Raviele, K. M. (2014). Levonorgestrel in cases of rape: How does it work? The Linacre Quarterly, 81(2), 117-129. https://doi.org/10.1179/2050854914Y.0000000017
Raviele KM. Levonorgestrel in cases of rape: How does it work? Linacre Q. 2014;81(2):117-129. doi:10.1179/2050854914Y.0000000017
Raviele, Kathleen Mary. "Levonorgestrel in cases of rape: How does it work?" The Linacre Quarterly, vol. 81, no. 2, 2014, pp. 117-129.
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Dekalb Medical Tucker, Georgia, USA
RRM Academy Synopsis
Review argues fertile-window Plan B likely acts after fertilization
A doctor's review argues the morning-after pill Plan B does not reliably stop ovulation when taken in the fertile window. She concludes the pill likely works after fertilization much of the time. The review examines studies that timed the pill against ovulation. She wrote it to guide Catholic hospitals that treat women after rape.
Study at a glance, narrative review: Review argues fertile-window Plan B likely acts after fertilization. Source: Raviele KM, 2014, PMID 24899748.
Key Findings
In 45 sterilized women, ovulation was suppressed in 80 percent of those dosed at least four days before the LH surge. Those dosed within 3 days of the surge all ovulated.
Women who ovulated after dosing within 3 days of the LH surge starting had deficient progesterone production and a shorter luteal phase, which the author says would interfere with implantation.
In a study of 337 women, 62 of 87 given the pill before ovulation ovulated (71 percent). No pregnancies occurred in those 87 women, though the study expected 13.
Sperm studies found the pill unlikely to affect sperm function: lab sperm changed only at high concentrations, and sperm from the uterus after the pill showed no change in the acrosome reaction.
With meloxicam, an anti-inflammatory drug, taken around the LH surge, 90.9 percent of women had no ovulation or dysfunctional ovulation. The author proposes this drug class as a possible alternative.
Interpretation
This is a narrative review of published studies on how Plan B works. The author wrote it to guide Catholic hospital policy on giving the pill after rape. She bases her after-fertilization view on findings like the pregnancies the Noé study expected but did not see. The author notes that many facts about implantation are still unknown. The findings support more study of meloxicam and other drugs as options to Plan B during the fertile window.
RRM Context
Restorative reproductive medicine pays close attention to cycle timing, since timing changes how a drug acts. This paper's point rests on a six-day fertile window. Methods like NaProTechnology track that window through daily charting.
Our editorial summary of this paper, not the article's abstract.
Abstract
The Ethical and Religious Directives for Catholic Health Care Services allows the use of an emergency contraceptive for a woman who has been raped, as a defense against her attacker's sperm, provided the drug prevents fertilization and does not act against a conceived human life. Catholic emergency rooms around the country have been pressured to provide Plan B (LNG-EC) to patients seeking help after a sexual assault. Catholic bioethicists have supported the use of this drug based on their interpretation of the scientific literature regarding its mechanism of action. This paper presents a review of the mechanisms of action of LNG-EC when given during the fertile window, showing a high probability that it acts against human life rather than preventing fertilization, and proposes another class of drugs as a possible alternative.
