Prevalence of right ventricular outflow tract abnormalities among recipients in twin-twin transfusion syndrome after fetoscopic laser surgery in 90 consecutive cases

Incidence, prognosis, and perinatal outcomes of and risk factors for severe twin–twin transfusion syndrome with right ventricular outflow tract obstruction in the recipient twin after fetoscopic laser photocoagulation

Background

Right ventricular outflow tract obstruction (RVOTO) is the most frequently encountered congenital heart disease in patients with twin –twin transfusion syndrome (TTTS) and is especially prevalent in the recipient twin. In this retrospective study, we evaluated the incidence, prognosis, postnatal management, and perinatal outcomes of and risk factors for RVOTO in the recipient twin in severe TTTS cases which diagnosed before 26 weeks after fetoscopic laser photocoagulation (FLP) at a single center in Taiwan.

Methods

RVOTO was diagnosed using fetal or postnatal echocardiography. The fetal outcomes evaluated were perinatal survival rate, neonatal brain image anomalies rate, gestational age at delivery, and birth weight.

Results

Total 187 severe TTTS cases were included; 14 (7.49%) had a recipient twin with RVOTO (12 cases of pulmonary stenosis and 2 of pulmonary atresia). Of these 14 cases, 3 (21.4%) demonstrated improvements in outflow obstruction after FLP, and 11 (78.6%) resulted in perinatal survival. Of the 11 survivors, 5 (45.5%) received transcatheter balloon valvuloplasty to alleviate the RVOTO. The perinatal survival rate, gestational age at delivery, neonatal brain image anomaly rate, and birth weights did not significantly differ between the groups in which the recipient twin had versus did not have RVOTO. Generally, the recipient twin had RVOTO received FLP at a younger gestational age (in weeks; 19.3 ± 2.4 vs. 20.7 ± 2.6, p = 0.048) and had a higher percentage of cases at Quintero stage IV (50.0% vs. 12.1%, p < 0.001) than those in which the recipient twin did not have with RVOTO. Using logistic regression, we discovered that FLP at a younger gestational age (p = 0.046, odds ratio = 0.779) and TTTS at Quintero stage IV (p = 0.001, odds ratio = 7.206) were risk factors for the recipient twin developing RVOTO after FLP in severe TTTS cases.

Conclusions

The post-FLP perinatal outcomes of cases of severe TTTS in which the recipient twin had versus did not have RVOTO were comparable in this study, which may have been due to the similar gestational ages at delivery and strong influence of high Quintero stages (stages III and IV).

Perinatal outcome of pregnancy complicated by twin anemia-polycythemia sequence: systematic review and meta-analysis

OBJECTIVE

To report the perinatal outcome of monochorionic diamniotic (MCDA) twin pregnancies complicated by twin anemia-polycythemia sequence (TAPS), according to the type of TAPS (spontaneous or postlaser) and the management option adopted.

METHODS

MEDLINE, EMBASE and The Cochrane Library databases were searched for studies reporting on the outcome of twin pregnancies complicated by TAPS. Inclusion criteria were non-anomalous MCDA twin pregnancies with a diagnosis of TAPS. The primary outcome was perinatal mortality; secondary outcomes were neonatal morbidity and preterm birth (PTB). The outcomes were stratified according to the type of TAPS (spontaneous or following laser treatment for twin-twin transfusion syndrome) and the management option adopted (expectant, laser surgery, intrauterine transfusion (IUT) or selective reduction (SR)). Random-effects meta-analysis of proportions was used to analyze the data.

RESULTS

Perinatal outcome was assessed according to whether TAPS occurred spontaneously or after laser treatment in 506 pregnancies (38 studies). Intrauterine death (IUD) occurred in 5.2% (95% CI, 3.6-7.1%) of twins with spontaneous TAPS and in 10.2% (95% CI, 7.4-13.3%) of those with postlaser TAPS, while the corresponding rates of neonatal death were 4.0% (95% CI, 2.6-5.7%) and 9.2% (95% CI, 6.6-12.3%), respectively. Severe neonatal morbidity occurred in 29.3% (95% CI, 25.6-33.1%) of twins after spontaneous TAPS and in 33.3% (95% CI, 17.4-51.8%) after postlaser TAPS, while the corresponding rates of severe neurological morbidity were 4.0% (95% CI, 3.5-5.7%) and 11.1% (95% CI, 6.2-17.2%), respectively. PTB complicated 86.3% (95% CI, 77.2-93.3%) of pregnancies with spontaneous TAPS and all cases with postlaser TAPS (100% (95% CI, 84.3-100%)). Iatrogenic PTB was more frequent than spontaneous PTB in both groups. Perinatal outcome was assessed according to the management option adopted in 417 pregnancies (21 studies). IUD occurred in 9.8% (95% CI, 4.3-17.1%) of twins managed expectantly and in 13.1% (95% CI, 9.2-17.6%), 12.1% (95% CI, 7.7-17.3%) and 7.6% (95% CI, 1.3-18.5%) of those treated with laser surgery, IUT and SR, respectively. Severe neonatal morbidity affected 27.3% (95% CI, 13.6-43.6%) of twins in the expectant-management group, 28.7% (95% CI, 22.7-35.1%) of those in the laser-surgery group, 38.2% (95% CI, 18.3-60.5%) of those in the IUT group and 23.3% (95% CI, 10.5-39.2%) of those in the SR group. PTB complicated 80.4% (95% CI, 59.8-94.8%), 73.4% (95% CI, 48.1-92.3%), 100% (95% CI, 76.5-100%) and 100% (95% CI, 39.8-100%) of pregnancies after expectant management, laser surgery, IUT and SR, respectively.

CONCLUSIONS

The present meta-analysis provides pooled estimates of the risks of perinatal mortality, neonatal morbidity and PTB in twin pregnancies complicated by TAPS, stratified by the type of TAPS and the management option adopted. Although a direct comparison could not be performed, the results from this systematic review suggest that spontaneous TAPS may have a better prognosis than postlaser TAPS. No differences in terms of mortality and morbidity were observed when comparing different management options for TAPS, although these findings should be interpreted with caution in view of the limitations of the included studies. Individualized prenatal management, taking into account the severity of TAPS and gestational age, is currently the recommended strategy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.