無細胞胎兒DNA可用于區分整倍體和非整倍體妊娠丟失

丹麥哥本哈根大學醫院Henriette Svarre Nielsen團隊研究了無細胞胎兒DNA用于遺傳評價的可行性。相關論文于2023年2月2日發表在《柳葉刀》雜志上。

四分之一的妊娠以流產告終。盡管對夫妻的影響有充分的文獻記載，但缺乏循證治療和預測模型。胎兒非整倍體與下一次成功妊娠的幾率更高，而整倍體妊娠丟失可能歸因于潛在的母體疾病。因此倍體診斷是有利的，但具有挑戰性，因為它們需要收集妊娠組織。來自母體血液的無細胞胎兒DNA（cffDNA）具有評估胎兒倍體狀態的潛力，但尚未對該方法進行大規模驗證。

在這項前瞻性隊列研究中，作為哥本哈根妊娠丟失（COPL）研究的一部分，丹麥公立醫院的三家婦科診所招募了妊娠丟失婦女。如果年齡大于18歲的女性在懷孕22周（即154天）之前發生了流產，并且通過超聲檢查確認了宮內妊娠（包括無胚囊），則有資格入選，并且排除了位置不明或葡萄胎妊娠的女性。在妊娠組織仍在原位或妊娠組織消失后24小時內采集母體血液，并通過cffDNA全基因組測序進行分析。妊娠組織的直接測序作為參考。

研究組納入了2020年11月12日至2022年5月1日，確診妊娠丟失的連續1000名女性。使用首批333名妊娠丟失婦女（2020年11月12日至2021年8月14日招募）的結果來評估基于cffDNA檢測的有效性。來自其他667名女性的結果被納入以評估cffDNA的表現和結果在1000名女性中的分布。胎兒的胎齡范圍為35-149天（平均70.5天，即10周加1天）。

與妊娠組織直接測序相比，基于cffDNA的測試對非整倍體檢測的敏感性為85%，特異性為93%。在1000個基于cffDNA的測試結果中，446個（45%）為整倍體，405個（41%）為非整倍體、37個（4%）為多重非整倍體，112個（11%）為不確定結果。333名婦女中有105名（32%）沒有收集到妊娠組織，或收集到一份被歸類為未知組織的樣本。

研究結果表明，對基于cffDNA的妊娠丟失檢測的驗證表明了區分整倍體和非整倍體妊娠丟失的方法的潛力和可行性，以改善臨床管理，并有利于未來的生殖醫學和婦女健康研究。

附：英文原文

Title: Cell-free fetal DNA for genetic evaluation in Copenhagen Pregnancy Loss Study (COPL): a prospective cohort study

Author: Tanja Schlaikjr Hartwig, Louise Ambye, Jennifer R Gruhn, Jesper Friis Petersen, Tine Wrnding, Letizia Amato, Andrew Chi-Ho Chan, Boyang Ji, Maiken Hemme Bro-Jrgensen, Lene Werge, Mette Marie Babiel Schmidt Petersen, Clara Brinkmann, Julie Birch Petersen, Morten Dun, Iben Bache, Markus J Herrgrd, Finn Stener Jrgensen, Eva R Hoffmann, Henriette Svarre Nielsen, Henriette Svarre Nielsen, Tanja Schlaikjr Hartwig, Nina la Cour Freiesleben, Finn Stener Jrgensen Jrgensen, Louise Ambye, Sofie Bliddal, Therese Juhlin Sndergaard, Sisse Rye Ostrowski, Erik Srensen, Margit Anita Hrup Larsen, Markus J. Herregrd, Eva Hoffmann, Jenny Gruhn, Andy Chi Ho Chan, Astrid Marie Kolte, David Westergaard, Unnur torsteinsdóttir, Kári Stefánsson, Hákon Jónsson, ólafur t. Magnússon, Valgerdur Steinthorsdottir, Lone Schmidt, Karsten Kristiansen, Pia Rrbk Kamstrup, Mette Nyegaard, Maria Christine Krog, Ellen Christine Leth Lkkegaard, Helle Ejdrup Bredkjr, Charlotte Wilken-Jensen

Issue&Volume: 2023-02-02

Abstract:

Background

One in four pregnancies end in a pregnancy loss. Although the effect on couples is well documented, evidence-based treatments and prediction models are absent. Fetal aneuploidy is associated with a higher chance of a next successful pregnancy compared with euploid pregnancy loss in which underlying maternal conditions might be causal. Ploidy diagnostics are therefore advantageous but challenging as they require collection of the pregnancy tissue. Cell-free fetal DNA (cffDNA) from maternal blood has the potential for evaluation of fetal ploidy status, but no large-scale validation of the method has been done.

Methods

In this prospective cohort study, women with a pregnancy loss were recruited as a part of the Copenhagen Pregnancy Loss (COPL) study from three gynaecological clinics at public hospitals in Denmark. Women were eligible for inclusion if older than 18 years with a pregnancy loss before gestational age 22 weeks (ie, 154 days) and with an intrauterine pregnancy confirmed by ultrasound (including anembryonic sac), and women with pregnancies of unknown location or molar pregnancies were excluded. Maternal blood was collected while pregnancy tissue was still in situ or within 24 h after pregnancy tissue had passed and was analysed by genome-wide sequencing of cffDNA. Direct sequencing of the pregnancy tissue was done as reference.

Findings

We included 1000 consecutive women, at the time of a pregnancy loss diagnosis, between Nov 12, 2020, and May 1, 2022. Results from the first 333 women with a pregnancy loss (recruited between Nov 12, 2020, and Aug 14, 2021) were used to evaluate the validity of cffDNA-based testing. Results from the other 667 women were included to evaluate cffDNA performance and result distribution in a larger cohort of 1000 women in total. Gestational age of fetus ranged from 35–149 days (mean of 70·5 days [SD 16·5], or 10 weeks plus 1 day). The cffDNA-based test had a sensitivity for aneuploidy detection of 85% (95% CI 79–90) and a specificity of 93% (95% CI 88–96) compared with direct sequencing of the pregnancy tissue. Among 1000 cffDNA-based test results, 446 (45%) were euploid, 405 (41%) aneuploid, 37 (4%) had multiple aneuploidies, and 112 (11%) were inconclusive. 105 (32%) of 333 women either did not manage to collect the pregnancy tissue or collected a sample classified as unknown tissue giving a high risk of being maternal.

Interpretation

This validation of cffDNA-based testing in pregnancy loss shows the potential and feasibility of the method to distinguish euploid and aneuploid pregnancy loss for improved clinical management and benefit of future reproductive medicine and women's health research.

DOI: 10.1016/S0140-6736(22)02610-1

Source: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(22)02610-1/fulltext