Prediction of dual survival following fetoscopic laser photocoagulation for twin-twin transfusion syndrome

Survival rates in pregnancies complicated by twin-to-twin transfusion syndrome undergoing laser therapy: a systematic review and meta-analysis: Survival rates in twin-to-twin transfusion syndrome

OBJECTIVES

Twin-to-twin transfusion syndrome (TTTS) is associated with excess perinatal mortality and morbidity. Even though Quintero staging is commonly used to assess its severity, the limitations of its prognostic value have been highlighted by researchers over the years. Recent literature indicates that fetal survival, whether for both twins or at least one, following fetoscopic laser photocoagulation of the placental anastomoses is similar in TTTS Quintero stages I and II (combined) and III and IV (combined). In this context we perform a systematic review and meta-analysis of the published literature to elucidate the survival rate of twins according to the stage of TTTS and to compare the survival rates in pregnancies complicated by stage I and II (combined) vs those with stages III and IV (combined).

DATA SOURCES

Medline, Embase and Cochrane databases were searched.

STUDY ELIGIBILITY CRITERIA

The inclusion criteria were studies reporting the outcome of MCDA twin pregnancies with TTTS undergoing laser therapy according to the Quintero stage of the disease. The primary outcome was double survival at birth. The secondary outcomes were no survival, and survival of at least one twin. All the explored outcomes were reported according to the Quintero staging system. Furthermore, we aimed to compare all the observed outcomes in pregnancies complicated by TTTS affected by stage I and II vs those with stages III and IV.

STUDY APPRAISAL AND SYNTHESIS METHODS

Random-effect meta-analyses were used to combine data, and the results reported as pooled proportions or odd ratios (OR) with their 95% confidence intervals (CI).

RESULTS

26 studies were included. Survival of both fetuses was observed in 72.9% (95% CI 68.2-77.3) of pregnancies complicated by stage I, 67.9% (95% CI 62.3-73.3) with stage II, 48.1% (95% CI 42.5-53.8) with stage III, and 53.4% (95% CI 42.5-64.3) with stage IV TTTS (Table 3). At least one survivor was reported in 89.4% (95% CI 86.9-91.9) of cases with stage I, 87.1% (95% CI 82.9-90.7) with stage II, 77.3% (95% CI 71.7-82.5) with stage III, and 80.1% (95% CI 69.4-89.0) with stage 4. The corresponding figures for no survivors were 10.7% (95% CI 7.7-14.0), 11.4% (95% CI 7.8-15.6), 20.4% (95% CI 15.6-25.8), and 16.7% (95% CI 8.3-27.2), respectively. When comparing the different outcomes according to the different TTTS stages, there was no significant difference in the incidence of double survival (p=0.933), at least one survivor (p=0.688), and no survivors (p=0.866) between stages I and II TTTS. There was also no significant difference in the incidence of double survival (p=0.201), at least one survivor (p=0.380), and no survivors (p=0.947) between stages III and IV. Conversely, when comparing the outcome of pregnancies with stage I/II (combined) vs stages III/IV (combined), the incidence of double survival was significantly higher in pregnancies with stages I/II (OR 2.19; 95% CI 1.9-2.6, p<0.001) (Table 5). Likewise, the incidence of at least one survivor was significantly higher (OR 1.85, 95% CI 1.5-2.6, p<0.001) while that of no survivor (OR 0.56, 95% CI 0.4-0.7, p<0.001) significantly lower in pregnancies with stages I/II compared to III/IV.

CONCLUSION

Perinatal survival of MCDA twin pregnancies complicated by TTTS and treated with fetoscopic laser coagulation of placental anastomoses is not significantly different between stages I and II, or between stages III and IV, apart from a higher chance of one survivor in stage III compared to stage IV. The findings from this systematic review will be useful in individualised risk assessment of twin pregnancies complicated by TTTS and tailored counselling of the parents. It also highlights the need for studies aimed at better characterizing the prenatal risk factors for mortality in pregnancies complicated by TTTS.

CONDENSATION

Perinatal survival of MCDA twin pregnancies complicated by TTTS and treated with fetoscopic laser coagulation of placental anastomoses is not significantly different between stages I and II, or between stages III and IV.

Perinatal outcomes of fetoscopic selective laser photocoagulation for spontaneous twin-anemia polycythemia sequence

OBJECTIVES

Antenatal management of monochorionic pregnancies complicated by twin anemia polycythemia sequence (TAPS) remains sub-optimally defined. Our objective was to evaluate the safety and efficacy of fetoscopic selective laser photocoagulation with respect to fetal and neonatal survival.

METHODS

A case series is reported with patients referred to the Texas Children's Fetal Center for evaluation and management of suspected spontaneous TAPS without concomitant twin-to-twin syndrome from 2014 to 2023. All evaluations were performed by our team and patients with stage II-IV TAPS were offered expectant management, intrauterine transfusion, or laser therapy. Cases of post-laser TAPS were excluded from this study. Pregnancy and neonatal outcomes were obtained from electronic medical records.

