-

tions throughout a woman’s menstrual cycle to

predict a woman’s fertility. The unifying theme of

FABMs is that a woman can reduce her chance of

pregnancy by abstaining from coitus or using bar-

rier methods during times of fertility. Natural fam-

ily planning (NFP) is a subset of FABMs that spe-

ciﬁcally excludes concurrent use of all other forms

of contraception, including barriers, as a supple-

ment to the observation for fertile signs; pregnancy

is avoided through abstinence alone.

Several factors contribute to a woman’s fertility.

An ovum survives up to 24 hours after ovulation

unless it is fertilized, leaving a ﬁnite time for sperm

to reach the egg. Sperm have short life spans after

ejaculation without hospitable cervical mucous,

which is present only in the periovulatory period.

In optimum conditions, the typical maximum life

span of sperm is 5 days, leaving a fertile window of

approximately 6 days.

2,3

Although FABMs may be

used to achieve pregnancy, that discussion is be-

yond the scope of this review.

FABMs are diverse. They include the older cal-

endar (“rhythm”)- and basal body temperature-

based methods and the newer methods that assess

cervical mucous or a combination of signs and

symptoms (which include the older methods). The

former are generally not considered to be highly

effective.

The newer methods compare favorably

with conventional contraceptives (Tables 1 and 2).

It is not certain where providers and patients obtain

their information about FABMs. Anecdotal evi-

dence suggests that in the United States instruction

is not often available through physician providers,

occasionally through hospital programs, and more

often available from faith-based groups.

When provided with positive information about

FABMs more than 1 in 5 women in the United

This article was externally peer reviewed.

Submitted 11 February 2008; revised 26 August 2008;

accepted 8 September 2008.

From the Departments of Family Medicine and Psychia-

try, University of Iowa, Iowa City.

Funding: none.

Conﬂict of interest: none declared.

Corresponding author: Stephen R. Pallone, MD, Depart-

ment of Family Medicine and Psychiatry, University of

Iowa, 200 Hawkins Drive, 01105 PFP, Iowa City, Iowa

52242-1097 (E-mail: [email protected]).

doi: 10.3122/jabfm.2009.02.080038 Fertility Awareness-Based Family Planning 147

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States expressed interest in using one of these

methods to avoid pregnancy.

36,37

However, only

1% to 3% percent of US women are currently

using an FABM for this purpose.

36,38

Despite an

improved understanding of the science underlying

FABMs, rates of use have declined to 11% from

22% of married couples in 1955.

37,39

This decline

is multifactorial. Clinicians and patients frequently

perceive a difﬁculty in learning the methods.

36,40,41

Many women also believe FABM are not efﬁca-

cious.

36,40,41

Many physicians do not have the

knowledge to teach their patients about these

methods. One geographically limited study found

that physicians have signiﬁcant knowledge deﬁcits

about FABMs

and that they generally know less

about these methods than do nurse midwives.

Another survey of NFP users showed that only 1%

of them came to use those methods because of the

advice of medical practitioners.

Outcomes

There has been considerable debate about the

soundness of the research on FABMs’ effectiveness.

Some research methods make comparison between

FABMs and other contraceptive methods difﬁcult.

There are few randomized controlled studies of

FABMs; existing randomized trials were judged to

be of insufﬁcient quality to draw any valid conclu-

sions.

Many recent studies of modern FABMs

included only self-selected patients, which is more

consistent with clinical practice.

5,11

Early FABM

investigations usually excluded data from the

“learning phase” (typically 3 cycles), skewing the

data in favor of FABMs. More recent studies in-

clude this period in their data.

