Billings natural family planning in Shanghai, China

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.

Effectiveness of Fertility Awareness-Based Methods for Pregnancy Prevention: A Systematic Review

OBJECTIVE

To summarize best available prospective data on typical and perfect use effectiveness of fertility awareness-based methods for avoiding pregnancy.

DATA SOURCES

We conducted a systematic review of studies published in English, Spanish, French, or German by June 2017 in MEDLINE, EMBASE, CINAHL, Web of Science, and ClinicalTrials.gov.

METHODS OF STUDY SELECTION

We reviewed 8,755 unique citations and included 53 studies that contained 50 or greater women using a specific fertility awareness-based method to avoid pregnancy, calculated life table pregnancy probabilities or Pearl rates, and prospectively measured pregnancy intentions and outcomes. We systematically evaluated study quality.

TABULATION, INTEGRATION, AND RESULTS

Of 53 included studies, we ranked 0 high quality, 21 moderate quality, and 32 low quality for our question of interest. Among moderate-quality studies, first-year typical use pregnancy rates or probabilities per 100 woman-years varied widely: 11.2-14.1 for the Standard Days Method, 13.7 for the TwoDay Method, 10.5-33.6 for the Billings Ovulation Method, 4-18.5 for the Marquette Mucus-only Method, 9.0-9.8 for basal body temperature methods, 13.2 for single-check symptothermal methods, 11.2-33.0 for Thyma double-check symptothermal methods, 1.8 for Sensiplan, 25.6 for Persona, 2-6.8 for the Marquette Monitor-only Method, and 6-7 for the Marquette Monitor and Mucus Method. First-year perfect use pregnancy rates or probabilities among moderate-quality studies were 4.8 for the Standard Days Method, 3.5 for the TwoDay Method, 1.1-3.4 for the Billings Ovulation Method, 2.7 for the Marquette Mucus Method, 0.4 for Sensiplan, 12.1 for Persona, and 0 for the Marquette Monitor.

CONCLUSION

Studies on the effectiveness of each fertility awareness-based method are few and of low to moderate quality. Pregnancy rates or probabilities varied widely across different fertility awareness-based methods (and in some cases, within method types), even after excluding low-quality studies. Variability across populations studied precludes comparisons across methods.

Identification and prediction of the fertile window with a new web-based medical device using a vaginal biosensor for measuring the circadian and circamensual core body temperature

Fertility awareness-based (FAB) methods represent a term that includes all family planning methods that are based on the identification of the fertile window. They are based on the woman's observation of physiological signs of the fertile and infertile phases of the menstrual cycle. The first approach consists basically in symptothermal methods accompanied by cervical mucus measurements and clinical menstrual cycling data recording. The second most often used methods are the urinary measurement of E3G and luteinizing hormone (LH) with a personalized computer system. Hence these systems lack the efficacy of the continuous circadian and circamensual measurement of the core body temperature. Only this approach enables the accurate detection of the ovulation during the fertile window. A new medical device called OvulaRing has been developed to fill this gap. In the present study, the system and its first clinical results are presented. OvulaRing is a medical device used just like a tampon. The device is a vaginal ring of evatane that contains an integrated biosensor. This sensor measures continuously every 5 min the core body temperature throughout the entire cycle. This device allows a circadian and circamensual intravaginal exact measurement. With this system, 288 measurements are created per day. The system can detect retrospectively and predict prospectively the fertile window of the users. One hundred and fifty eight women aged between 18 and 45 years used this medical device in an open non-randomized clinical study for 15 months. A total of 470 cycles could be recorded and were able for analysis. By the same time in a subgroup of patients, hormonal assessments of LH, follicle-stimulating hormone, estradiol and progesterone as well as vaginal ultrasound were performed in parallel between the 9th and the 36th day of the cycle. The validation error due to software errors was 0.89% for the retrospective analysis; that means that the accuracy for the detection of the ovulation was 99.11%. Accuracy of 88.8% for a window of 3 days before ovulation, the day of ovulation and the 3 days after ovulation was achieved for the prospective analysis. In the subgroup of woman with recorded pregnancies, it could be shown that after 3.79 months of use (median) pregnancies were observed. In 67.72% in up to 3 months, in 16.36% between 3 and 6 months of use, in 7.27% between 7 and 9 months, in 5.45% between 10 and 12 months and in 1.82% between 13 and 15 months of use of the system. With this new web-based system, a precise determination of the fertile window even in women with ultralong cycles (>35 days) could be detected independently of their personal live circumstances. Exact determination of the fertile window is herewith possible so that OvulaRing represents an evolution in the FAB method for the cycle diagnosis of women with regular, irregular or anovulatory menstrual cycles.