RESULTS

During a 10-year time period, 18 patients presented to our center for the management of TAPS. Thirteen patients had stage II-IV TAPS (13/18, 72%) and elected to proceed with laser photocoagulation. All procedures were completed, and "solomonization" was performed for 12/13. Normalization of middle cerebral artery Dopplers in both fetuses was noted after all cases. There was one intrauterine fetal death of the 26 viable fetuses after laser treatment, which was complicated by selective growth restriction. Most patients (12/13) were delivered by Cesarean section at a mean gestational age of 29 ± 3 weeks. Subsequently, there was one ex-donor neonatal death in an infant who had prenatal hydrops. Overall, 30-day postnatal survival was 24/26 fetuses (92.3%).

CONCLUSIONS

In the setting of spontaneous TAPS, laser therapy is feasible and appears to be an effective approach with overall favorable perinatal outcomes.

Consensus protocol for management of early and late twin-twin transfusion syndrome: Delphi study

OBJECTIVE

Fetoscopic laser photocoagulation (FLP) is a well-established treatment for twin-twin transfusion syndrome (TTTS) between 16 and 26 weeks' gestation. High-quality evidence and guidelines regarding the optimal clinical management of very early (prior to 16 weeks), early (between 16 and 18 weeks) and late (after 26 weeks) TTTS are lacking. The aim of this study was to construct a structured expert-based clinical consensus for the management of early and late TTTS.

METHODS

A Delphi procedure was conducted among an international panel of experts. Participants were chosen based on their clinical expertise, affiliation and relevant publications. A four-round Delphi survey was conducted using an online platform and responses were collected anonymously. In the first round, a core group of experts was asked to answer open-ended questions regarding the indications, timing and modes of treatment for early and late TTTS. In the second and third rounds, participants were asked to grade each statement on a Likert scale (1, completely disagree; 5, completely agree) and to add any suggestions or modifications. At the end of each round, the median score for each statement was calculated. Statements with a median grade of 5 without suggestions for change were accepted as the consensus. Statements with a median grade of 3 or less were excluded from the Delphi process. Statements with a median grade of 4 were modified according to suggestions and reconsidered in the next round. In the last round, participants were asked to agree or disagree with the statements, and those with more than 70% agreement without suggestions for change were considered the consensus.

RESULTS

A total of 122 experts met the inclusion criteria and were invited to participate, of whom 53 (43.4%) agreed to take part in the study. Of those, 75.5% completed all four rounds. A consensus on the optimal management of early and late TTTS was obtained. FLP can be offered as early as 15 weeks' gestation for selected cases, and can be considered up to 28 weeks. Between 16 and 18 weeks, management should be tailored according to Doppler findings.

CONCLUSIONS

A consensus-based treatment protocol for early and late TTTS was agreed upon by a panel of experts. This protocol should be modified at the discretion of the operator, according to their experience and the specific demands of each case. This should advance the quality of future studies, guide clinical practice and improve patient care. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Predictors of fetal death, neonatal survival and neurological outcomes in severe twin-twin transfusion syndrome treated by laser ablation of placental vessels

OBJECTIVES

To identify predictors of outcomes in severe twin oligo-polyhydramnios sequence (TOPS) with or without twin anemia-polycythemia sequence (TAPS) and/or selective fetal growth restriction (SFGR) treated by laser ablation of placental vessels (LAPV).

METHODS

Analysis of cases treated from 2011 to 2022. Variables evaluated Prenatal predictors: stages of TOPS, presence of TAPS and/or SFGR; pre-LAPV fetal ultrasound parameters; peri-LAPV variables. Perinatal predictors: GA at birth; birthweight; Apgar scores; transfontanellar ultrasonography (TFUS).

OUTCOME VARIABLES

fetal death, neonatal survival, infant's neurodevelopment. Binary logistic regression analyses were performed to detect predictors of outcomes.

RESULTS

265 cases were included. Predictors of post-LAPV donor fetus' death were delta EFW (p:0.045) and absent/reverse end-diastolic flow in the umbilical artery (AREDF-UA) (p < 0.001). The predictor of post-LAPV recipient fetus' death was hydrops (p:0.009). Predictors of neonatal survival were GA at birth and Apgar scores. Predictors of infant's neurodevelopment were TFUS and pre-LAPV middle cerebral artery Doppler (MCAD) for the donor twin; and pre-LAPV ductus venosus' flow and MCAD for the recipient twin.

CONCLUSIONS

Prediction of fetal death, neonatal survival and infant's neurodevelopment is possible in cases of TOPS associated or not with SFGR and/or TAPS that were treated by LAPV.

Laser fetoscopy ablation for twin-twin transfusion syndrome may reduce the risk of ROP

PURPOSE

Twin-twin transfusion syndrome (TTTS) is a condition wherein monochorionic twins share a common placenta with placental anastomoses between the two foetal circulations. Most infants who survive TTTS are born prematurely. This study aimed to determine whether fetoscopic laser ablation (FLA) can reduce the risk of retinopathy of prematurity (ROP) and whether TTTS was a risk factor for ROP.