5,11

In addition, FABMs are unique in that they can

also be used for achieving pregnancy. Pregnancy

rates are therefore reported in categories of per-

fect-use (method-related) pregnancies, achieving-

Table 1. Conventional Birth Control: Method and User Effectiveness Rates

Method

Women with Unintended Pregnancy

Within 1 Year of Use (%)

Women Continuing Use at 1 Year (%)Typical Use Perfect Use

None 85 85

Spermicide 29 18 42

Withdrawal 27 4 43

Cervical cap

Parous 32 26 46

Nulliparous 16 9 57

Sponge

Parous 32 20 46

Nulliparous 16 9 57

Diaphragm 16 6 57

Condom

Male 15 2 53

Female 21 5 49

Combined pill and minipill 8 0.3 68

Evra patch 8 0.3 68

NuvaRing 8 0.3 68

Depo-Provera 3 0.3 56

Lunelle 3 0.05 56

Intrauterine device

Copper T 0.8 0.6 78

Mirena 0.1 0.1 81

Norplant and Norplant-2 0.05 0.05 84

Female sterilization 0.5 0.5 100

Male sterilization 0.15 0.10 100

Reproduced with permission from Hatcher R, Trussell J, Stewart F, et al. Contraceptive Technology 18

ed. Ardent Media, Inc, New

York, NY, 2004.

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related pregnancies, and typical-use pregnancies.

The achieving category allows for the proper clas-

siﬁcation of women who change their minds mid-

cycle about wanting to avoid pregnancy; they

would be labeled as typical-use pregnancies in con-

traceptive trials that categorize women based on

their decision to avoid pregnancy at the beginning

of each cycle. On the other hand, the achieving

category includes women who engage in coitus at a

time when they know they are fertile even if their

intention is to avoid pregnancy. Recent FABM

studies typically report all 3 of these categories,

with some variation in the achieving-related cate-

gory. The 2 most useful for comparison are the

perfect-use and typical-use pregnancy rates.

There have been attempts to characterize

women who are successful (likely to persist in using

the methods as described) with FABMs; however,

no consistent positive predictors across studies have

been found.

45,46

Successful use is probably deter

mined in part by societal attitudes regarding sexual

behavior and sexuality, religious beliefs, and per-

sonal characteristics of the woman choosing to use

them, such as interest in alternative medicine and

the support of her partner. Most studies of FABMs

included predominantly women who are in long-

term and stable relationships. Most users of

FABMs in US studies have been Roman Catholic,

in a long-standing committed relationship, white,

have a high school education or higher and a gross

income more than $20,000 per year.

9,46

Although

uncommonly used in the United States, as many as

20% of married women in other countries use one

of these methods.

The lowest pregnancy rates associated with

FABMs are achieved by women who choose to use

these methods and have been properly instructed in

how to do so. International studies suggest poverty-

Table 2. Fertility Awareness-Based Methods Based on Life Table Analysis

4–35

Method

Women with Unintended Pregnancy

Within 1 Year of Use (%)

Women

Continuing Use

at 1 Year (%)

Women with

Unintended Pregnancy

Caused by

Unprotected

Intercourse on Days

Known Fertile Days

(%)Typical Use

With Barrier

Backup* Perfect Use

Calendar

Rhythm

†

25 0.1–9

Standard days

‡

12 5.7 4.8 46

7.8

Basal body temperature 1

Cervical mucous

TwoDays 13.7 6.3 3.5 52.7

㛳

7.3

Billings Ovulation

10.5–22.3 NT 0.5 30.4–99.5 15.4

Creighton/NaProEducation

Technology

17.1** NT 0.5 79.8–88.7 12.8

Symptothermal

0.2–20

††

0.45–2.3* 0.3 51.7–92.5 8.96

Lactational amennorrhea

‡‡

2NA NA

*Fertility awareness-based methods deﬁned more speciﬁcally as natural family planning do not report this data because it is considered

abandonment of the method. Data is included where available.

†

Estimated (deﬁnitive data not available).

‡

Limited to women with ⬍2 cycles in 1 year outside of the 26- to 32-day range.

Twenty-eight percent discontinued because of 2 cycles outside 26- to 32-day range or 1 cycle longer than 42 days.

㛳

Because of secretions ⬎14 days or cycles ⬍5 days (these are indicators of other potential health concerns), 15.7% asked to leave by

study protocol. This loss also included women with cycles ⬎42 days (n ⫽ 30) because of the cost of follow-up as well as women who

failed to log symptoms for at least 12 cycles (n ⫽ 12).

