Role of gestational age at time of placental laser surgery in outcomes of twin-to-twin transfusion syndrome.

OBJECTIVE: There are conflicting data on whether fetoscopic laser photocoagulation of placental anastomoses (FLP) for treating twin-to-twin transfusion syndrome (TTTS) is associated with lower rates of overall survival. The objective of this study is to characterize survival and other associated morbidity after FLP across gestational ages of FLP. METHODS: This is a secondary analysis of prospectively collected data on patients with monochorionic-diamniotic twins that had FLP for TTTS at two centers between 2011 and 2022. Patients were divided into gestational age epochs for FLP before 18 wks, 18 0/7 - 19 6/7 wks, 20 0/7 - 21 6/7 wks, 22 0/7 - 23 6/7 wks, 24 0/7 - 25 6/7 wks and after 26 wks. Demographic characteristics, sonographic characteristics of TTTS and operative characteristics were compared across the gestational age epochs. Outcomes including overall survival, preterm delivery, preterm prelabor rupture of membranes (PPROM), intrauterine fetal demise (IUFD) and neonatal demise (NND) were also compared across gestational age epochs. Multivariate analysis was performed by fitting logistic regression models for these outcomes. Kaplan-Mejer curves were constructed to compare the interval from PPROM to delivery for each gestational age epoch. RESULTS: There were 768 patients that met inclusion criteria. The dual survival rate was 61.3% for FLP performed prior to 18 weeks compared to 78.0% - 86.7% across later gestational age epochs. This appears to be related to increased rates of donor IUFD following FLP performed before, versus after 18 weeks (28.0% vs. 9.3% - 14.1%). Rates of recipient IUFD/NND and donor NND were similar regardless of gestational age of FLP. Rates of PPROM were higher for earlier FLP, ranging from 45.6% for FLP before 18 weeks to 11.9% for FLP at 24 - 26 weeks gestational age. However, the gestational age of delivery was similar across gestational age epochs with a median of 31.7 weeks. In multivariate analysis, donor loss was independently associated with FLP before 18 weeks after adjusting for selective fetal growth restriction, Quintero stage and other covariates. PPROM and PTD were also associated with FLP before 18 weeks after adjusting for cervical length, placental location, trocar size, laser energy and amnioinfusion. CONCLUSION: FLP performed at earlier gestational ages is associated with lower overall survival, which is driven by higher risk of donor IUFD, as opposed to differences in PPROM or PTD. Counseling regarding survival should account for gestational age of presentation. This article is protected by copyright. All rights reserved.

Risk stratification for donor twin fetal death by evaluating middle cerebral artery in twin-to-twin transfusion syndrome in absence of twin anemia polycythemia sequence.

OBJECTIVE: To determine the association of high middle cerebral artery peak systolic velocity (MCA-PSV) with fetal demise in donor twins among pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) in the absence of twin anemia polycythemia sequence (TAPS). METHODS: This prospective cohort study included TTTS cases that underwent laser surgery between 2011 and 2022 at a single center. TAPS cases were excluded from the study. The primary objective was to explore the association of high MCA-PSV (>1.5 multiples of the median) with fetal demise of the donor twin among pregnancies complicated by TTTS. Secondary objectives were: 1) to evaluate if donor or recipient MCA-PSV is associated with an increased risk for their corresponding fetal death using receiving operator characteristic curve analysis; and 2) to compare the proportion of fetuses with low MCA pulsatility index among donor twins with high MCA-PSV and in those with normal MCA-PSV to evaluate the contribution of blood flow redistribution to high MCA-PSV. Multivariable and Poisson regression analysis were performed to explore the association of isolated high donor MCA-PSV and fetal demise, adjusted for TTTS stage, selective fetal growth restriction (sFGR), and other confounders. p<0.05 was considered significant. RESULTS: Out of 660 TTTS cases, donor MCA-PSV was unavailable in 48 (7.3%) cases. Of the remaining 612 patients, 9 (1.5%) were lost to follow-up, and 96 TAPS cases were excluded. High donor MCA-PSV was seen in 6.5% (33/507) of the study population. High donor MCA-PSV was an independent risk factor for donor fetal demise (adjusted relative risk (aRR) of 4.52; 95% CI: 2.72-7.50), adjusted for confounders. Regression analysis restricted to each Quintero TTTS stage demonstrated that high donor MCA-PSV was an independent risk factor for donor fetal demise in Quintero stage II (aRR of 14.21; 95% CI: 1.09-186.2) and Quintero stage III (aRR of 3.41; 95% CI: 1.82-6.41). Donor MCA-PSV was associated with donor fetal demise (AUC: 0.69; p<0.001), but recipient MCA-PSV was not associated with its corresponding fetal demise (AUC: 0.54; p=0.44). A higher proportion of donor twins in the group with high MCA-PSV had a low MCA pulsatility index than in those with normal MCA-PSV (33.3% vs. 15.5%; p=0.016). CONCLUSIONS: Elevated donor MCA-PSV without TAPS prior to laser surgery is associated with a 4-fold increased risk for donor fetal demise, adjusted for sFGR, TTTS stage, and other confounders. Doppler evaluation of donor MCA-PSV prior to laser surgery can further stratify TTTS staging to evaluate the risk for donor fetal demise. This article is protected by copyright. All rights reserved.

Fetal cardiovascular changes during open and fetoscopic in-utero spina bifida closure.