METHODS

This single-centre, retrospective, comparative study included 32 monochorionic twins with TTTS matched for gestational age, birthweight and sex to premature twins and singletons without TTTS (n = 68; twins, n = 34; and singletons, n = 34) born between 2003 and 2022. A single ophthalmologist recorded the fundus findings. FLA was performed using Solomon's technique to separate the vascular systems of the twins with TTTS.

RESULTS

The gestational age and weight of premature infants with TTTS treated with FLA were significantly higher than those of untreated infants (p = 0.001 and p = 0.001, respectively); however, the hyaline membrane grade was lower (p = 0.004). A significant increase in weight (g/day) (p = 0.002) and lesser avascular area in the peripheral temporal retina (p = 0.045) was observed at postnatal week 4. The risk of ROP in the FLA group was 2.6 times (13.3% vs. 35.3%) lower than that in the non-FLA group; however, this difference was not significant. The incidence of any stage of ROP (25% vs. 18%) and treatment for ROP type 1 (6.25% vs. 5.9%) did not differ significantly between monochorionic twins with TTTS and premature infants without TTTS.

CONCLUSION

The gestational age of premature infants with TTTS treated with FLA was higher than that of untreated infants. Moreover, a reduction in complications of prematurity was also observed. Laser fetoscopy in twin-twin transfusion syndrome may reduce the risk of ROP, but the difference was not statistically significant in this small study.

Doppler Finding, Cardiovascular Function Assessment, and Fetuses' Survival Following the Fetoscopic Laser in Twin-to-Twin Transfusion Syndrome

Introduction: This study aimed to evaluate the effectiveness of selective laser photocoagulation of communicating vessels (SLPCV) on cardiac function in twins with twin-to-twin transfusion syndrome (TTTS). Methods: This retrospective cohort study evaluated 178 women with twin pregnancies complicated with TTTS and scheduled for SLPCV between 16 and 26 weeks of gestation. The severity of TTTS was determined by Quintero staging and the severity of cardiovascular disorders by the CHOP (Children's Hospital of Philadelphia) score. Patient survival was evaluated through a one-month-after-birth follow-up of fetuses. Results: The study revealed significant improvements in Doppler indices in both donors and recipients after SLPCV. The CHOP score also significantly decreased after the intervention. One-month-after-birth survival rates were 55.1% in donors and 56.7% in recipients. Some Doppler indexes of fetuses before SLPCV could predict survival until one month after birth. Conclusion: The study suggests that SLPCV can improve cardiac function in fetuses with TTTS and that some Doppler indexes can predict survival outcomes. Additionally, the severity of TTTS can be a powerful indicator of the severity of cardiovascular complications.

Effect of Gestational Age at Fetoscopic Laser Photocoagulation on Perinatal Outcomes for Patients with Twin-Twin Transfusion Syndrome

PURPOSE

The aim of this study was to evaluate the effect of gestational age (GA) at the time of fetoscopic laser photocoagulation (FLP) for severe twin-twin transfusion syndrome (TTTS) on perinatal outcomes in a single center in Taiwan.

MATERIALS AND METHODS

Severe TTTS was defined as a diagnosis of TTTS before a GA of 26 weeks. Consecutive cases of severe TTTS treated at our hospital with FLP between October 2005 and September 2022 were included. The evaluated perinatal outcomes were preterm premature rupture of membranes (PPROM) within 21 days of FLP, survival 28 days after delivery, GA at delivery, and neonatal brain sonographic imaging findings within 1 month of delivery.

RESULTS

We included 197 severe TTTS cases; the mean GA at the time of FLP was 20.6 weeks. After the cases were divided into cases of FLP at early (below 20 weeks) and late GAs (more than 20 weeks), the early-GA group was discovered to be associated with a deeper maximum vertical pocket in the recipient twin, a higher rate of PPROM development within 21 days of FLP, and lower rates of survival of one or both twins. In the cases of stage I TTTS, the rate of PPROM within 21 days of FLP was higher in the group that underwent FLP at an early GA than in the group that underwent FLP at a late GA (50% (3/6) vs. 0% (0/24), respectively, p = 0.005). Logistic regression analysis revealed that the GA at the time of FLP and the cervical length before FLP is implemented are significantly associated with the survival of one twin and the incidence of PPROM development within 21 days of FLP. The GA at the time of FLP, the cervical length before FLP, and TTTS being stage III TTTS were associated with the survival of both twins after FLP. Neonatal brain image anomalies were associated with GA at delivery.

CONCLUSIONS

FLP being performed at an earlier GA is a risk factor for lower fetal survival and PPROM development within 21 days of FLP in cases of severe TTTS. Delaying FLP for cases involving stage I TTTS diagnosed at an early GA without risk factors, such as maternal symptoms, cardiac overload in the recipient twin, or a short cervical length, may be considered, but whether delaying FLP would improve surgical outcomes and, if so, how long the delay should be may need further trials to answer.