Typical use variable by study. More recent international studies show progressively lower unintended pregnancy rates and higher

continuation rates.

**Overall pregnancy rate. Studies included women wishing to achieve pregnancy and made no attempt to distinguish planned vs

unplanned pregnancies. Pregnancies resulting from intercourse on days known to the couple as fertile were counted as achieving

related. Avoiding related pregnancies were 3.2% overall.

††

Lower typical failure rate with double-check method compared with single-check method.

‡‡

Perfect-use rate is for ﬁrst 6 months only. LAM is ineffective as birth control if not used properly.

NT, not taught; NA, not applicable; LAM, Lactational Amennorrhea Method.

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stricken populations have lower rates of typical-use

pregnancy when using FABMs, in some cases ap-

proaching 0%.

5,12

Poverty may be a signiﬁcant mo

tivator for successful FABM use because the cost of

raising a child is high and access to conventional

contraceptives is limited.

However, studies in the

United Kingdom, Italy, and Germany report sim-

ilarly low rates of pregnancy,

13–16

even in younger

unmarried populations.

Some international stud

ies have also included women of diverse religions

(including Hindus, Muslims, and Buddhists); races;

and socioeconomic status. The success of these

other demographic groups coupled with insufﬁ-

cient knowledge about FABMs in the medical com-

munity in the United States suggests American

white, upper-middle class, and Catholic women are

more likely to use FABMs in part because they have

more access to information about these methods.

Lack of support from the husband and physical

separation of the partners are thought to be pre-

dictors of FABM failure or discontinuation.

Rea

sons for discontinuation of some FABMs are sum-

marized in Table 3.

All FABMs are physiologically compatible with

the use of barrier methods. Use of barriers during

fertile periods reduces the overall undesired preg-

nancy rate with typical use of the Standard Days

and TwoDays methods but also increases perfect-

use pregnancies.

10,21

Conversely, studies examining

symptothermal methods have shown no signiﬁcant

differences in method- and typical-use pregnancies

with or without use of barriers while still maintain-

ing low unintended pregnancy rates.

19,20,49

NFP

methods stress that the use of barriers is abandon-

ment of the method.

26,50,51

Beneﬁts and Harms

The lack of medical side effects and the low cost of

FABMs are implicit beneﬁts, but the social effects

deserve some examination. Modern NFP methods

are associated with a lower incidence of induced

abortion.

43,45

They are also associated with a US

divorce rate lower than that among the general US

population.

One nonrandomized survey found

the ever-divorced rate among NFP users was 2 in

1000 if they had never used other forms of contra-

ception. Four percent of those who had used non-

NFP types of contraception previously had been

divorced.

In the same year, 10.8% of the general

population identiﬁed themselves as presently di-

vorced, with a divorce rate of 4.1 in 1000 per

Table 3. Percentage of Original Study Group Discontinuing Various Fertility Awareness-Based Methods at 12

Months or 13 Cycles by Study

6,10,11,21

Reason SDM (%) TDM (%) CrM (%) BOM (%)

Completed study 45.6 52.7 — —

Eliminated by study protocol 28.0 15.7 — —

Told risk of pregnancy would be high 0.2 — — —

Did not like the method 0.2 1.8 0.7 —

Did not trust the method 1.7 1.8 0.7 —

Partner did not like the method 2.1 2.0 0.7 3.0*

Planning pregnancy 2.1 2.2 — 5.0*

To use other FABM — — 0.7 —

To use artiﬁcial method — — 4.5 20.1*

Difﬁculty avoiding genital contact — — 0.7 —

Other voluntary reason 4.0 10.4 4.6 1.0*

Lost to follow up 7.1 4.4 — 16.3*

Pregnancy 9.0 10.4 —

†

16.0*

Medically induced infertility — — 0.3 —

Unknown — 0.2 — —

Data not reliably available for Rhythm, Basal Body Temperature, and Symptothermal methods.

