囊胚培養並非適用於所有患者的萬能策略。雖然延長培養時間可能提高多胚胎患者的胚胎選擇率和治療效率，但對於胚胎數量有限、高齡產婦或卵巢反應不良的患者，也可能增加失去存活胚胎的風險。因此，最佳移植策略應根據患者的預後、胚胎數量、先前體外受精史、治療目標以及實驗室的胚胎培養和冷凍保存能力進行個別化製定。

The Blastocyst Era: Is Blastocyst Transfer the Best Strategy for Every Patient?

Jing Wang, M.D., Ph.D.1 ∙ Ben W. Mol, M.D., Ph.D.2 ∙ Han Zhao, M.D., Ph.D.1

Taken together, current evidence suggests that blastocyst culture is not a one-size-fits-all strategy. Although extended culture may improve embryo selection and treatment efficiency in patients with multiple embryos, it may also increase the risk of losing viable embryos in those with limited embryo numbers, advanced maternal age, or poor ovarian response. The optimal transfer strategy should therefore be individualized according to patient prognosis, embryo availability, previous IVF history, treatment goals, and the laboratory's capabilities in embryo culture and cryopreservation, with patients with a strong ovarian response and many embryos probably benefiting from blastocyst culture. More level 1 evidence beyond women with good prognosis is needed. An important next step is an individual participant data (IPD) meta-analysis to identify patient characteristics that can guide personalized decisions between blastocyst and cleavage-stage transfer.

 雖然 NIPT 在 ART 受孕妊娠的特異性很高，但其在檢測常見胎兒染色體非整倍體（21,18,13)(特別是 21 三體綜合徵）方面的敏感性低於自然受孕妊娠。

Noninvasive prenatal testing as a prenatal screening test in pregnancies following assisted reproductive technologies: a diagnostic test accuracy systematic review and meta-analysis

Importance

The accuracy of the noninvasive prenatal testing (NIPT) for common trisomies remains unclear in pregnancies following assisted reproductive technology (ART), and the adoption of NIPT as a prenatal screening test in ART pregnancies has been cautious because of the absence of clear recommendations.

Objective

To estimate the accuracy of NIPT for screening for common chromosomal abnormalities compared with conventional karyotype or microarray testing in ART pregnancies.

Data sources

A comprehensive search of the following: PubMed, Scopus, and Embase.

Study selection and synthesis

A systematic review and meta-analysis was conducted, and cross-sectional and cohort studies of antenatal women who conceived following ART and opted for prenatal testing with NIPT were included.

Main outcomes

Pooled sensitivity and specificity of NIPT for common chromosomal abnormalities (trisomy 21, 18, and 13).

Results

We identified a total of 548 records through electronic searches and finally included 13 studies for quantitative synthesis. The pooled sensitivity and specificity for combined abnormalities in singleton ART pregnancies were 88.2% (95% confidence interval, [CI] 61.0%–97.3%) and 99.6% (95% CI 98.4%–99.9%), respectively. Similarly, for twin ART pregnancies, the pooled sensitivity and specificity for combined abnormalities were 88.2% (95% CI 66.4%–96.6%) and 99.8% (95% CI 99.6%–99.9%), respectively. The pooled sensitivity and specificity for trisomy 21 in singleton ART pregnancies were 87.2% (95% CI 59.0%–97.0%) and 99.7% (95% CI 98.8%–99.9%), respectively, whereas in ART twin pregnancies, the pooled sensitivity was 86.9% (95% CI 63.4%–96.2%) and the specificity was 99.8% (95% CI 99.6%–99.9%).

Conclusion and relevance

Although the specificity of NIPT is high in ART-conceived pregnancies, its sensitivity in the detection of common fetal chromosomal aneuploidy, in particular trisomy 21, is substantially lower than in naturally conceived pregnancies.