Prenatal risk factors for urgent atrial septostomy at birth in fetuses with transposition of the great arteries: a systematic review and meta-analysis

<b>Purpose of the article.</b> To explore the role of fetal echocardiography in predicting the risk of urgent balloon atrial septostomy (BAS) at birth in fetuses diagnosed with transposition of the great arteries (TGA). Medline, Embase, and Cochrane databases were searched. The primary aim was to explore the differences in prenatal echocardiographic parameters among fetuses diagnosed with TGA that required urgent BAS within 24 h of birth due to life-threatening cyanosis compared to those who did not require such procedure. Random-effect meta-analyses were used to compute the data. Six studies (292 fetuses) were included. Restrictive appearance of the FO was present in 64.5% (95% CI = 39.8–85.7) of fetuses with TGA requiring BAS at birth compared to 7.9% (95% CI = 2.1–16.8) not requiring such procedure (OR = 71.1; 95% CI = 8.3–608.5, <i>p</i> &lt; .0001). Hypermobile appearance of the atrial septum was present in 39.1% (95% CI = 26.4–56.5) of fetuses requiring BAS at birth compared to 9.8% (95% CI = 1.4–24.3) of those which did (OR 3.6; 95% CI = 1.4–9.0, <i>p</i> = .05). There was no difference in the prevalence of redundant (<i>p</i> = .374) or fixed (<i>p</i> = .051) atrial septum, bidirectional flow in the DA (<i>p</i> = .26) or an abnormal size of the DA (<i>p</i> = .06) in fetuses requiring urgent BAS at birth compared to those which did not. Mean (±SD) size of the right atrium was smaller in the fetuses with TGA undergoing urgent BAS at birth (23.4 ± 6.7) compared to those which did not (29.2 ± 6.2, <i>p</i> = .01). The mean (±SD) ratio between the FO and the aortic valve diameters (1.01 ± 0.41 versus 1.41 ± 0.43, <i>p</i> = .009) and the mean (±SD) ratio between the FO diameter and the septal length (0.36 ± 0.13 versus 0.51 ± 0.14, <i>p</i> = .001) were significantly smaller in fetuses requiring compared to those not undergoing urgent BAS at birth. The diagnostic accuracy of each independent ultrasound marker of the need for urgent BAS showed an overall good specificity but a low sensitivity. Fetal echocardiography prior to birth can stratify the risk of BAS in fetuses with TGA. Further studies are needed to validate these findings and build individualized multiparametric predictive models in order to more accurately identify those fetuses with TGA at a higher risk of urgent BAS after birth.

**研究目的**：探讨胎儿超声心动图（fetal echocardiography）在预测诊断为大动脉转位（transposition of the great arteries, TGA）的胎儿出生时需接受紧急球囊房间隔造口术（balloon atrial septostomy, BAS）风险中的作用。本研究检索了Medline、Embase及Cochrane数据库，核心研究目标为对比两类TGA胎儿的产前超声心动图参数差异：一类是因危及生命的发绀需在出生后24小时内接受紧急BAS的胎儿，另一类是无需接受该手术的胎儿。研究采用随机效应荟萃分析（random-effect meta-analyses）对数据进行整合分析。最终纳入6项研究，共计292例胎儿。结果显示，需出生时接受BAS的TGA胎儿中，64.5%（95%置信区间（confidence interval, CI）：39.8~85.7）存在卵圆孔（foramen ovale, FO）限制性表现，而无需接受该手术的胎儿中该比例仅为7.9%（95%CI：2.1~16.8）（比值比（odds ratio, OR）=71.1；95%CI：8.3~608.5，P<0.0001）。需出生时接受BAS的胎儿中，39.1%（95%CI：26.4~56.5）存在房间隔活动度过大表现，而无需该手术的胎儿中该比例为9.8%（95%CI：1.4~24.3）（OR=3.6；95%CI：1.4~9.0，P=0.05）。而在需接受紧急BAS的胎儿与无需该手术的胎儿之间，房间隔冗余（P=0.374）、房间隔固定（P=0.051）、动脉导管（ductus arteriosus, DA）双向血流（P=0.26）以及动脉导管管径异常（P=0.06）的发生率均无显著统计学差异。需出生时接受紧急BAS的TGA胎儿的右心房平均（±标准差）管径更小，为23.4±6.7，而无需该手术的胎儿为29.2±6.2（P=0.01）。需接受紧急BAS的胎儿，其卵圆孔与主动脉瓣直径比值的平均值（±标准差）为1.01±0.41，相较于无需该手术的胎儿的1.41±0.43（P=0.009）；其卵圆孔直径与房间隔长度比值的平均值（±标准差）为0.36±0.13，相较于无需该手术的胎儿的0.51±0.14（P=0.001），两项指标均显著低于无需该手术的胎儿。各项针对紧急BAS需求的独立超声标志物的诊断准确性均表现出较高的特异性，但敏感性较低。产前胎儿超声心动图可对TGA胎儿出生后需接受BAS的风险进行分层。未来仍需开展进一步研究以验证上述发现，并构建个体化多参数预测模型，从而更精准地识别出生后需接受紧急BAS的高风险TGA胎儿。