Based Methods of Family Planning to Breastfeeding Women
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FERTILITY AND STERILITY VOL. 80, NO. 5, NOVEMBER 2003 Copyright ©2003 American Society for Reproductive Medicine Published by Elsevier Inc. Printed on acid-free paper in U.S.A. Application of simple fertility awareness– based methods of family planning to breastfeeding women Marcos Are´ valo, M.D., Victoria Jennings, Ph.D., and Irit Sinai, Ph.D. Institute for Reproductive Health, Georgetown University, Washington, D.C. Objective: To determine the potential efficacy of two simple fertility awareness–based methods of family planning—the Standard Days Method™ and the TwoDay Method™—among breastfeeding women. Design: Analysis of pre-existing data set, collected in 1986–1990. Setting: Pre-existing data from Australia, Britain, and Canada. Patient(s): Seventy-three breastfeeding women in Australia, Britain, and Canada, who were followed starting 42 days postpartum, until they had at least two potentially fertile cycles (defined as cycles with adequate levels of urinary estrogens (E) and pregnanediol glucuronide and a long enough luteal phase to support a pregnancy). Received February 3, 2003; We examine this existing data set. revised and accepted April Intervention(s): None. 14, 2003. Main Outcome Measure(s): Probability of pregnancy from intercourse on different days of the cycle relative Supported by the Institute to ovulation for breastfeeding women following the instructions of the Standard Days Method or the TwoDay for Reproductive Health, Georgetown University, Method. under a cooperative Result(s): These two methods may be appropriate for different groups of breastfeeding women at different agreement HRN-A-00-97- times. The Standard Days Method may be appropriate after cycle regularity is established, whereas the 00011-00 with the United TwoDay Method may be a more effective option earlier in the postpartum period. States Agency for International Development. Conclusion: A need remains for a more appropriate simple fertility awareness–based method during this early The Family Health period. (Fertil Steril 2003;80:1241–8. ©2003 by American Society for Reproductive Medicine.) International study was Key Words: Standard Days Method, TwoDay Method, contraceptive efficacy, fertility awareness, breast- supported by the Institute feeding for Reproductive Health, Georgetown University, under its cooperative agreement DPE-3040-A- The potential efficacy of two simple fertility breastfeeding (3). Fertility awareness–based 00-5064-00 with the United awareness–based methods of family plan- methods of family planning may be especially States Agency for ning—the Standard Days Method™ and the useful for breastfeeding women, because they International Development. TwoDay Method™—for breastfeeding women do not affect the nutritional quality or quantity The views expressed by the authors do not were examined. Both methods offer simple but of milk, and do not involve transmission of necessarily reflect the effective guidelines to help women identify exogenous hormones to the infant. views or policies of the their “fertile window”—the days each cycle United States Agency for The Standard Days Method, based on a when they should avoid unprotected inter- International Development, fixed formula defining the fertile window as Family Health International, course to prevent pregnancy. or Georgetown University. days 8–19 of the menstrual cycle, was shown Reprint requests: Marcos Worldwide, significant numbers of women in a clinical trial to have a failure rate of Ͻ5% Are´ valo, M.D., Institute for breastfeed their children (1). Many of these when used correctly by women who were Reproductive Health, Georgetown University, women are particularly vulnerable to preg- screened for potential cycle regularity (4). The 4301 Connecticut Ave., nancy because they often believe that breast- TwoDay Method involves noticing the pres- NW, Suite 310, Washington, DC 20008 feeding protects them from pregnancy. For the ence and absence of cervical secretions. Its (FAX: 202-537-7450; health of the mother and the infant, it is impor- theoretical efficacy for non-breastfeeding E-mail: irhinfo@ tant that she not become pregnant again for at women has been established (5, 6), and a clin- georgetown.edu). least 2.5–3 years, and recent research suggests ical efficacy trial is ongoing. The use of these 0015-0282/03/$30.00 that the ideal birth spacing interval is 3–5 years methods among breastfeeding women has not doi:10.1016/S0015-0282(03) 02184-8 (2). This is particularly important if she is yet been tested. Breastfeeding affects factors 1241 that are central to some fertility-awareness–based methods, breastfeeding and fertility awareness–based methods, above including cervical secretions and cycle length and