Efficacy of the symptothermal method of natural family planning in lactating women after the return of menses

Effectiveness of Fertility Awareness-Based Methods for Pregnancy Prevention During the Postpartum Period

OBJECTIVES

To summarize the evidence on typical and perfect-use effectiveness of fertility awareness-based methods for avoiding pregnancy during the postpartum period, whether breastfeeding or not.

STUDY

Design We conducted a systematic review of studies published in English, Spanish, French, or German by November 2021 in MEDLINE, EMBASE, CINAHL, Web of Science, and ClinicalTrials.gov. Abstract and full text review were completed by two independent reviewers. Study inclusion: at least 50 subjects who enrolled prior to experiencing three cycles after childbirth and were using a specific fertility awareness-based method to avoid pregnancy; unintended pregnancy rate or probability calculated; postpartum amenorrheic and postpartum cycling individuals analyzed separately; and prospectively measured pregnancy intentions and outcomes. Outcomes were abstracted and study quality was systematically assessed by two independent investigators.

RESULTS

Four studies provided effectiveness data for one specific fertility awareness-based method among postpartum individuals. Of these, there were zero high quality, one moderate quality, and three low quality for our question of interest. Typical-use pregnancy probability for the first six cycles postpartum for Marquette Method users was 12.0 per 100 women years (standard error [SE] not reported) and for Billings Ovulation Method users ranged from 9.1 (SE 3.9) for non-lactating women <30 years old to 26.8 (SE 4.6) for lactating women <30 years old. Typical-use pregnancy probabilities for the first six months post-first menses for the Postpartum Bridge to Standard Days Method users was 11.8 (95% confidence interval 6.01-17.16) and for Billings Ovulation Method users was 8.5 per 100 women (SE 1.7).

CONCLUSIONS

The current evidence on the effectiveness of each fertility awareness-based method for postpartum persons is very limited and of mostly low quality. More high quality studies on the effectiveness of fertility awareness-based method in postpartum persons are needed to inform clinical counseling and patient-centered decision-making.

Dissociation between Cervical Mucus and Urinary Hormones during the Postpartum Return of Fertility in Breastfeeding Women

Identifying the return of fertility with cervical mucus observations is challenging during the postpartum period. Use of urinary measurements of estrogen and progesterone can assist in understanding the return to fertility during this period. The purposes of this study were to describe the postpartum return of fertility by an analysis of total estrogen (TE) and pregnanediol glucuronide (PDG) profiles and to correlate these profiles with cervical mucus observations. Twenty-six participants collected urine samples during the postpartum period and recorded mucus scores. TE and PDG hormones were analyzed and compared with mucus scores. During amenorrhea, mucus reflected TE changes in only 35 percent of women; after amenorrhea, typical mucus patterns were seen in 33 percent of cycles. We concluded that postpartum mucus and hormone profiles are significantly dissociated but that monitoring urinary hormones may assist in identifying the return of fertility. We also identified different hormonal patterns in the return to fertility. The postpartum period is a challenging time for identifying the return of fertility. The purposes of this study were to describe the hormonal patterns during the return of fertility and to correlate these patterns with cervical mucus observations. Twenty-six postpartum women collected urine samples and recorded mucus scores. Urinary estrogen and progesterone hormones were analyzed and compared with mucus scores. Before the return of menses, mucus reflected hormonal changes in only 35 percent women and after first menses in 33 percent of cycles. We found that hormone profiles do not correlate well with mucus observations during the postpartum return of fertility.

Case Reports of the Marquette Method

The Marquette method (MM) is a flexible system whereby patients can use cervical mucus and temperature observations in conjunction with the ClearBlue Fertility Monitor (CBFM) an algorithm to clarify the beginning, peak, and end of the fertile window. Two cases are presented which illustrate useful aspects of the MM. The first case involves a couple who have not had success with a Diocesan sympto-themal method and find the objective nature of the CBFM to be critical in sustaining their commitment to natural family planning (NFP). The second case examines a couple in the breastfeeding/weaning period using the Marquette Breastfeeding Protocol. It is the author's hope that these case presentations increase the Catholic Physician's desire to learn more about NFP.

Current Medical Research Summer–Fall 2009

Note that the “Current Medical Research” feature focuses on issues relevant to natural family planning and the beginning of life. This piece is complemented by medical reviews published in The National Catholic Bioethics Quarterly, which focus more on other areas of general medical interest including end-of-life issues.—Ed.

Variability in the Phases of the Menstrual Cycle

OBJECTIVE

To determine variability in the phases of the menstrual cycle among healthy, regularly cycling women.

DESIGN

A prospective descriptive study of a new data set with biological markers to estimate parameters of the menstrual cycles.

PARTICIPANTS

One hundred forty one healthy women (mean age 29 years) who monitored 3 to 13 menstrual cycles with an electronic fertility monitor and produced 1,060 usable cycles of data. MEASURES AND OUTCOMES: Variability in the length of the menstrual cycle and of the follicular, fertile, and luteal phases, and menses. The estimated day of ovulation and end of the fertile phase was the peak fertility reading on the monitor (i.e., the urinary luteinizing hormone surge).

RESULTS

Mean total length was 28.9 days (SD = 3.4) with 95% of the cycles between 22 and 36 days. Intracycle variability of greater than 7 days was observed in 42.5% of the women. Ninety-five percent of the cycles had all 6 days of fertile phase between days 4 and 23, but only 25% of participants had all days of the fertile phase between days 10 and 17.

CONCLUSIONS

Among regularly cycling women, there is considerable normal variability in the phases of the menstrual cycle. The follicular phase contributes most to this variability.

Protocol for determining fertility while breastfeeding and not in cycles

A protocol was developed and evaluated for nonovulating breastfeeding women to determine potential fertility with an electronic hormonal fertility monitor. The amount of required abstinence (i.e., days of potential fertility) through the first menstrual cycle indicated by the fertility monitor was significantly lower (17% of the total days) compared with the amount of abstinence (50% of the total days) indicated by the self-observation of cervical mucus.

New low- and high-tech calendar methods of family planning

Calendar-based methods are not usually considered effective or useful methods of family planning among health professionals. However, new "high-" and "low"-tech calendar methods have been developed, which are easy to teach, to use, and may be useful in helping couples avoid pregnancy. The low-tech models are based on a fixed-day calendar system. The high-tech models are based on monitoring urinary metabolites of female reproductive hormones. Both systems have high levels of satisfaction. This article describes these new models of family planning and the research on their effectiveness. The author proposes a new algorithm for determining the fertile phase of the menstrual cycle for either achieving or avoiding pregnancy.