*Billings Ovulation Method–India trial: data reported at 21 ordinal months. Overall discontinuation rate at 12 months was 24%.

Individual reasons were not reported for this time frame.

†

Creighton Model did not remove participants from study for pregnancy because studies were designed to evaluate both pregnancy-

achieving and pregnancy-avoiding behaviors.

SDM, Standard Days Method; TDM, TwoDays Method; CrM, Creighton Model; BOM: Billings Ovulation Method, —, data not

available.

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year.

52,53

Catholics who do not use NFP have di

vorce rates similar to those of the general popula-

tion, suggesting that religion alone does not ac-

count for this difference.

The difference may be

attributable to the methods or to selection bias,

although neither has been clearly established.

These effects have not been studied in FABMs.

Proponents of modern NFP often endorse im-

proved communication, sexual interactions, deeper

intimacy and respect for partners, and other aspects

of psychosocial–spiritual well-being with NFP use.

Evidence is insufﬁcient to evaluate this claim,

which is based on a single nonrandomized survey of

NFP users.

Subsequent conﬁrmation studies ex

amining well-being have methodological ﬂaws,

such as incomplete reporting of data and mis-

matched comparison groups, making it difﬁcult to

assess the validity of these statements on a popula-

tion level.

54,55

Most couples continuing to use NFP

have mixed feelings about the methods, but re-

sponses are primarily positive.

These effect have

not been studied in FABMs.

Another concern voiced about FABMs is the

potential for decreased frequency of intercourse.

Studies have found that coital frequency varies

greatly by country, ranging from 2.6 to 8.9 acts per

month; the worldwide average is approximately 5.5

acts per month among all couples. FABM users

have an average monthly coital frequency of 5.1

acts per month.

Standard Days Method (SDM)

and TwoDays Method (TDM) users average 5.5

and 5.6 acts per month, respectively.

The timing

of intercourse does shift with the use of FABMs,

becoming more frequent during identiﬁed nonfer-

tile days. There is a small trend of increased fre-

quency of intercourse as the users become more

comfortable with their chosen method.

Although

perceived lack of spontaneity of intercourse is

raised as a concern related to FABM use, this aspect

of FABMs has not been adequately studied.

Calendar Methods

The Rhythm Method (RM), introduced in the

1920s before the availability of hormonal methods

of contraception, was the ﬁrst FABM. At its incep-

tion, it was believed to be one of the most effective

methods of birth control.

4,59

The effectiveness of

RM has never been precisely determined. The few

existing RM studies used different rules about when

not to have intercourse or did not report these

rules.

Studies of RM often included individuals

who reported using intercourse rules inconsistent

with any validated calendar method.

45,60

It is not

clear whether this misuse of the method came from

a lack of formal information, lack of proper instruc-

tion, or whether the instructions were difﬁcult to

understand.

One type of traditional RM is practiced by count-

ing days in a cycle, with the beginning of menstrua-

tion being day 1 for each cycle. Days 12 to 19 (inclu-

sive) are considered fertile. The difference between

the longest and shortest of the previous 8 to 12 cycles

are subsequently added as additional fertile days at the

beginning of the fertile time. This method was ini-

tially reported to be so effective that there were no

pregnancies for more than 54,000 acts of coitus when

the method was used properly.

61,62

A meta-analysis

later reported total unplanned pregnancy rates of

15% to 18.3%.

Effective use of the RM is hindered by events

that affect the length and regularity of the men-

strual cycle, including the use of hormonal contra-

ceptives, recent pregnancies or childbirth, breast-

feeding, menarche or menopause, inherent cycle

variation, or illness. More pregnancies result when

cycles are irregular. RM typically overestimates the

fertile period, and accurate history of the menstrual

cycles of the previous 8 to 12 months is necessary

for use of the method. Without data about past

cycles it is not considered reliable for avoiding

pregnancy.

