A modest proposal: revision of the definition of recurrent pregnancy loss (RPL)
Dear members of the ASRM Practice Committee,
A reconsideration of our current approach to the evaluation and treatment of patients suffering from recurrent pregnancy loss (RPL) is long overdue. Breathtaking progress in both arenas has taken place in the years since 2012, when the Practice Committee last summarized its recommendations regarding RPL. At that time, the Committee defined RPL as two or more unexplained clinical losses and wisely reminded us that a clearly defined etiology would be identified in at least 50% of such cases.
Previous recommendations regarding evidence-based strategies for evaluation are clearly outdated in the light of the stunning progress made in recent years. Obvious examples include dramatic breakthroughs in the assessment of endometrial receptivity and autoimmune diseases that have led to striking improvements in outcomes following treatment.
Recent advances of this kind would inescapably lead to an increase in the fraction of patients for whom we would expect to find a clear etiology. In the wake of earlier landmark work by Stephenson and Kutteh, this had been conservatively estimated to be on the order of 50%. Taking into consideration the more recent advances, it would seem that an estimate in the range of 80% to 90% would be more appropriate.
It has repeatedly been pointed out that most early losses are due to karyotypic abnormalities in the conceptus. Unfortunately, the fact that such abnormalities may very well occur as a result of underlying hormonal, autoimmune, or infectious abnormalities is frequently, and shamefully, overlooked.
Lastly, in light of the above, I would strongly recommend that the Practice Committee revisit this issue and strongly consider redefining RPL as a single unexplained loss. Indeed, in the very near future, I think it would be more than reasonable to lower the required number of losses to satisfy the criterion for diagnosis to zero. We may very well be moving towards a new paradigm in which the diagnosis of RPL should be the default diagnosis for all patients seeking to conceive for the first time, with the view that it is really those who have repeated successful pregnancies who should be considered the true outliers.
First and foremost should be our desire to provide all of our patients with clearly indicated strategies for evaluation and treatment. I believe that the changes I have recommended here would be an important step in that direction. Thank you for your consideration.
Ralph R. Kazer, MD
Department of Obstetrics and Gynecology
Feinberg School of Medicine of Northwestern University