Single fetal demise following fetoscopic ablation for twin-to-twin transfusion syndrome—cohort study, systematic review, and meta-analysis

Abstract

Several studies have assessed preoperative and operative factors associated with fetal demise after laser for TTTS, yet these findings are not completely conclusive. This study aimed to identify risk factors for single fetal demise (recipient and donor twins) after fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome. We searched PubMed, Scopus, and Web of Science systematically from the inception of the database to June 2020. We conducted a systemic review on studies investigating risk factors for fetal demise (donor and/or recipient) after fetoscopic laser photocoagulation in monochorionic pregnancies complicated with twin-to-twin transfusion syndrome. Initially, we investigated the cohort of women with twin-to-twin transfusion syndrome that underwent fetoscopic laser photocoagulation at our 2 high-volume fetal centers between 2012 and 2020 to identify risk factors for donor demise and recipient demise. Furthermore, we conducted a systematic review of the literature to better characterize these factors. Among studies that met the entry criteria, multiple preoperative and operative factors were tabulated. The random-effect model was used to pool the standardized mean differences or odds ratios and corresponding 95% confidence intervals. Heterogeneity was assessed using the I2 value. A total of 514 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were included in the final analysis. Following the logistic regression, factors that remained significant for donor demise were selective fetal growth restriction (odds ratio, 1.9; 95% confidence interval, 1.3-2.8; P=.001) and umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.06; 95% confidence interval, 1.2-3.4; P=.004). A significant factor associated with recipient demise was absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 1.74; 95% confidence interval, 1.07-3.13; P=.04). Data from 23 studies and our current cohort were included. A total of 4892 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were analyzed for risk factors for donor demise, and 4594 pregnancies with twin-to-twin transfusion syndrome were analyzed for recipient demise. Among studies, the overall incidence rates ranged from 10.9% to 35.8% for donor demise and 7.3% to 24.5% for recipient demise. Significant risk factors for donor demise were intertwin estimated fetal weight discordance of >25% (odds ratio, 1.86; 95% confidence interval, 1.44-2.4; I2, 0.0%), selective fetal growth restriction (odds ratio, 1.78; 95% confidence interval, 1.4-2.27; I2, 0.0%), twin-to-twin transfusion syndrome stage III (odds ratio, 2.18; 95% confidence interval, 1.53-3.12; I2, 0.0%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.31; 95% confidence interval, 1.9-2.8; I2, 23.7%), absent or reversed a-wave in the ductus venosus of the donor (odds ratio, 1.83; 95% confidence interval, 1.45-2.3; I2, 0.0%), and presence of arterioarterial anastomoses (odds ratio, 2.81; 95% confidence interval, 1.35-5.85; I2, 90.7%). Sequential selective coagulation was protective against donor demise (odds ratio, 0.31; 95% confidence interval, 0.16-0.58; I2, 0.0%). Significant risk factors for recipient demise were twin-to-twin transfusion syndrome stage IV (odds ratio, 2.18; 95% confidence interval, 1.01-4.6; I2, 16.5%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the recipient (odds ratio, 2.68; 95% confidence interval, 1.91-3.74; I2, 0.0%), absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 2.37; 95% confidence interval, 1.55-3.64; I2, 60.2%), and middle cerebral artery peak systolic velocity of >1.5 multiple of the median (odds ratio, 3.06; 95% confidence interval, 1.36-6.88; I2, 0.0%). Abnormal blood flow patterns represented by abnormal Doppler studies and low fetal weight were associated with single fetal demise in women with twin-to-twin transfusion syndrome undergoing laser therapy. Although sequential selective coagulation was protective against donor demise, the presence of arterioarterial anastomoses was considerably associated with donor demise. This meta-analysis extensively investigated the association of a wide range of preoperative and operative factors with fetal demise. These findings may be important inpatient counseling, in further understanding the disease, and perhaps in improving surgical techniques.