Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes

Glujovsky, Demián; Pesce, Romina; Sueldo, Carlos; Retamar, Andrea Marta Quinteiro; Hart, Roger; Ciapponi, Agustín

doi:10.1002/14651858.cd006359.pub3

Cited by 65 publications

(59 citation statements)

References 75 publications

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“…High-quality evidence shows no consistent advantage of any endometrial preparation has been established (62,63). Moreover, A large meta-analysis study with a total of 31 RCTs (5426 women) in 2020 failed to show a definitive optimal protocol for endometrial preparation (64). However, letrozole is cheap, being patient-friendly, yielding at least equivalent pregnancy rates when compared with natural and artificial cycles with or without suppression, require less luteal support than artificial cycles.…”

Section: Letrozole In Preparation Of Endometrium For Fetmentioning

confidence: 99%

Letrozole for Female Infertility

et al. 2021

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Letrozole, an aromatase inhibitor that blocks estrogen synthesis by inhibiting the final step of the estrogen biosynthetic pathway, has been used in the applications of a wide range of infertility settings. It has been more than 20 years since the initial clinical trial of letrozole for ovulation induction. In light of the accumulating clinical and basic evidence, the efficacy and safety of letrozole have been identified. This mini review focuses on our current knowledge of the applications and mechanisms of letrozole for female infertility and various questions are put forward about how letrozole could be more effectively used.

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Section: Letrozole In Preparation Of Endometrium For Fetmentioning

confidence: 99%

Letrozole for Female Infertility

et al. 2021

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“…There are different FET cycle regimens used to prepare the endometrium, including natural cycles, hormone replacement therapy (HRT) with estrogen and progesterone, cycles in which ovulation is induced by drugs, and gonadotrophin-releasing hormone agonist (GnRH-a) cycles. Although there are many options for the preparation of the endometrium, there is still no uniform recommendation for the preparation of the FET endometrium for different groups of women to date (6)(7)(8). For patients with abnormal ovulation in particular, there have been few studies on FET protocols; notably, most of these studies focus only on the clinical pregnancy rate or LBR (9)(10)(11) and pay little attention to the regimen's safety for offspring.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Pregnancy and Neonatal Outcomes of Single Frozen Blastocyst Transfer Between Letrozole-Induction and HRT Cycles in Patients With Abnormal Ovulation

et al. 2021

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BackgroundThe use of frozen embryo transfer (FET) cycles has dramatically risen. The optimal endometrial preparation method for women undergoing FET is of utmost importance to provide the optimal chances of pregnancy. For patients with abnormal ovulation in particular, there have been few studies on FET protocols; notably, most of these studies focus only on the clinical pregnancy rate or live birth rate (LBR) and pay little attention to the regimen’s safety for offspring.MethodsIt was a retrospective cohort study. First FET cycle with a single blastocyst from whole embryo frozen IVF/ICSI at the Reproductive Center of Third Affiliated Hospital of Zhengzhou University between January 2016 and January 2020. The LBR was the primary outcome of interest. The secondary outcome measures were miscarriage rate and offspring safety, including preterm birth, low birthweight (LBW), small-for-gestational age (SGA), macrosomia and large-for-gestational age (LGA).ResultsIn total, 2782 FET cycles met the eligibility criteria for analysis. Additionally, there were 1178 singleton births from FET cycles. The clinical pregnancy rate was 58.4% in the L-FET group and 54.5% in the HRT group, with no statistical significance (P=.116). The miscarriage rate was higher in the HRT group than in the L-FET group (21.7% vs. 14.3%, P=.005). The LBR was significantly higher in the L-FET group than in the HRT group (49.6% vs. 41.7%, P=.001). Neonatal outcomes were similar between the two groups. After adjustments for confounding factors, the LBR was higher in the L-FET group (aOR 1.30, 95% CI 1.06-1.58). The rate of miscarriage was lower in the L-FET group (aOR 0.63, 95% CI 0.44-0.90).ConclusionFor patients with abnormal ovulation, the L-FET regimen has a higher LBR and lower miscarriage rate than HRT. The neonatal outcomes were similar between the two groups.

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“…In terms of estrogens, natural as well as synthetic E 2 can be used, but again to our knowledge, no trial compared these two forms of E 2 usage in HRT cycles. Different routes, including oral (micronized estradiol or estradiol valerate), vaginal (estradiol valerate) or transdermal (estradiol gel), can be used for the administration of E 2 with comparable reproductive outcomes (5). Although vaginal E 2 may be administered in a ring, tablet or cream forms, local vaginal irritation, discomfort, and unsatisfactory absorption especially when administered together with vaginal P are the reasons why the vaginal route of E 2 administration is not the preferred route by the majority of IVF clinics (10).…”

Section: Hormone Replacement Treatment (Hrt) Estrogen Administrationmentioning

confidence: 99%

“…Despite the increase in FET, the most optimal priming protocol of the endometrium is still a matter of debate (5). The available FET protocols are i) true natural cycle (t-NC) with/ without luteal phase support (LPS) ii) modified NC (modified-NC) with/without LPS, iii) hormone replacement treatment (HRT) with or without gonadotropin releasing hormone (GnRH) analogue suppression, and iv) mild ovarian stimulation (mild-OS) using gonadotropins, clomiphene citrate (CC), or letrozole (Table 1).…”

Section: Introductionmentioning

confidence: 99%

Preparation of the Endometrium for Frozen Embryo Transfer: A Systematic Review

et al. 2021

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Despite the worldwide increase in frozen embryo transfer, the search for the best protocol to prime endometrium continues. Well-designed trials comparing various frozen embryo transfer protocols in terms of live birth rates, maternal, obstetric and neonatal outcome are urgently required. Currently, low-quality evidence indicates that, natural cycle, either true natural cycle or modified natural cycle, is superior to hormone replacement treatment protocol. Regarding warmed blastocyst transfer and frozen embryo transfer timing, the evidence suggests the 6th day of progesterone start, LH surge+6 day and hCG+7 day in hormone replacement treatment, true natural cycle and modified natural cycle protocols, respectively. Time corrections, due to inter-personal differences in the window of implantation or day of vitrification (day 5 or 6), should be explored further. Recently available evidence clearly indicates that, in hormone replacement treatment and natural cycles, there might be marked inter-personal variation in serum progesterone levels with an impact on reproductive outcomes, despite the use of the same dose and route of progesterone administration. The place of progesterone rescue protocols in patients with low serum progesterone levels one day prior to warmed blastocyst transfer in hormone replacement treatment and natural cycles is likely to be intensively explored in near future.

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Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes

Abstract: Editorial group: Cochrane Gynaecology and Fertility Group. Publication status and date: New search for studies and content updated (conclusions changed), published in Issue 10, 2020.

Cited by 65 publications

References 75 publications

Letrozole for Female Infertility

Letrozole for Female Infertility

Comparison of Pregnancy and Neonatal Outcomes of Single Frozen Blastocyst Transfer Between Letrozole-Induction and HRT Cycles in Patients With Abnormal Ovulation

Preparation of the Endometrium for Frozen Embryo Transfer: A Systematic Review

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