Natural Family Planning BRIAN A. SMOLEY, CDR, MC, USN, Camp Pendleton, California CHRISTA M. ROBINSON, LCDR, MC, USN, Naval Hospital Lemoore, Lemoore Station, California Natural family planning methods provide a unique option for committed couples. Advantages include the lack of medical adverse effects and the opportunity for participants to learn about reproduction. Modern methods of natural family planning involve observation of biologic markers to identify fertile days in a woman’s reproductive cycle. The timing of intercourse can be planned to achieve or avoid pregnancy based on the identified fertile period. The current evidence for effectiveness of natural family planning methods is limited to lower-quality clini- cal trials without control groups. Nevertheless, perfect use of these methods is reported to be at least 95 percent effective in preventing pregnancy. The effectiveness of typical use is 76 percent, which demonstrates that motivation and commitment to the method are essential for success. Depending on the method, couples can learn about natural family planning methods in a sin- gle office visit, through online instruction, or from certified instructors. (Am Fam Physician. 2012;86(10):924-928. Copyright © 2012 American Academy of Family Physicians.) ▲ See related editorials amily planning allows individuals abstinence rather than an artificial contra- at http://www.aafp.org/ and couples to anticipate and attain ceptive method.2-4 afp/2012/1115/od1.html and http://www.aafp. the desired number, spacing, and Although less than 1 percent of respon- 1 org/afp/2012/1115/od2. timing of children. Fertility aware- dents to the 2006-2008 National Survey html. ness methods of family planning use one or of Family Growth reported current use of F ▲ Patient information: more biologic markers to identify fertile days NFP, 19 percent reported prior use of the A handout on natural fam- of a woman’s reproductive cycle. Intercourse rhythm method, and 5 percent reported ily planning, written by the is avoided or a contraceptive method is used prior use of some other NFP method.5 If authors of this article, is on these fertile days to avoid pregnancy. asked for family planning information, one- available at http://www. aafp.org/afp/2012/1115/ Conversely, couples desiring pregnancy are half of physicians report that they would p924-s1.html. Access to more likely to conceive if they have inter- provide information about NFP to prevent the handout is free and course during this fertile period. Fertility pregnancy, and three-fourths would pro- unrestricted. awareness methods qualify as natural family vide information about its use to achieve planning (NFP) if they are used with periodic pregnancy.6 This article discusses methods, mechanisms of action, and demonstrated effectiveness of NFP to enable physicians to provide appropriate information and coun- Table 1. Natural Family Planning Methods seling to their patients. Method Description Methods and Mechanisms of Action Basal body Identifies the luteal phase of the menstrual The five principal types of NFP are calen- temperature cycle by postovulatory increase in basal body dar calculation, basal body temperature charting temperature; all other days are considered fertile charting, cervical mucus monitoring, the Calendar calculation Predicts the fertile period by menstrual dating symptothermal method, and lactational Cervical mucus Identifies beginning and end of the fertile period amenorrhea4 (Table 1). The first four meth- monitoring from cervical secretions ods allow couples to plan intercourse around Lactational Maximizes suppression of ovulation during the days of increased fertility during the amenorrhea breastfeeding; effectiveness limited to six months postpartum woman’s reproductive cycle. In lactational Symptothermal Based on cervical mucus monitoring; calendar amenorrhea, ovulation does not occur, and method calculations or basal body temperature charting there are no fertile days. Use of this method monitoring provides redundancy is limited to women who are exclusively breastfeeding during the first six months Downloaded from the American Family Physician Web site at www.aafp.org/afp. Copyright © 2012 American Academy of Family Physicians. For the private, noncommer- 924 Americancial use of oneFamily individual Physician user of the Web site. All other rights reserved.www.aafp.org/afp Contact [email protected] for copyrightVolume questions 86, Number and/or permission10 ◆ November requests. 15, 2012 Natural Family Planning SORT: KEY RECOMMENDATIONS FOR PRACTICE Evidence Clinical recommendation rating References Lactational amenorrhea is 92 to 100 percent effective in preventing B 7 pregnancy during the first six months postpartum in women who exclusively breastfeed their infants, provided that menstruation does not resume. With perfect use, modern natural family planning methods can be as B 16, 20-23, effective in preventing pregnancy as hormonal contraceptives. 