Experience with 50 mcg and 75 mcg dl-norgestrel as a mini-pill in India

Effectiveness and efficacy rates of progestin-only pills: A comprehensive literature review

OBJECTIVES

To synthesize published literature on POP effectiveness and efficacy.

STUDY DESIGN

We searched PubMed Central, PubMed, and the Cochrane library through March 07, 2022. We included articles written in English reporting a Pearl Index or life table rate for pregnancy. We excluded articles only assessing formulations that: were never marketed globally, are only sold in combination with estrogen, are currently sold only for noncontraceptive purposes, or were not given to participants continuously. Four researchers independently extracted data and two analyzed data using Excel and R.

RESULTS

We included 54 studies. Among studies at low or moderate risk of bias, the median Pearl Index rate (the failure rate during typical use) was 1.63 (range 0.00-14.20, IQR 4.03) and the median method failure Pearl Index rate (the failure rate during perfect use) was 0.97 (range 0.40-6.50, IQR 0.68). Excluding the newer formulations, Desogestrel and Drospirenone, which are closer to combined oral contraceptives in that they prevent pregnancy by inhibiting ovulation, the median Pearl Index rate is 2.00 (range 0.00-14.12, IQR 2.5) and the median method failure Pearl Index rate is 1.05 (range 0.00-10.90, IQR 1.38).

CONCLUSIONS

Among studies at low or moderate risk of bias, the median Pearl Index rate during typical POP use was much lower than currently estimated (7.00), while the median perfect use rate was similar to current estimates.

IMPLICATIONS

Future research should investigate the possibility that POPs may be much more effective during typical use than currently believed.

A review of the effectiveness of a progestogen-only pill containing norgestrel 75 µg/day

OBJECTIVES

To review published data on the effectiveness of a progestogen-only pill containing norgestrel 75 µg/day which should be under consideration by the FDA in 2022 for sale over the counter in the US.

STUDY DESIGN

A literature search in MEDLINE, EMBASE, and COCHRANE REVIEWS using specified search terms and adding related cross-references.

RESULTS

We identified a total of thirteen relevant studies of women using norgestrel 75 µg/day. None were reported with the rigor characteristic of trial reporting today. Nevertheless, six studies provided data on 3,184 women who were not breastfeeding, followed for over of 35,000 months and reported a range of overall failure rates during typical use of norgestrel 75 µg/day from 0 to 2.4/hundred woman-years giving an aggregate Pearl Index of 2.2. Seven additional studies involved 5,445 women some of whom were breastfeeding for at least part of the period of follow-up. More than 36,000 months of use yielded 12-month life table cumulative pregnancy rates for norgestrel 75 µg/day ranging from 0 to 3.4. We were unable to calculate an aggregate Pearl Index for the breastfeeding studies because of lack of crucial data.

CONCLUSIONS

The data support that norgestrel 75 µg/day is highly effective in clinical use, with similar estimates of failure in breastfeeding and non-breastfeeding women, providing support to the case for approval without the need to see a healthcare provider.

A multicenter clinical trial of a progestin-only oral contraceptive in lactating women

A non-comparative study of a progestin-only oral contraceptive (POC) containing 75 micrograms norgestrel was conducted at 22 sites in 14 countries. This study was designed to evaluate safety, contraceptive efficacy, and the overall acceptability of a POC in breastfeeding women. A total of 4,088 women entered the study over a three-year period and 29,399 woman-months of experience was gathered. Women had follow-up visits at 2, 6, and 11 months after admission. Headaches and vaginal discharge were the medical complaints most commonly reported by women, both prior to and after admission. Menstrual problems were reported by 59% of the women after admission. Of the 3,714 women who returned for at least one follow-up visit, 1,101 (29.6%) discontinued through month 11. The 11-month total discontinuation percentage, including those lost to follow-up (25.3%) was 51.6%. The most common reason given for discontinuation was a woman's desire for a change in contraceptive method. Only 4.9% discontinued pill use for menstrual problems, a percentage far below those generally reported for POCs. Twenty-nine unintended pregnancies occurred through 11 months giving a gross cumulative life table rate of 1.2 per 100 women (Pearl Index = 1.4). The POC appears to be a safe, effective and acceptable contraceptive option for postpartum breastfeeding women.

Mini-pill in lactating women

A non-comparative study of the progestogen-only oral contraceptive, norgestrel 0.075 mg, in breast-feeding women was conducted at the Centro de Investigaciones Regionales, Merida, Yucatan, Mexico. The study was designed to evaluate the overall acceptability and contraceptive efficacy of norgestrel in breast-feeding women. This report includes a survey of 200 women, all of whom were less than 26 weeks postpartum at admission; 113 were interval patients and 87 were postpartum. Follow-up visits were scheduled at 2, 6 and 12 months after admission. Overall, women experienced an increase in intermenstrual bleeding, amenorrhea, vaginal discharge and breast discomfort. The discontinuation rate at 12 months was 32.5 and the corresponding lost to follow-up rate was 22.5; this is a measure of acceptability. The 12-month life-table rate for pregnancy was 3.4 with a standard error of 2.0. Three women discontinued use of the mini-pill due to accidental pregnancy. One pregnancy was attributed to user failure and the woman conceived 9 months after entering into the study; the other two were attributed to method failure, one woman conceived 3 months after admission and the other conceived 6 months after admission.