One modern user-friendly calendar method is

the SDM. It is applicable for women with cycles

consistently between 26 and 32 days (inclusive). It

differs from previous calendar methods in that his-

torical data are not needed to calculate the fertile

window. Days 8 to 19 (inclusive) are considered

fertile for all users of this method. Two or more

cycles outside of the 26- to 32-day range within 1

year contraindicate SDM use, which excluded 28%

of the original sample from further participation in

the study.

Color-coded cycle beads, essential to

SDM practice, help with tracking fertile and infer-

tile days and are available for $12 per a kit, includ-

ing instructions. Use of SDM is also limited during

variable menstrual cycles.

Basal Body Termperature

Basal body temperature (BBT) elevation, another

older method, retrospectively identiﬁes fertility.

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The luteinizing hormone surge, which stimulates

ovulation, is associated with a 0.5- to 1°F- (0.3- to

0.6°C-) rise in BBT measured with highly stan-

dardized methods. BBT can be taken orally, vagi-

nally, or rectally with a sensitive thermometer; the

same site should be used daily. BBT is measured on

awakening at approximately the same time every

morning, before getting out of bed or doing any

other activity. At least 6 hours of uninterrupted

sleep the preceding night is necessary for accurate

measurement. BBT remains elevated throughout

the luteal phase secondary to higher progesterone

levels. The woman is assumed to have ovulated

after observing 3 consecutive days of temperature

elevation. Pregnancy is avoided by abstaining from

the beginning of menstruation until 3 to 4 days

after the rise in BBT. All subsequent days until the

beginning of her next menses are considered infer-

tile.

Because sperm survive 5 days, BBT alone does

not predict ovulation far enough in advance to

identify all the potentially fertile days; it predicts

only peak fertility, so thus the need to abstain

from the beginning of menstruation. Many other

factors also limit the use of BBT. Some women

ovulate without a clear rise in BBT.

Alcohol

consumption, late nights or oversleeping, dis-

rupted sleep, travel, time zone differences, holi-

days, shift work, stress, illness, gynecologic dis-

orders and medications can all lead to inaccurate

basal temperature measurement.

Moreover, the

biphasic shift of BBT has been found to vary up

to 1 day before and 3 days after actual ovula-

tion.

22,63

Extensive reviews of BBT have been

conducted elsewhere.

4,23,24

Cervical Secretion Methods

Studies have found cervical secretion characteristics

to be highly predictive of ovulation and can there-

fore be used to avoid pregnancy.

64,65

Studies con

ducted by the World Health Organization indicate

that 93% of women, regardless of their education

level, are capable of identifying and distinguishing

fertile and infertile cervical secretions.

Three main cervical secretion methods exist

and are described below. All the methods involve

noting the presence or absence of cervical secre-

tions, usually recommended to be checked both

at midday and early evening when women are less

likely to have sex. Women are further asked to

characterize the secretions as to color, texture,

and stretch, the detail depending on the method

of instruction. Fertile cervical secretions are

clear, wet, slippery, stretching and changing in

quality. They are often compared with egg

whites. Infertile secretions are unchanging and

generally dry, sticky, cloudy, and do not stretch.

Menstruation is considered fertile because men-

ses can mask the signs of cervical secretion, as can

sexual ﬂuids. Therefore, a day of abstinence after

coitus occurring between menstruation and ovu-

lation is required to interpret secretion signs.

Hence, every other day between menstruation

and the onset of the fertile phase is available for

intercourse. One identiﬁes peak fertility retro-

spectively when fertile secretions begin to return

to a basic infertile pattern. It is safe to have

intercourse without restrictions on the fourth day

after peak fertility until the onset of the next

menses. Any bleeding or cervical changes that

interrupt the basic infertile pattern are poten-

tially fertile.

50,51

The Billings Ovulation Method (BOM) was the

ﬁrst described and allows women to describe secre-

tions “in their own words” with a focus on changes

in cervical characteristics. It has undergone reﬁne-

ment since studied in the United States.

5,50

In a

study undertaken in India, pregnancy rates among

perfect and all users of this method were 1.1% and

2% to 10.5%, respectively, at 12 months.