OBJECTIVE: Laparotomy-assisted fetoscopic closure of spina bifida utilizing heated-humidified carbon dioxide gas has been associated with less maternal morbidity than open in-utero spina bifida closure. Fetal cardiovascular changes during these surgical interventions are not well defined. Our objective was to compare fetal bradycardia (defined as fetal heart rate (FHR)<110 bpm over 10 minutes) and changes in umbilical artery Doppler parameters throughout open in-utero closure with those observed during laparotomy-assisted fetoscopic closure. METHODS: We conducted a prospective cohort study of 22 open and 46 fetoscopic consecutive in-utero closures between 2019 and 2023. Both cohorts had similar preoperative counseling and clinical management. FHR and umbilical artery velocimetry were systematically obtained during preoperative assessment, every 5 minutes during the intraoperative period, and in the postoperative assessment. FHR, pulsatility indexes and end-diastolic flows were segmented into hourly periods during surgery, and the lowest values were averaged for analysis. Umbilical vein maximum velocities were measured in the fetoscopic cohort. Each fetal heart rate recording time point was correlated to maternal parameters, including heart rate, systolic and diastolic blood pressures. RESULTS: Fetal bradycardia occurred in 4/22 cases (18.2%) of open in-utero closure and in 21/46 cases (45.7%) of fetoscopic closure. FHR gradually decreased in both cohorts after general anesthesia and decreased further during surgery. FHR were significantly lower after two hours of surgery in the fetoscopic closure than in the open in-utero closure group. In addition, the FHR (BPM) change in the final stages of the fetal surgery from the baseline FHR was significantly lower in the fetoscopic cohort (-32.3 (-35.7, -29.1)) compared to the open cohort (-23.5 (-28.1, -18.8)) (p=0.002). Abnormal end-diastolic flow (defined as absent or reversed end-diastolic flow) in the umbilical artery Doppler velocity occurred in 3/22 (13.6%) of the open closure cohort and in 23/46 (50%) of the fetoscopic closure cohort (p=0.004). There were no differences in umbilical artery end-diastolic flow and pulsatility index between closure techniques during the various stages of assessment. CONCLUSIONS: We observed a decrease in the FHR and abnormalities in umbilical artery Doppler parameters in both open in-utero and fetoscopic closure groups. Fetal bradycardia was more prominent during fetoscopic closure following heated-humidified carbon dioxide insufflation, but the FHR recovered after cessation of the heated-humidified carbon dioxide. Changes in FHR and umbilical artery Doppler parameters during in-utero spina bifida closure were observed to be transient, no cases required emergency delivery and no fetoscopic closure were converted to open closure. These observations should inform algorithms for perioperative management of fetal bradycardia associated with in-utero spina bifida closure. This article is protected by copyright. All rights reserved.

Management of large placental chorioangioma: two-port laser approach for fetal intervention.

OBJECTIVES: There is a paucity of literature providing evidence-based guidelines for the management of large placental chorioangioma (≥ 4 cm in diameter). The objectives of this study were to compare outcomes between patients managed expectantly and those undergoing in-utero intervention and to describe the different in-utero techniques used for cessation of blood flow to the tumor and the associated outcome. METHODS: This was a retrospective cohort study of 34 patients referred for the management of large placental chorioangioma in a single center between January 2011 and December 2022, who were managed expectantly or underwent in-utero intervention. In-utero intervention was performed when the fetus developed any signs of impending compromise, including high combined cardiac output (CCO), worsening polyhydramnios or abnormal fetal Doppler velocimetry findings. Interventions included radiofrequency ablation (RFA), interstitial laser ablation (ILA) and single-port or two-port fetoscopic laser photocoagulation (FLP). Treatment selection was dependent on the proximity of the tumor to the umbilical cord insertion (UCI) and placental location. The two-port technique was performed in patients with a chorioangioma with large feeding vessels (≥ 3 mm) located in the posterior placenta, in which one port was used for occlusion using bipolar forceps and the other port was used for laser photocoagulation of the feeding vessels downstream. The single-port technique was used for chorioangioma with small feeding vessels (< 3 mm) located in the posterior placenta. ILA or RFA was performed in cases with an anterior placenta. Supportive treatments, including amnioreduction and intrauterine transfusion (IUT), were performed for worsening polyhydramnios and suspected fetal anemia based on middle cerebral artery Doppler flow studies, respectively. Comparative statistical analysis between cases undergoing expectant management vs in-utero intervention was performed. Descriptive details were provided for patients who underwent in-utero intervention. RESULTS: Thirty-four cases of large chorioangioma were evaluated, of which 25 (73.5%) were managed expectantly and nine (26.5%) underwent intervention. The frequency of polyhydramnios was significantly higher in the intervention group compared with the expectant-management group (66.7% vs 8.0%, P < 0.001). The live-birth rate among expectantly managed cases with large chorioangioma was significantly higher compared with that in cases that underwent in-utero intervention (96.0% vs 62.5%, P = 0.01). In the intervention group, preoperative CCO was elevated in all cases with available information and preoperative hydrops was present in 33.3% (3/9) of cases. One patient experienced fetal demise following IUT prior to planned FLP. Among the remaining eight patients, four underwent two-port FLP, two underwent single-port FLP, one underwent ILA and one underwent both ILA and RFA. All three cases in which hydrops was present at the time of intervention resulted in fetal demise. CONCLUSIONS: In-utero interventions aimed at cessation of blood flow in the feeding vessels are a therapeutic option for the management of cases with large chorioangioma. The two-port percutaneous technique appears to improve the efficiency of FLP when a large chorioangioma with large feeding vessels is located in the posterior placenta. We propose that in-utero interventions for large chorioangioma should be initiated prior to the development of fetal hydrops. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.