The effect of fresh IVF cycle characteristics on frozen embryo transfer (FET) outcomes

Abstract

Objective: To determine the effect of fresh IVF/ICSI cycles on FET cycle embryo and pregnancy outcomes.Methods: This retrospective cohort study included data from the medical records of 104 FET cycles performed from January 2014 to December 2016. Embryos were previously vitrified and then thawed for embryo transfer. Statistical significance was established at p<0.05. The main endpoints were FET cycle survival and pregnancy rates.Results: A total of 104 FET cycles were analyzed for survival; 94 showed good progression and 84 achieved embryo transfers. Patients with secondary infertility achieved significantly higher pregnancy rates -6/38 (15.8%) vs. 18/46 (39.1%) (p<0.018). Stimulation with FSH/LH resulted in more significant embryo progression, 38/48 (79.2%) vs. 28/46 (60.9%) in the FSH group (p=0.01). Patients who got pregnant from fresh cycles had the highest pregnancy rates in FET cycles (p<0.0001). Lower numbers of frozen embryos correlated with higher pregnancy rates (p=0.048). Embryos frozen on day 2 or 3 had the most significant progression (p<0.0001). Freeze-thaw intervals >12 months yielded higher pregnancy rates, 13/30 (43%), vs. 11/54 (20.4%) (p=0.025). Conclusion:Patient pregnancy in fresh cycles is a good prognostic factor for FET cycle success. Delaying FET by more than 12 months might result in higher pregnancy rates.

Pregnancy outcomes following in vitro fertilization using fresh or frozen embryo transfer

“…Our results regarding the effect of previous fresh cycles on FET cycles are in agreement with the findings reported by Ashrafi et al (2011) and Bushaqer et al (2020), but in contrast with the reports from Doherty et al (2014) and Bdolah et al (2015). Our results showed that the clinical pregnancy rate in cases of FET with a history of successful early pregnancy was significantly higher than cases with the failed pregnancy history (61.30% vs. 43.53%), which means that the previous fresh cycle protocol may affect the pregnancy outcomes arisen from subsequent FET cycles.…”

“…Our results showed that the clinical pregnancy rate in cases of FET with a history of successful early pregnancy was significantly higher than cases with the failed pregnancy history (61.30% vs. 43.53%), which means that the previous fresh cycle protocol may affect the pregnancy outcomes arisen from subsequent FET cycles. However, the previous fresh cycle outcomes did not affect the live birth rate, which confirms the results reported by El-Toukhy et al (2003) and Bushaqer et al (2020). Their results showed that embryo survival arisen from frozen cycle is not affected by the fresh cycles (Bushaqer et al 2020;El-Toukhy et al, 2003).…”

“…However, the previous fresh cycle outcomes did not affect the live birth rate, which confirms the results reported by El-Toukhy et al (2003) and Bushaqer et al (2020). Their results showed that embryo survival arisen from frozen cycle is not affected by the fresh cycles (Bushaqer et al 2020;El-Toukhy et al, 2003). In this regard, some researchers theorized that the good quality embryos in fresh and frozen cycles might lead to pregnancy in both cycles.…”

Comparison of Stimulated Cycles with Low Dose r-FSH versus Hormone Replacement Cycles for Endometrial Preparation Prior to Frozen-Thawed Embryo Transfer in Young Women with Polycystic Ovarian Syndrome: A Single-Center Retrospective Cohort Study from China

“… 8 As known, PCOS patients refer to high responder group, hence, elective freeze-all strategy is recommended worldwide to prevent OHSS, and to alleviate the harmful effects of supra-physiologic steroid hormones on the endometrium before embryo implantation. 9 Chen et al reported that FET increases live birth rates (LBRs) in their RCT of women with PCOS. 10 …”

Comparison of stimulated cycles with low dose r-FSH versus hormone replacement cycles for endometrial preparation prior to frozen-thawed embryo transfer in young women with polycystic ovarian syndrome: A propensity scores matching analysis from 1434 patients

“…IVF had become an important therapeutic technique for infertility of PCOS 8 . As known, PCOS patients refer to high responder group, hence, elective freeze-all strategy is recommended worldwide to prevent OHSS, and to alleviate the harmful effects of supra-physiologic steroid hormones on the endometrium before embryo implantation 9 . Chen et al reported that FET increases live birth rates (LBRs) in their RCT of women with PCOS 10 .…”