5,6

In the

US study (1975 to 1977), method- and typical-use

pregnancies were 1% and 16%, respectively.

The

World Health Organization study of 1981 calcu-

lated typical-use pregnancies of 22.3%, with 15.4%

caused by a conscious departure from method

rules.

A randomized trial in China reported typ

ical-use pregnancy with BOM as 0.5% when used

to avoid pregnancy and had higher adherence than

the copper intrauterine device to which it was com-

pared. However, the data has not been published

for peer review in English and the BOM Associa-

tion reports that women unable to identify fertile

cervical secretions were excluded.

Discontinua

tion rates were 0.5% and 24% at 12 months in

China and India, respectively, and 44% at 2 years in

the United States.

5,6,25

A distinct method, the Creighton Model (CrM),

also called NaProTechnology, is more standard-

ized in the way secretions are characterized, using

pictures and precise words to describe them.

8,9,51

The male partner is responsible for charting and

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interpreting the data, a step supporters believe en-

courages sharing responsibility for family planning

and facilitates communication and relationship

building. The effectiveness of the CrM has im-

proved since its introduction in 1980, presumably

because of improved methods of instruction.

8,9

CrM instructors must be certiﬁed in a year-long

program accredited by the American Academy of

Natural Family Planning and are asked not to pre-

scribe other forms of birth control. Standardized

patient instruction involves 8 one-hour sessions

over the course of 1 year, 5 of them in the ﬁrst 3

months.

CrM users are instructed that conscious

departure from the method rules resulting in inter-

course on method-predicted fertile days implies

that they are no longer using the method for avoid-

ing pregnancy but for achieving pregnancy. All

pregnancies resulting from such actions are thus

classiﬁed as achieving-related pregnancies without

distinguishing between intended or unintended

pregnancies. Although the argument of classifying

pregnancies based on the “objective behavior of the

patient” has merit, it is inconsistent with the ma-

jority of other family planning investigational

methods, which would report some of these preg-

nancies as unintended or unplanned. CrM studies

are “in vivo” and include women who are not trying

to avoid pregnancy. Comparison of the typical use

of CrM to other methods is therefore difﬁcult, and

reported data of overall pregnancies is probably an

overestimate of unintended pregnancies. Method-

related pregnancies, however, are comparably re-

ported.

8,9

The TDM is a simpler method that can be

taught during a routine ofﬁce visit. The woman is

taught to identify cervical secretions of any type

regardless of their characteristics. She then is in-

structed to ask herself, “Did I notice any cervical

secretions today?” If the answer is no, she then asks,

“Did I notice any cervical secretions yesterday?” If

the answer is no, then intercourse is unlikely to

result in pregnancy. If the answer to either of the 2

questions is “yes,” then intercourse has a high

probability of resulting in a pregnancy. The same

preovulatory cervical secretion check rules de-

scribed above apply. There are no restrictions on

coitus when cervical secretions meet the 2-days rule

after peak fertility and until the onset of the next

menstruation.

10,68

All cervical methods are theoretically compati-

ble with cycles of any length and variable hormonal

states. However, they have not been studied in

depth because of the expense of following women

with longer cycles and medical concerns with

shorter cycles.

10,50,51

Symptothermal Method

The Symptothermal Method combines BBT, cer-

vical methods, cervical position, and/or historical

cycle data to prospectively and retrospectively

identify the peri-ovulatory period. In its most ef-

fective form, 2 signs are used to “double check”

each phase as conﬁrmation for the couple that the

woman is unlikely to be fertile.

20,26

The method

has a 0.4% pregnancy rate when used as de-

scribed.

4,14

Typical-use unplanned pregnancy rates have

been reported as low as 1% to 3% in Europe and

India.

7,12–16,19,20

However, unplanned pregnancy

rates as high as 13% to 20% have also been re-

ported for typical users of the Symptothermal

Method.

