Luteinizing Hormone and Progesterone in Women Under Postcoital Contraception with d-Norgestrel

Garmendia, Fausto; Kesseru, E; Urdanivia, Enrique; Valencia, Manuel Silva

doi:10.1016/s0015-0282(16)42191-6

Cited by 14 publications

(3 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The literature available at that time on the mechanism of progestin-only emergency contraception was rather convoluted, especially regarding post-fertilization. Many studies evidenced the ability of post-coital levonorgestrel to delay or suppress ovulation (e.g., Spona et al 1975;Garmendia et al 1976;Landgren et al 1989;Durand et al 2001;Hapangama et al 2001;Marions et al 2002). However, its effect on fertilization was not as well studied or evidenced (limited to Kesserü et al 1974Kesserü et al , 1975, and its effects on implantation were difficult to replicate consistently (for positive findings, see Landgren et al 1989;Moggia et al 1974;Shirley et al 1995;Ugocsai et al 1984; for negative findings, see Durand et al 2001;Marions et al 2002).…”

Section: A Political Instrument For/against Access and Agencymentioning

confidence: 99%

Broadening the scope of our understanding of mechanisms: lessons from the history of the morning-after pill

ChoGlueck

2019

Synthese

View full text Add to dashboard Cite

Philosophers of science and medicine now aspire to provide useful, socially relevant accounts of mechanism. Existing accounts have forged the path by attending to mechanisms in historical context, scientific practice, the special sciences, and policy. Yet, their primary focus has been on more proximate issues related to therapeutic effectiveness. To take the next step toward social relevance, we must investigate the challenges facing researchers, clinicians, and policy makers involving values and social context. Accordingly, we learn valuable lessons about the connections between mechanistic processes and more fundamental reasons for (or against) medical interventions, particularly moral, ethical, religious, and political concerns about health, agency, and power. This paper uses debates over the controversial morning-after pill (emergency contraception) to gain insight into the deeper reasons for the production and use of mechanistic knowledge throughout biomedical research, clinical practice, and governmental regulation. To practice socially relevant philosophy of science, I argue that we need to account for mechanistic knowledge beyond immediate effectiveness, such as how it can also provide moral guidance, aid ethical categorization in the clinic, and function as a political instrument. Such insights have implications for medical epistemology, including the value-laden dimensions of mechanistic reasoning and the "epistemic friction" of values. Furthermore, there are broader impacts for teaching research ethics and understanding the role of science advisors as political advocates.

show abstract

Section: A Political Instrument For/against Access and Agencymentioning

confidence: 99%

Broadening the scope of our understanding of mechanisms: lessons from the history of the morning-after pill

ChoGlueck

2019

Synthese

View full text Add to dashboard Cite

show abstract

“…The same d-norgestrel regimen was associated with a reduced luteinizing hormone surge in two other studies. 51,52 The results of these studies suggest that levonorgestrel (d-norgestrel) can inhibit the luteinizing hormone surge, even at a relatively low dose. The authors of another study observed delayed but otherwise normal ovulatory cycles when women received repeated doses of levonorgestrel 0.75 mg on cycle days 2, 4, 6, and 8.…”

Section: Summary Of Studies With Data On the Effect Of The Yuzpe Rementioning

confidence: 99%

Mechanisms of Action of Hormonal Emergency Contraceptives

2010

View full text Add to dashboard Cite

Hormonal emergency contraceptives have been used to prevent unwanted pregnancy for more than 3 decades. The mechanisms of action of the regimen containing a combination of estrogen and progestin, known as the Yuzpe regimen, and those of the levonorgestrel regimen continue to be controversial, especially over the possibility that these regimens might act by interfering with implantation of the fertilized ovum. We performed a search of the PubMed (1949-July 2009) and EMBASE (1980-July 2009) databases to identify literature on the mechanisms of action of these contraceptive regimens, and data were extracted from pertinent English-language studies. We classified studies according to the approach taken by the investigators to study the actions of emergency contraceptives on pregnancy: an indirect method that uses statistical models to determine whether emergency contraceptives would be as effective as reported if they act only by disrupting ovulation; direct observation of the effects of emergency contraceptives on surrogate outcomes, including ovulation, sperm activity, hormonal levels, and endometrial receptivity to implantation; and analysis of directly observed pregnancy outcomes against statistical data. Acceptability of emergency contraceptives by women and clinicians may depend on personal opinions about when life or pregnancy begins. The evidence strongly supports disruption of ovulation as a mechanism of action. The data suggest that emergency contraceptives are unlikely to act by interfering with implantation, although the possibility has not been completely excluded. The data also suggest that emergency contraceptives are ineffective after ovulation. Women and clinicians who consider implantation or later events to be the beginning of pregnancy should be aware that emergency contraceptives are likely nonabortive by this definition of pregnancy.

show abstract

“…The available information suggests the combination of a disruptive effect on the pituitary-ovarian axis, and direct action at ovarian and endometrial levels [59]. This effect will only be operative if progestogens were used frequently to maintain an effect on cervical mucus.…”

Section: Mechanisms Involving the Uterusmentioning

confidence: 99%