25, 28-30 The Creighton Model for cervical mucus monitoring and the B 16, 22-24 symptothermal method are the most effective natural family planning methods currently available. A = consistent, good-quality patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evi- dence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, go to http://www.aafp.org/afpsort.xml. postpartum, and applies only if menstrua- with a perfectly consistent 28-day cycle, the tion has not resumed. When these conditions rhythm method predicts an eight-day fertile are met, lactational amenorrhea has been period from days 10 through 17. Variations shown to be 92 to 100 percent effective.4,7 in cycle length increase the length of the pre- Identification of the fertile period is the dicted fertile period.3,4,9 The Standard Days central focus of most NFP methods. In the Method is a simplified calendar method days leading up to ovulation, estradiol from that assumes a cycle length of 26 to 32 days the maturing follicles stimulates the section and sets a 12-day fertile period from days 8 of thin, stretchy, watery mucus in the cervi- through 19.10 cal canal that facilitates sperm entry into the upper reproductive tract. Sperm can remain BASAL BODY TEMPERATURE CHARTING viable there for up to five days. Sperm entry Basal body temperature charting takes is inhibited after ovulation by the secretion advantage of the increase in a woman’s tem- of thick, sticky cervical mucus stimulated by perature that occurs during the luteal phase increasing progesterone levels. The ovum is of the reproductive cycle. An increase of at capable of being fertilized for up to 24 hours least 0.4°F (0.2°C) above the baseline tem- after ovulation. The usual viability periods perature recorded early in the of sperm and ovum generate an average six- morning at the same time each Cervical mucus monitoring day fertile period that has been verified by day indicates that ovulation tracks cyclical changes in empiric studies.2,3,8 has occurred. This increase the amount or consistency is monitored over three con- CALENDAR CALCULATIONS secutive days, at which point of cervical secretions. Calendar methods of NFP are based on the fertile period is consid- the relative consistency in the length of the ered over. Because basal body temperature luteal phase of the reproductive cycle. The charting does not identify the beginning of rhythm method is the oldest NFP technique. the fertile period, it is of limited use. Cou- The length of past cycles is used to predict ples who desire pregnancy must use histori- the fertile period in the current cycle. The cal data to predict the next fertile period. beginning of the fertile period is calculated Couples trying to avoid pregnancy must by subtracting 18 days from the shortest of restrict intercourse to the luteal phase of the previous six to 12 cycles. The end of the the cycle.3,4,9 Basal body temperature chart- fertile period is calculated by subtracting 11 ing is typically used in combination with days from the longest cycle. For a woman other methods. November 15, 2012 ◆ Volume 86, Number 10 www.aafp.org/afp American Family Physician 925 Natural Family Planning CERVICAL MUCUS MONITORING questions: “Did I note secretions today?” Cervical mucus monitoring has become and “Did I note secretions yesterday?” If a the basis for most modern NFP methods. woman answers “yes” to either question, she These methods allow users to identify the is considered fertile.14 beginning and end of the fertile period by recognizing cyclical changes in the amount SYMPTOTHERMAL METHOD or consistency of cervical secretions. The The symptothermal method combines cal- Billings Ovulation Method, Creighton endar calculations, basal body temperature Model, and TwoDay Method are different charting, and cervical mucus monitoring. systems for observing cervical secretions Cervical secretions are the foundation for and using them as markers of fertility. The this method, and the other techniques pro- oldest of the three, the Billings Ovulation vide a “double-check.” Women may use Method, is taught worldwide, and instruc- other signs (e.g., consistency and position of tions are available online.11,12 The Creigh- the cervix) or symptoms (e.g., breast tender- ton Model is a standardized modification of ness, ovulatory pain) to aid in the identifica- the Billings Ovulation Method taught and tion of the fertile period.15,16 The Marquette personalized for couples over multiple ses- Model combines the use of an electronic sions.13 The TwoDay Method reduces the hormonal fertility monitor to detect metab- interpretation of cervical secretions to two olites of estrogen and luteinizing hormone in the urine with observation of cervical secre- tions or basal body temperature charting to Table 2. Effectiveness of Natural Family Planning identify the fertile period.2,17 Compared with Other Family Planning Methods Effectiveness of Modern NFP Methods Percentage of women with The effectiveness of family planning meth- an unintended pregnancy ods is measured for perfect and typical within the first year of use use.