regularity. and beyond the usual requirements of these methods (15, The current study is designed to assess the potential 16). efficacy of the Standard Days Method and the TwoDay Clearly, breastfeeding women could benefit from a simple Method if used by breastfeeding women. The methods are fertility awareness–based method of family planning, pro- described fully in the Appendix. vided that the method is effective in helping them avoid unplanned pregnancies while they continue to breastfeed. Why Focus on Breastfeeding Women? The purpose of this secondary analysis is to assess the Breastfeeding alters the normal pattern of hormonal theoretical effectiveness of such methods for breastfeeding events in the hypothalamus-hypophysis-ovary axis, resulting women, including those who no longer meet the LAM cri- in suppressed ovarian activity and reduced fertility. There is teria. much evidence that the frequency and duration of breast- feeding episodes are important in suppressing ovulation and lowering the probability of conception (7, 8). Even when MATERIALS AND METHODS ovulation returns, hormonal function often remains dis- The original data were collected by Family Health Inter- rupted, resulting in continuing reduced probability of fertil- national (FHI) from 1986–1990 in a study of the Sympto- ization and implantation (9). Yet, fertility eventually returns, thermal Method, and are reanalyzed here. Data are available and the probability that lactating women will become preg- on 73 breastfeeding women in Australia, Britain, and Can- nant if they have unprotected intercourse increases with ada. The mean age of study participants was 29 years, and time. A significant number of women worldwide breastfeed their average number of live births, 2.3. Education levels their children (1), and many become pregnant when their were slightly higher in Canada and more of the Canadian babies are still very young, endangering the health and lives women had professional occupations and worked outside the of themselves and their children. home, but these differences across the centers were not Efforts to determine the timing of the postpartum return to statistically significant (14). fertility and factors influencing it have led to the develop- Study participants contributed daily information starting ment of the Lactational Amenorrhea Method of family plan- 42 days postpartum, and until they had at least two “normal” ning (LAM). LAM is based on three criteria. For a woman to cycles (defined as cycles with adequate urinary levels of be eligible to use LAM, she should be less than 6 months estrogens (E), pregnanediol glucuronide, and a luteal phase postpartum, amenorrheic, and fully or nearly fully breast- long enough to support a pregnancy) (14). Daily information feeding (10). When women are more than 6 months post- is available on breastfeeding patterns, appearance and char- partum, when their menstruation returns, or when they are no acteristics of cervical secretions, and cycle characteristics longer fully breastfeeding, LAM is no longer considered as such as timing of ovulation, bleeding, and cycle length. effective, and they should use another family planning Ovulation was defined as day of maximum urinary E, method if they wish to avoid pregnancy (11). measured by spectrofluorometry. A cycle was said to have A fertility awareness–based method of family planning is adequate luteinization to support a pregnancy if Ͼ9.0 one possible choice for women who continue to breastfeed moles/24 hours of pregnanediol were measured and there and seek an alternative family planning method that does not was a luteal phase, as measured from the E peak to the day affect milk quality or quantity after they no longer meet the before the next menstruation, of at least 10 days. The cycle LAM criteria. Established fertility awareness–based meth- was considered to have an inadequate luteal phase to support ods, such as the Billings Ovulation Method and the Symp- a pregnancy if there were pregnanediol concentrations of tothermal Method, are applicable, with some modifications, between 4.5 and 8.9 moles/24 hours or if the luteal phase to breastfeeding women (12, 13). was fewer than 10 days. Follicular activity with correspond- Various studies examined their efficacy, concluding that ing pregnanediol concentration of fewer than 4.5 moles/24 these methods can be effective in preventing pregnancy in hours was considered to be anovulatory (14). This definition lactating mothers (14). However, the first cycles postpartum of ovulatory cycles was standard when these data were present additional difficulties for breastfeeding users, be- collected (1986–1990) (17, 18). We recognize that other cause the normal mucus and temperature patterns may not markers of ovulation, such as serum or urinary LH concen- yet be established even after