Pregnancy outcomes following early fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome at 16 weeks' gestation

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

OBJECTIVE

There are conflicting data on whether fetoscopic laser photocoagulation (FLP) of placental anastomoses for the treatment of twin-to-twin transfusion syndrome (TTTS) is associated with lower rates of overall survival. The objective of this study was to characterize twin survival and associated morbidity according to the gestational age at which FLP was performed.

METHODS

This was a secondary analysis of data collected prospectively on patients with a monochorionic diamniotic (MCDA) twin pregnancy who underwent FLP for TTTS at two centers between January 2011 and December 2022. Patients were divided into six groups according to gestational age at the time of FLP: < 18 weeks, 18 + 0 to 19 + 6 weeks, 20 + 0 to 21 + 6 weeks, 22 + 0 to 23 + 6 weeks, 24 + 0 to 25 + 6 weeks and ≥ 26 weeks. Demographic characteristics, sonographic characteristics of TTTS and operative characteristics were compared across the gestational age epochs. Outcomes, including overall survival, preterm delivery (PTD), 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-Meier curves were constructed to compare the interval from PPROM to delivery between gestational age epochs.

RESULTS

There were 768 patients that met the inclusion criteria. The rate of dual twin survival was 61.3% for cases in which FLP was performed before 18 weeks, compared with 78.0%-86.7% when FLP was performed at ≥ 18 weeks' gestation. This appears to be driven by an increased rate of donor IUFD following FLP performed before 18 weeks (28.0%) compared with ≥ 18 weeks (9.3-14.1%). Rates of recipient IUFD and NND and donor NND were similar regardless of gestational age at FLP. The rate of PPROM was higher for FLP conducted at earlier gestational ages, ranging from 45.6% for FLP before 18 weeks to 11.9% for FLP performed at 24 + 0 to 25 + 6 weeks' gestation. However, gestational age at delivery was similar across gestational age epochs, with a median of 31.7 weeks. On multivariate analysis, donor twin loss was associated with FLP before 18 weeks, even after adjusting for selective fetal growth restriction, Quintero stage and other covariates. PPROM and PTD were also associated with FLP performed before 18 weeks after adjusting for cervical length, placental location, trocar size, laser energy and amnioinfusion.

CONCLUSIONS

FLP performed at earlier gestational ages is associated with lower overall survival, which is driven by the increased risk of donor IUFD, as opposed to differences in the rate of PPROM or PTD. Parental counseling regarding twin survival should account for the gestational age at which patients present with TTTS. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Perinatal outcomes following fetoscopic laser surgery for early twin-to-twin transfusion syndrome: Systematic review and meta-analysis

INTRODUCTION

Our objective was to investigate outcomes in twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser surgery (FLS) at <18 weeks vs ≥18 weeks, and to conduct subgroup analysis of TTTS with FLS at <16 weeks vs 16-18 weeks.

MATERIAL AND METHODS

PubMed, Scopus and Web of Science were searched systematically from inception until May 2023. Primary outcome was survival, and secondary outcomes included preterm premature rupture of membranes (PPROM), preterm birth and gestational age (GA) at delivery.

RESULTS

Nine studies encompassing 1691 TTTS pregnancies were included. TTTS stage III was significantly more common in TTTS pregnancies treated with FLS at <18 weeks (odds ratio [OR] 2.84, 95% confidence interval [CI] 1.24-6.54), and procedure duration was shorter at <18 weeks (MD -5.27 minutes, 95% CI -9.19 to -1.34). GA at delivery was significantly earlier in TTTS pregnancies treated with FLS at <18 weeks (MD -3.12 weeks, 95% CI -6.11 to -0.13). There were no significant differences in outcomes, including PPROM, PPROM at <7 days post-FLS, preterm birth at <28 and <32 weeks, delivery at <7 days post-FLS, and survival outcomes, including fetal demise, live birth and neonatal survival. Similarly, TTTS stage III was more common in TTTS with FLS at <16 weeks than at 16-18 weeks (OR 2.95, 95% CI 1.62-5.35), with no significant differences in the aforementioned outcomes.

CONCLUSIONS

In early TTTS treated with FLS, outcomes were comparable between those treated at <18 weeks compared with ≥18 weeks except for GA at delivery, which was 3 weeks earlier. In the subset treated at <16 weeks vs 16-18 weeks, the procedure was feasible without an increased risk of very early preterm birth or perinatal mortality.

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.