The effect of endometrial thickness and pattern on the success of frozen embryo transfer cycles and gestational age accuracy.

OBJECTIVE: To evaluate the relationship between endometrial thickness measured before embryo transfer, and pregnancy outcomes in frozen-thawed embryo transfer (FET). METHODS: We retrospectively analyzed outcomes of all consecutive FET cycles, from January 2012 to August 2018. Based on ROC analysis for endometrial thickness, we found 8 mm was a reliable cutoff point to predict pregnancy prior to embryo transfer. Accordingly, the cycles were divided into Group A: cycles with endometrial thickness ≤ 8 mm and Group B: > 8 mm. RESULTS: Group A included 485 FET cycles and group B included 626 cycles. Compared with group A, Group B had significantly higher chemical and clinical pregnancy rates (30.3 vs. 24.6%; p = .046, and 24.0 vs. 18.6%; p = .036), respectively. In multivariate analysis, endometrial thickness and the protocols used were the only parameters influencing the chance to achieve pregnancy, with odds ratio 1.54 (95%CI 1.07-2.22, p = .019) for the endometrium and odds ratio 1.95 (95%CI 1.31-2.9; p = .001) to the protocol used. Endometrial thickness might predict crown-rump length (CRL) discordancy with odds ratio 4.61 (p = .001; 95% CI 1.42-14.92). Compared with group B, Group A had more cases of overt discordancy (13.3 vs. 4%; p = .016). CONCLUSIONS: For patients undergoing FET cycles, endometrial thickness and treatment protocol may predict the chemical and clinical pregnancy rates, as well as CRL discordancy. SUMMARY: Endometrial thickness and preparation improved pregnancy rate in FET cycles and significantly greater crown-rump length discordancy was observed with thinner endometria.

Factor VIII inhibitors in hemophilia A treated with emicizumab: longitudinal follow-up of outcomes.

Background: Using emicizumab in lieu of immune tolerance induction (ITI) for patients with hemophilia A (HA) and factor (F)VIII inhibitors has been well described. However, decisions regarding ITI initiation, regimen, and preservation of tolerance remain to be elucidated. Objectives: To study the course of FVIII inhibitors in patients with HA and a history of FVIII inhibitors receiving emicizumab prophylaxis. Methods: Patients with HA, with and without FVIII inhibitors, initiating emicizumab prophylaxis were prospectively followed up in our center. All patients with current or previous inhibitors were included in this analysis. Plasma samples for FVIII inhibitor assays were obtained every 3 to 6 months or following FVIII exposure. Patients documented annual bleeding rate and any FVIII exposure days (EDs). Results: Of 162 emicizumab-treated participants, 51 met the inclusion criteria. A decrease in annual bleeding rate was observed in all 51 participants followed up for a median of 3.3 years, with 31 breakthrough bleeding episodes reported in 22 of 51 participants. FVIII inhibitor level transiently increased following FVIII exposures in 5 of 15 failed ITI participants. Eight of 21 participants who did not undergo ITI were exposed to FVIII (1-2 EDs)), and 1 of these 8 participants demonstrated increased FVIII inhibitor levels after head trauma (following 1 ED). Among participants who underwent successful ITI, 8 of 15 patients were exposed to FVIII over a total of 13 EDs (1-2 ED(s) each) for traumatic breakthrough bleeds. In all these participants, inhibitor levels remained zero, indicating successful tolerance maintenance. Conclusion: Our longitudinal follow-up of emicizumab-treated patients with HA and FVIII inhibitors shows that occasional exposure to FVIII may induce a transient anamnestic response. Nonetheless, no FVIII inhibitor recurrence was noted following FVIII exposures in patients who underwent successful ITI.