Am Fam Physician. 2019;100(7):392-393
Original Article: First Trimester Bleeding: Evaluation and Management
Issue Date: February 1, 2019
Available online at: https://www.aafp.org/afp/2019/0201/p166.html
To the Editor: The authors of this article provided a comprehensive and valuable overview of caring for patients with first trimester bleeding. However, we disagree with their conclusions on the role of progestins in the management of threatened abortion and the prevention of early pregnancy loss.
They state that “bed rest or progestins should not be recommended to prevent early pregnancy loss in patients with first trimester bleeding because these interventions have not been proven effective.” However, evidence of no benefit (bed rest1) is a different problem than no evidence of benefit (progestins, until recently). The Cochrane review cited in the article was updated in August 2018 and reported that the use of a progestogen probably reduces the rate of spontaneous miscarriage, which was supported by moderate-quality evidence.2
The authors also state that “there is insufficient evidence to support the use of progestin for the prevention of early pregnancy loss,” citing the Cochrane review and a practice bulletin from the American College of Obstetricians and Gynecologists, which cites the same Cochrane review. However, a separate Cochrane review concluded that for women with unexplained recurrent miscarriages, progestogen therapy probably reduces the rate of miscarriage in subsequent pregnancies.3 A draft guideline of the United Kingdom's National Institute for Health and Care Excellence suggests that progestin therapy be considered, but that patients be counseled that the evidence of benefit is not strong.4
There is a need for high-quality studies to determine the optimal dosage and route of administration in a population representative of patients we treat. In the meantime, offering progestin therapy to patients in this difficult situation is an option that is not likely to be harmful and may very well be helpful.
The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the U.S. government, the Department of Defense, or the U.S. Air Force at large.
In Reply: We thank Drs. Bryce and Sisk for highlighting this new evidence, which was published after the final submission of our article. We agree with the conclusions they share from the updated Cochrane reviews regarding the potential benefits of progestin therapy in threatened miscarriage and the prevention of recurrent miscarriage.1,2 We appreciate their mention of proposed guideline updates and expect that other national organizations may issue updates as well. We also strongly support their suggestion that more high-quality research is needed regarding optimal dosing and route of administration of progestins and to clarify the magnitude of the benefits vs. harms.
