Efficacy of cervical mucus observations plus electronic hormonal fertility  monitoring as a method of natural family planning

Richard J Fehring; Mary Schneider; Kathleen Raviele; Mary Lee Barron

doi:10.1111/j.1552-6909.2007.000129.x

Fertility Awareness Effectiveness

Efficacy of cervical mucus observations plus electronic hormonal fertility monitoring as a method of natural family planning

Fehring RJ, Schneider M, Raviele K, Barron ML

Published March 21, 2007 Journal of Obstetric, Gynecologic, and Neonatal Nursing : JOGNN, 36(2), 152-160

DOI 10.1111/j.1552-6909.2007.000129.x PMID 17371516

RRM Academy Synopsis

Hormonal monitor plus mucus was 97.9% effective with correct use

In a 12-month prospective clinical efficacy trial of 195 women, about 2 out of 100 had an unintended pregnancy with correct use of a hormonal fertility monitor plus cervical mucus observations. With imperfect use, about 14 out of 100 did.

Key Findings

Across 5 clinical sites in 4 cities, 195 women accumulated 1,795 documented months of use and 26 unintended pregnancies, 3 of which occurred with correct use.
Under correct use, the unintended pregnancy rate was 2.1% over 12 months, equal to 97.9% effectiveness (95% CI = 0.96-1.00).
When all unintended pregnancies and all months of use were counted, the 12-month rate was 14.2%, equal to 85.8% effectiveness.
Of the 195 participants, 102 (52.3%) completed the full study period. Nineteen (9.7%) left in order to conceive, and 12 of them conceived in the first cycle of trying.
Couples avoided intercourse and genital contact from the first high monitor reading or first mucus observation until 3 full days after the last peak reading or last peak day of mucus.

Interpretation

This prospective trial followed women aged 18 to 42, with cycles of 21 to 42 days and no known fertility problems, who learned the method from experienced natural family planning teachers. Correct use means the rules of the method were consistently followed, so the two rates reflect different patterns of use. The authors note that the study had no comparison group. The findings support larger studies of this approach, including in breastfeeding and perimenopausal women.

RRM Context

Fertility awareness-based methods such as the Creighton Model read the ovulatory cycle through cervical mucus. This trial adds urinary markers of the estrogen rise and the LH surge that precede ovulation. Cycle-charting-informed care works with the body's own biomarkers, and the same signs can guide a couple who wish to conceive.

Our editorial summary of this paper, not the article's abstract.

Abstract

Objective

To determine the effectiveness of an electronic hormonal fertility monitor plus cervical mucus monitoring to avoid pregnancy.

Design

A 12-month prospective clinical efficacy trial.

Design, Setting, and Participants

One hundred ninety five (195) women (mean age 29.8 years) seeking to avoid pregnancy with a natural method at 5 clinical sites in 4 cities.

Intervention

Each participant was taught to track fertility by self-observation of cervical mucus and an electronic monitor that measures urinary levels of estrone-3-glucuronide and luteinizing hormone.

Main Outcome Measures

Correct- and typical-use unintended pregnancy rates.

Results

There were a total of 26 unintended pregnancies, 3 with correct use. With 1,795 months of use, the correct-use pregnancy rate was 2.1% per 12 months of use (i.e., 97.9% effective in avoiding pregnancy when rules of the method were always followed) and the imperfect-use pregnancy rate was 14.2% per 12 months of use (i.e., 85.8% effective in avoiding pregnancy when rules of the method were not always followed and all unintended pregnancies and months of use were included in the calculations).

Conclusions

Correct use of an electronic hormonal fertility monitor with cervical mucus observations can be as effective as other fertility awareness-based methods of natural family planning. Comparative studies are needed to confirm this conclusion.

Read the guide

Fertility Awareness Methods Compared

Topics

Fertility Awareness Effectiveness Typical and Perfect Use

Fertility Awareness › Effectiveness › Typical and Perfect Use

Richard J Fehring, Mary Schneider, Kathleen Raviele, Mary Lee Barron

Rick Fehring, Dick Fehring, Rich Fehring, R Fehring, M Schneider, K Raviele, M Barron

PMID 17371516 17371516 DOI 10.1111/j.1552-6909.2007.000129.x 10.1111/j.1552-6909.2007.000129.x Fehring et al. 2007, Fehring 2007

Keywords

Biomarkers