Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, CA (Dr Nguyen, Ms Masri, and Dr Chmait).
Intermountain Healthcare, Salt Lake City, UT (Dr Monson); Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Utah Health, Salt Lake City, UT (Dr Monson).
Am J Obstet Gynecol MFM. 2023 Sep;5(9):101082. doi: 10.1016/j.ajogmf.2023.101082. Epub 2023 Jul 6.
Subclassification of monochorionic twins with selective fetal growth restriction type II into IIa vs IIb has been proposed because of differing neonatal survival outcomes of the fetus with growth restriction after laser surgery based on preoperative Doppler findings in the middle cerebral artery and ductus venosus. There is substantial clinical overlap between selective fetal growth restriction and twin-twin transfusion syndrome.
This study aimed to compare donor twin neonatal survival after laser surgery in cases of twin-twin transfusion syndrome with concomitant donor fetal growth restriction type IIa vs IIb.
This was a retrospective study of monochorionic multifetal pregnancies treated with laser surgery for stage III twin-twin transfusion syndrome and concomitant donor twin fetal growth restriction type II at a referral center from 2006 to 2021. Donor fetal growth restriction type II was defined as having an estimated fetal weight <10th percentile with persistent absent and/or reversed end-diastolic velocity in the umbilical artery. Moreover, patients were subclassified as type IIa (having normal middle cerebral artery peak systolic velocities and ductus venosus Doppler waveforms) vs type IIb (having middle cerebral artery peak systolic velocities ≥1.5 multiples of the median and/or ductus venosus with persistent absent or reversed atrial systolic flow). This study compared 30-day neonatal survival of the donor twin by fetal growth restriction type IIa vs IIb using logistic regression to adjust for relevant preoperative covariates (P<.10 in bivariate analysis).
Of 919 patients who underwent laser surgery for twin-twin transfusion syndrome, 262 had sstage III donor or donor and recipient twin-twin transfusion syndrome; of these patients, 189 (20.6%) had concomitant donor fetal growth restriction type II. Moreover, 12 patients met the exclusion criteria, yielding 177 patients (19.3%) who composed the study cohort. Patients were subclassified as donor fetal growth restriction type IIa (146 [82%]) vs type IIb (31 [18%]). Donor neonatal survival for fetal growth restriction type IIa vs IIb was 71.2% vs 41.9% (P=.003). Recipient neonatal survival did not differ between the 2 types (P=1.000). Patients classified with twin-twin transfusion syndrome and concomitant donor fetal growth restriction type IIb were 66% less likely to have neonatal survival of the donor after laser surgery (adjusted odds ratio, 0.34; 95% confidence interval, 0.15-0.80; P=.0127). The logistic regression model was adjusted for gestational age at the procedure, estimated fetal weight percent discordance, and nulliparity. The c-statistic was 0.702.
For patients with stage III twin-twin transfusion syndrome and concurrent donor fetal growth restriction with persistent absent or reversed end-diastolic velocity in the umbilical artery (ie, fetal growth restriction type II), subclassification into fetal growth restriction type IIb based on elevated middle cerebral artery peak systolic velocity and/or abnormal ductus venosus flow in the donor conveyed poorer prognosis. Although donor neonatal survival after laser surgery was lower for patients with stage III twin-twin transfusion syndrome with donor fetal growth restriction type IIb than patients with stage III twin-twin transfusion syndrome with donor fetal growth restriction with type IIa, laser surgery for fetal growth restriction type IIb in the setting of twin-twin transfusion syndrome (as opposed to pure selective fetal growth restriction type IIb) still allows for the possibility of dual survivorship and should be offered with shared decision-making when counseling patients on management options.
根据术前大脑中动脉和静脉导管多普勒检查的结果，将选择性胎儿生长受限 II 型的单绒毛膜双胞胎分为 IIa 与 IIb 亚类，因为激光手术后生长受限胎儿的新生儿存活率存在差异。选择性胎儿生长受限与双胎输血综合征有很大的临床重叠。
本研究旨在比较双胎输血综合征合并伴发的胎儿生长受限 IIa 与 IIb 型的受血儿在激光手术后的供体儿新生儿存活率。
这是一项回顾性研究，纳入了 2006 年至 2021 年在转诊中心接受激光手术治疗 III 期双胎输血综合征且伴有伴发的胎儿生长受限 II 型的多胎妊娠。胎儿生长受限 II 型的定义为估计胎儿体重<第 10 百分位数，且脐动脉呈持续无舒张末期血流或反向舒张末期血流。此外，将患者分为 IIa 型（大脑中动脉峰值收缩速度和静脉导管多普勒波形正常）和 IIb 型（大脑中动脉峰值收缩速度≥1.5 倍中位数和/或静脉导管呈持续无心房收缩或反向血流）。本研究通过逻辑回归比较了胎儿生长受限 IIa 与 IIb 型供体儿的 30 天新生儿存活率，以调整相关术前协变量（双变量分析中 P<.10）。
在 919 例接受激光手术治疗的双胎输血综合征患者中，262 例为 III 期供体或供体和受者双胎输血综合征；其中 189 例（20.6%）伴有伴发的胎儿生长受限 II 型。此外，有 12 例患者符合排除标准，最终有 177 例（19.3%）患者纳入研究队列。患者被分为胎儿生长受限 IIa 型（146 例[82%]）和 IIb 型（31 例[18%]）。胎儿生长受限 IIa 与 IIb 型的供体儿新生儿存活率分别为 71.2%和 41.9%（P=.003）。两种类型的受体儿新生儿存活率无差异（P=1.000）。分类为双胎输血综合征合并伴发的胎儿生长受限 IIb 型的患者接受激光手术后供体儿存活的可能性降低 66%（调整优势比，0.34；95%置信区间，0.15-0.80；P=.0127）。逻辑回归模型调整了手术时的孕龄、估计胎儿体重差异百分比和初产妇。C 统计量为 0.702。
对于患有 III 期双胎输血综合征且伴有脐动脉持续无舒张末期血流或反向舒张末期血流的伴发胎儿生长受限（即胎儿生长受限 II 型）的患者，根据大脑中动脉峰值收缩速度升高和/或静脉导管血流异常对胎儿生长受限进行 IIb 型亚分类提示预后更差。尽管与 III 期双胎输血综合征伴发胎儿生长受限 IIa 型相比，III 期双胎输血综合征伴发胎儿生长受限 IIb 型患者的激光手术后供体儿存活率较低，但对于双胎输血综合征（而非单纯选择性胎儿生长受限 IIb 型）中的胎儿生长受限 IIb 型患者，激光手术仍然有可能实现双存活，并在向患者提供管理方案的咨询时，应进行共同决策。
