The optimal endometrial preparation protocol in FET cycles of women with endometriosis.

None of the commonly used endometrial preparation protocols is superior to the others.

Key Points

Importance:

• The information concerning the effect of long-term GnRHa treatment on the live birth rate or perinatal complication rate is important.

Highlights:

• Pretreatment of GnRHa did not increase the live birth rate, clinical pregnancy rate, and miscarriage rate, or alter the perinatal complications compared to other endometrium preparation protocols.

What's done here:

• A retrospective cohort study designed to determine the optimal frozen-embryo transfer protocol in a tertiary academic medical center in Wuhan, China.
• The research was conducted on 1413 women with endometriosis who underwent oocyte aspiration and got a frozen-embryo transfer (2016 to 2020), all received natural cycle, hormonal treatment with or without GnRHa pretreatment endometrial preparation.
• The primary outcome measures were clinical pregnancy rate, miscarriage rate, multiple pregnancy rates, biochemical pregnancy rate, live birth rate, and ectopic pregnancy rate. 

Key Results:

• Infertile women were grouped according to the commonly used three types of endometrial preparation protocols: NC group (Natural Cycle, n=74), HRT group (Hormonal Replacement Therapy, n=389), and GnRHa+ HRT group ( GnRHa administration before HRT, n=950)).
• There were no statistical differences in pregnancy outcomes of those three protocol groups, including live birth rate, clinical pregnancy rate, miscarriage rate, multiple pregnancy rate, biochemical pregnancy rate, and ectopic pregnancy rate.
• 465 singleton pregnancies were evaluated for obstetric complications and adverse birth outcomes, whereas no statistical differences were reported between the three endometrial preparation protocols.
• The results showed that no protocol is superior to the others.

Lay Summary

Endometriosis can create infertility and may require treatment with assisted reproductive technology (ART) to induce pregnancy. However, the current literature rarely discusses the optimal endometrial preparation protocol in thawed-frozen embryo transfer (FET) cycles for endometriotic patients.

Dr.Jin. group from the Reproductive Medicine Center, Huanzong University of Science and Technology, Wuhan, China explored different endometrial preparation regimes on pregnancy and perinatal outcomes in women with endometriosis after FET cycles. They studied three commonly used endometrial preparation protocols in a retrospective cohort research that included 1413 women.  Natural cycle (74 women), hormonal replacement therapy(389 women), and GnRHa + HRT (950 women) were the three preparation protocols that comprised the study's three cohorts. They evaluated and statistically analyzed pregnancy and prenatal outcomes in this five-year retrospective study from 2015 to 2020.

After adjusting for possible confounding factors, no association was found between the three endometrial preparation protocols and clinical pregnancy outcomes. There were no statistical differences in any pregnancy outcomes, such as live birth rate, clinical pregnancy rate, miscarriage rate, biochemical pregnancy rate, and ectopic pregnancy rate.

Only 465 live births from singleton pregnancies were selected for analyzing perinatal outcomes such as low birth weight, small for age, large for gestational age, preterm birth, hypertensive disorders of the mother, placental disorders, and so on. No statistical differences were found in comparing three different preparation protocols. Regarding the statistical results, the authors concluded that HRT regimes combined with GnRHa did not provide any particular benefit superior to natural cycle or hormone replacement therapy alone.

Their article was recently published in "BMC open".

Research Source: https://pubmed.ncbi.nlm.nih.gov/36624470/