The study, led by Emily A. Clarke of the Icahn School of Medicine at Mount Sinai and Reproductive Medicine Associates of New York, together with colleagues including Alan B. Copperman, examined 203 patients who experienced early pregnancy loss and subsequently underwent a single euploid embryo transfer, a procedure in which a genetically screened embryo with the correct number of chromosomes is transferred one at a time. Of these patients, 88 were managed medically, typically with misoprostol, while 115 underwent surgical management, usually dilation and curettage. Because all participants received embryos confirmed to be chromosomally normal through preimplantation genetic testing, the researchers were able to isolate the contribution of the uterine environment itself, removing the confounding noise of embryo aneuploidy, which is the leading cause of early miscarriage and failed implantation.

The primary outcome was the change in endometrial thickness between the cycle in which the pregnancy was lost and the subsequent frozen embryo transfer cycle. Endometrial thickness, measured by transvaginal ultrasound, is one of the most closely watched parameters in reproductive medicine because a lining thinner than seven millimeters is associated with markedly reduced implantation and live birth rates. Large analyses of tens of thousands of embryo transfers, including a 2022 study of more than 96,000 autologous transfers published in Fertility and Sterility, have demonstrated a graded relationship between lining thickness and success, making any iatrogenic thinning of the endometrium a legitimate clinical concern.

What the researchers found was striking in its neutrality. Between the initial and subsequent transfer cycles, endometrial thickness changed by an average of plus 0.3 millimeters in the medically managed group and plus 0.1 millimeters in the surgically managed group, a difference that was statistically indistinguishable with a P value of 0.65. In the subsequent transfer cycle itself, the average lining measured 9.4 millimeters in the medical group and 9.1 millimeters in the surgical group, again with no significant difference. Cycle cancellation because of a persistently thin lining, defined as less than seven millimeters, was rare in both arms, occurring in 3.4 percent of medically managed patients and 2.6 percent of surgically managed patients. In practical terms, the surgical instrumentation that many feared might scar the uterine cavity did not measurably impair the endometrium’s ability to proliferate under hormonal preparation.

This finding carries particular weight because prior literature had raised genuine alarms. Earlier studies, including work by Shufaro and colleagues in 2008 and investigations by Davar and Azumaguchi, described a thin, unresponsive endometrium as a possible complication of surgical curettage, with some patients developing linings that failed to thicken even with high doses of estrogen. Asherman’s syndrome, the formation of intrauterine adhesions after aggressive curettage, remains a recognized and sometimes devastating consequence of uterine instrumentation. The new data do not erase those risks, which are uncommon but real, yet they suggest that in the specific population of IVF patients destined for euploid embryo transfer, routine dilation and curettage for early pregnancy loss does not produce a detectable average penalty on endometrial development.

The secondary outcomes told a more nuanced story. While live birth rates in the subsequent transfer cycle were statistically similar between the two groups, 48.8 percent among medically managed patients versus 40.7 percent among surgically managed patients, the rate of clinical pregnancy loss after a positive pregnancy test was significantly higher in the surgical cohort, at 15.7 percent compared with 4.9 percent. After adjusting for potential confounders, surgical management carried an adjusted odds ratio of 3.72 for subsequent pregnancy loss, with a 95 percent confidence interval of 1.11 to 12.47. The authors stopped short of claiming causation, and the absolute difference, roughly eleven percentage points, is modest, but the signal is biologically plausible. Instrumentation of the uterine cavity could theoretically alter the endometrium’s receptivity at a level finer than thickness alone can capture, affecting the molecular dialogue between embryo and lining that governs implantation and placentation.

Endometrial receptivity is a complex process involving the synchronized expression of hundreds of genes, the maturation of the epithelial pinopodes, the recruitment of immune cells, and the development of an adequate blood supply. Research into implantation failure has implicated inflammatory markers and disruptions of this delicate immunological environment. A curettage procedure induces a controlled injury and an inflammatory repair response, and while the lining may regenerate to a normal thickness, subtle alterations in its functional quality could persist. The elevated miscarriage rate observed in the surgical group, despite equivalent lining measurements and equivalent live birth rates among those pregnancies that did progress, hints at exactly this kind of subclinical functional difference, one that ultrasound cannot see but that may manifest as an early pregnancy that implants and then fails.

The study’s design deserves scrutiny. As a single-center retrospective cohort, it cannot randomize patients to treatment arms, and the choice between medical and surgical management was made by patients and physicians based on clinical circumstances, introducing the possibility of selection bias. Patients with heavier bleeding, retained tissue, or hemodynamic instability are more likely to undergo surgery, and these same factors might independently affect subsequent reproductive outcomes. The sample size of 203, while respectable for a single-center study, limits statistical power for rare outcomes, and the wide confidence interval around the miscarriage odds ratio reflects that uncertainty. Nevertheless, the use of euploid single embryo transfers represents a methodological strength that few prior studies on this question have enjoyed, because it controls for the single largest determinant of IVF success, namely embryo chromosomal competence.

For clinicians, the findings translate into a more evidence-based framework for counseling. Patients with early pregnancy loss who have frozen euploid embryos waiting can be told that neither medical nor surgical management appears to compromise their endometrial thickness or their overall chances of a live birth in the next transfer cycle. Those who prefer the certainty and speed of a surgical procedure, or who require it for clinical reasons, can be reassured that the lining typically recovers fully. At the same time, the elevated loss rate in the surgical group gives clinicians a legitimate data point to discuss, particularly for patients with a history of recurrent pregnancy loss who may be especially sensitive to any factor that raises miscarriage risk. The decision should remain individualized, weighing the efficacy, side effects, and completion rates of misoprostol against the operating room requirements of curettage.

The research, presented orally at the American Society for Reproductive Medicine’s scientific congress in Denver in October 2024 before its peer-reviewed publication, adds to a growing body of work aimed at demystifying what happens to the uterus after miscarriage and how best to prepare it for the next attempt. Early pregnancy loss affects roughly one in ten recognized pregnancies, and among IVF patients the emotional and financial stakes of each subsequent cycle are exceptionally high. By demonstrating that endometrial recovery is robust across both management pathways, and by flagging a modest but significant difference in subsequent pregnancy loss, the study gives patients and physicians something they have long lacked: quantitative, embryo-quality-controlled evidence on which to base one of the most common and consequential decisions in reproductive medicine. The authors note that de-identified data are available upon reasonable request, and they emphasize that these findings may help guide counseling for patients navigating the difficult intersection of miscarriage management and fertility treatment.

Subject of Research: How medical versus surgical management of early pregnancy loss affects endometrial thickness and outcomes of subsequent euploid embryo transfers in IVF patients

Article Title: Management of Early Pregnancy Loss: Reproductive Outcome in Subsequent Euploid Embryo Transfers

Article References: Management of Early Pregnancy Loss: Reproductive Outcome in Subsequent Euploid Embryo Transfers. (n.d.). https://doi.org/10.1007/s43032-026-02200-w

Image Credits: AI Generated

DOI: 10.1007/s43032-026-02200-w

Keywords: early pregnancy loss, dilation and curettage, misoprostol, endometrial thickness, euploid embryo transfer, in vitro fertilization, live birth rate, clinical pregnancy loss, reproductive medicine, miscarriage management, Management, Early