Holder Kai N, Mormol Jessica S, Bakkensen Jennifer B, Pavone Mary Ellen, Goldman Kara N, Yeh Chen, Muhammad Lutfiyya N, Bernardi Lia A
Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
Department of Obstetrics and Gynecology, The Ohio State University, Columbus, OH, USA.
J Hum Reprod Sci. 2023 Oct-Dec;16(4):333-339. doi: 10.4103/jhrs.jhrs_125_23. Epub 2023 Dec 29.
While natural cycle frozen embryo transfer (NC-FET) is becoming increasingly common, significant practice variation exists in the use of ovulation induction medications, administration of ovulation trigger, and timing of embryo transfer without consensus as to the optimal protocol.
The objective of this study is to evaluate the association of key aspects of the NC-FET protocol with implantation, pregnancy and live birth.
This was a retrospective cohort study of blastocyst stage NC-FET cycles from October 2019 to July 2021 at a single academic fertility centre.
Protocols varied between cycles across three key parameters which were evaluated as primary predictors of cycle outcomes: (1) use of letrozole for mild ovarian stimulation/ovulation induction, (2) administration of exogenous ovulation trigger versus spontaneous luteinising hormone surge and (3) transfer timing based on ovulation trigger versus sequential progesterone monitoring. Primary outcomes included implantation rate, clinical pregnancy and ongoing pregnancy.
Generalised estimating equations were fitted to obtain adjusted odds ratios or rate ratios as appropriate with 95% confidence intervals for each outcome across the three primary predictors.
A total of 183 cycles from 170 unique patients were eligible for inclusion. The average implantation rate was 0.58, resulting in an overall clinical pregnancy and ongoing pregnancy rate of 59.0% and 51.4%, respectively. After adjusting for age at embryo freeze and history of a failed embryo transfer, there were no significant associations between any predictor and implantation rate, clinical pregnancy, ongoing pregnancy, or live birth.
In NC-FET, a variety of preparation and timing protocols may lead to comparable cycle outcomes, potentially allowing for flexibility on the basis of patient and physician preference. These findings warrant validation in a larger, randomised trial.
虽然自然周期冻融胚胎移植（NC-FET）越来越普遍，但在促排卵药物的使用、排卵触发的给药方式以及胚胎移植的时间安排上存在显著的实践差异，对于最佳方案尚无共识。
本研究的目的是评估NC-FET方案的关键方面与着床、妊娠和活产之间的关联。
这是一项对2019年10月至2021年7月在单一学术性生育中心进行的囊胚期NC-FET周期的回顾性队列研究。
各周期的方案在三个关键参数上有所不同，这三个参数被评估为周期结局的主要预测因素：（1）使用来曲唑进行轻度卵巢刺激/促排卵，（2）给予外源性排卵触发剂与自发性促黄体生成素激增，（3）基于排卵触发与序贯孕激素监测的移植时间。主要结局包括着床率、临床妊娠和持续妊娠。
采用广义估计方程，以获得适用于三个主要预测因素中每个结局的调整优势比或率比以及95%置信区间。
来自170名独特患者的总共183个周期符合纳入标准。平均着床率为0.58，总体临床妊娠率和持续妊娠率分别为59.0%和51.4%。在调整胚胎冷冻时的年龄和胚胎移植失败史后，任何预测因素与着床率、临床妊娠、持续妊娠或活产之间均无显著关联。
在NC-FET中，多种准备和时间方案可能导致相当的周期结局，这可能允许根据患者和医生的偏好进行灵活调整。这些发现需要在更大规模的随机试验中进行验证。