Critics warn that combining signs and

symptoms can overestimate the fertile phases by a

couple of days or more. On the other hand, because

there is no requirement to abstain every other day

before the fertile phase, the total abstinence time is

approximately equivalent to cervical secretion

methods. There is a trend of increased intercourse

among couples who use barrier back-up methods

concurrently. This trend, however, may be con-

founded because women using barrier backup are

generally younger.

Breast Feeding

Lactational amenorrhea results in a 2% pregnancy

rate when used under 3 conditions. The ﬁrst is that

the lactating woman is supplying at least 90% of

the infant’s calories through breastfeeding at inter-

vals no longer than every 4 hours during the day

and every 6 hours at night, but ideally more fre-

quently. Second, she has not resumed her menses.

Third, she is in the ﬁrst 6 months postpartum. Such

women may not need additional contraception,

therefore avoiding the controversy of taking hor-

mones while breastfeeding.

4,27–33

The pregnancy

rate increases to 5% in working women even if they

express their milk every 4 hours, suggesting that

the suckling of the infant contributes substantially

to the contraceptive effect.

4,34

Beyond 6 months,

the likelihood of ovulation preceding menses in-

doi: 10.3122/jabfm.2009.02.080038 Fertility Awareness-Based Family Planning 153

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creases with time, raising the probability of con-

ception.

The low pregnancy rate of lactational amenor-

rhea, in addition to the many other beneﬁts of

breastfeeding, may be another reason for women to

consider strict breastfeeding. Cultural and work-

related constraints may be barriers inhibiting more

widespread use of the method. Women not want-

ing to conceive again or with regimented spacing

ideas need adequate education to identify signs of

returning fertility (mainly more than 6 months

postpartum, return of menses, or supplementation

of the infant’s calories from sources other than

maternal breast milk) so that they are prepared to

switch to another method without delay. Modern

FABMs, with the exception of SDM, are appropri-

ate for this purpose.

21,62

Fertility Awareness-Based Instruction and

Resources

The SDM and TDM are conducive to physician

ofﬁce-based instruction because they are simple to

teach and ordinarily can be taught during a stan-

dard 15-minute clinic appointment. Information

about instruction or becoming a certiﬁed instructor

in FABMs/NFP can be found through the method

speciﬁc web sites (Table 4); many of these are

faith-based groups. Some practices employ a

teacher to whom they can refer patients. Additional

courses are often offered through local churches,

particularly if they are Catholic, and can sometimes

be found at local hospitals.

Conclusion

The available evidence suggests that FABMs, based

largely on assessing cervical mucous, can provide

effective contraception. Although these methods

have not gained wide use, modern FABMs can be

mastered by most motivated couples. Physicians’

and other medical personnel’s limited knowledge of

and experience with the methods inhibits broader

use. Physicians should offer FABMs as a reasonable

choice for family planning because there are no

absolute contraindications. A woman’s informed

decision to use such methods should be supported

with accurate information and referral to a certiﬁed

provider. Instruction is available in many commu-

Table 4. Educational and Instructional Resources for Fertility Awareness-Based Methods

Organization Website

Book/Home/Online

Course Method

Georgetown Institute

of Reproductive

Health

http://www.irh.org Refer to website Standard Days and

TwoDays Methods

Couple to Couple

League

International

http://ccli.org The CCL Home Study

Course, ⬃$75

Symptothermal

Method

The Billings

Ovulation Method

Association

http://www.boma-usa.org The Billings Method,

⬃$20

Billings Ovulation

Method

American Academy of

FertilityCare

Professionals

http://www.aafcp.org Refer to website Creighton Model

One More Soul http://www.omsoul.com Search for providers of

multiple methods

Marquette University

Institute for

Natural Family

Planning

http://www.marquette.edu/nursing/NFP/Model.shtml Marquette Model*

Northwest Family

Services

http://www.nwfs.org/nfp.htm Refer to website Symptothermal

Method*

Family of the

Americas

Foundation

http://www.familyplanning.net Ovulation Method*

Information from reference cited above and indicated websites.

*Not speciﬁcally discussed in the text.

CCL, Couple to Couple League.

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nities and from online courses. Some of these

methods can be taught during a single session.

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