Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Apr 16:12:664072.
doi: 10.3389/fendo.2021.664072. eCollection 2021.

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

Junwei Zhang  1 , Zhen Li  1 , Lijun Sun  1 , Yichun Guan  1 , Mingze Du  1
Affiliations

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

Junwei Zhang et al. Front Endocrinol (Lausanne). .

Abstract

Background: The 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.

Methods: It 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).

Results: In 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).

Conclusion: For 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.

Keywords: frozen embryo transfer; letrozole; live birth rate; miscarriage; neonatal outcomes.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

    1. Pereira N, Rosenwaks Z. A fresh(er) perspective on frozen embryo transfers. Fertil Steril (2016) 106:257–8. 10.1016/j.fertnstert.2016.06.028 - DOI - PubMed
    1. Gliozheni O, Calhaz-Jorge C, De Geyter C, Kupka MS, de Mouzon J, Erb K, et al. Assisted reproductive technology in Europe, 2013: results generated from European registers by ESHRE. Hum Reproduct (2017) 32:1957–73. 10.1093/humrep/dex264 - DOI - PubMed
    1. Rienzi L, Gracia C, Maggiulli R, LaBarbera AR, Kaser DJ, Ubaldi FM, et al. Oocyte, embryo and blastocyst cryopreservation in ART: systematic review and meta-analysis comparing slow-freezing versus vitrification to produce evidence for the development of global guidance. Hum Reprod Update (2017) 23:139–55. 10.1093/humupd/dmw038 - DOI - PMC - PubMed
    1. Groenewoud ER, Cohlen BJ, Macklon NS. Programming the endometrium for deferred transfer of cryopreserved embryos: hormone replacement versus modified natural cycles. Fertil Steril (2018) 109:768–74. 10.1016/j.fertnstert.2018.02.135 - DOI - PubMed
    1. De Geyter C, Calhaz-Jorge C, Kupka MS, Wyns C, Mocanu E, Motrenko T, et al. ART in Europe, 2014: results generated from European registries by ESHRE: The European IVF-monitoring Consortium (EIM) for the European Society of Human Reproduction and Embryology (ESHRE). Hum Reproduct (2018) 33:1586–601. 10.1093/humrep/dey242 - DOI - PubMed

LinkOut - more resources