Couple Beads: An integrated method of natural family planning

Various fertility indicators are used by natural family planning methods to identify the fertile and infertile phases of a woman's menstrual cycle: mucus observations, cycle-day probabilities, basal body temperature readings, and hormonal measures of LH and estrogen. Simplified NFP methods generally make use of a single fertility indicator such as cycle-day probabilities (Standard Days Method) or mucus observations (Billings Ovulation Method). The Couple Bead Method integrates the two simplest fertility indicators, cycle-day probabilities and mucus observations, expanding its applicability to all women, regardless of cycle regularity and length. In determining cycle-day probabilities, the Couple Bead Method relies on a new data set from ultrasound-derived determinants of gestational age that more directly define the day of conception and the fertile window. By using a visual-based system of inexpensive colored beads, the Couple Bead Method can be used by couples of all educational and income levels. Lay Summary: Natural family planning methods provide education in regard to the signs of a woman's body which indicate if she is possibly fertile or not. Two important signs are the day of her menstrual cycle and her observations of bleeding and cervical mucus or dryness. The Couple Bead Method teaches a couple how to observe these signs and chart them with a system of colored beads. The Couple Bead Method can be used by women with regular or irregular cycles. The bead sets are inexpensive and consist of a length of plastic cord, colored "pony beads" and safety pins.

The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple's sexual behaviour during the fertile time: a prospective longitudinal study

BACKGROUND

The efficacy of fertility awareness based (FAB) methods of family planning is critically reviewed. The objective was to investigate the efficacy and the acceptability of the symptothermal method (STM), an FAB method that uses two indicators of fertility, temperature and cervical secretions observation. This paper will recommend a more suitable approach to measure the efficacy.

METHODS

Since 1985, an ongoing prospective observational longitudinal cohort study has been conducted in Germany. Women are asked to submit their menstrual cycle charts that record daily basal body temperature, cervical secretion observations and sexual behaviour. A cohort of 900 women contributed 17,638 cycles that met the inclusion criteria for the effectiveness study. The overall rates of unintended pregnancies and dropout rates have been estimated with survival curves according to the Kaplan-Meier method. In order to estimate the true method effectiveness, the pregnancy rates have been calculated in relation to sexual behaviour using the 'perfect/imperfect-use' model of Trussell and Grummer-Strawn.

RESULTS

After 13 cycles, 1.8 per 100 women of the cohort experienced an unintended pregnancy; 9.2 per 100 women dropped out because of dissatisfaction with the method; the pregnancy rate was 0.6 per 100 women and per 13 cycles when there was no unprotected intercourse in the fertile time.

CONCLUSIONS

The STM is a highly effective family planning method, provided the appropriate guidelines are consistently adhered to.

Using cervical mucus and other easily observed biomarkers to identify ovulation in prospective pregnancy trials

To help fulfil the objectives of prospective studies of pregnancy and human development, such as the National Children's Study, there is a need to pinpoint ovulation and conception in a cohort of women. This paper discusses the suitability of using natural and easily observed markers of ovulation for detection of the most likely day of ovulation and conception. Of the biomarkers supported by clinical data, the use of cervical mucus is emphasised as it appears most promising. A considerable amount of data suggests that observation of changes in vaginal discharge from cervical mucus can closely approximate the day of ovulation, is easy to learn and suitable for a large group of women. While this approach could also be cost-effective, a significant drawback may be the learning phase which may take 2-3 instructional sessions for women to fully identify recurring changes across the menstrual cycle.

Characteristics of women associated with continuing instruction in the Creighton Model Fertility Care System

Effective use of natural family planning is strongly dependent upon adequate instruction. The Creighton Model Fertility Care System (CrMS) has a standardized protocol for instruction of new users that includes individual follow-up visits in the first year of use. This study evaluated the number of follow-up visits completed by new CrMS users from eight CrMS centers in the United States. Four follow-up visits were completed by 75.7% of women. Women who continued instruction were more likely to be educated, Catholic, and white, and to have a more challenging reproductive status (discontinuing oral contraceptives, or breastfeeding). These results suggest that the number of follow-up visits needed varies among new CrMS users. Future research should address the optimal length of instruction for adequate use of the CrMS by women with different characteristics and needs.