Influence of indications on perinatal outcomes after radio frequency ablation in complicated monochorionic pregnancies: a retrospective cohort study

Background

Radiofrequency ablation (RFA) is recommended to prevent potential neurological injury or intrauterine foetal death (IUFD) of the co-twin(s) in complicated monochorionic (MC) pregnancies. However, the impacts of various indications on the pregnancy outcome following RFA remain unclear. This study aimed to determine how the indications influence the perinatal outcomes in complicated MC pregnancies undergoing radiofrequency ablation.

Methods

This was a retrospective cohort study performed in a single centre. All consecutive MC pregnancies treated with RFA between July 2011 and July 2019 were included. The adverse perinatal outcomes and the survival rate were analysed based on various indications. The continuous variables with and without normal distribution were compared between the groups using Student’s t-test and Mann–Whitney U test, respectively, and for categorical variables, Chi-square and Fisher’s exact tests were used. P < 0.05 indicated a significant difference.

Results

We performed 272 RFA procedures in 268 complicated MC pregnancies, including 60 selective intrauterine growth restriction (sIUGR), 64 twin–twin transfusion syndrome (TTTS), 12 twin reversed arterial perfusion sequence (TRAPs), 66 foetal anomaly and 66 elective foetal reduction (EFR) cases. The overall survival rate of the co-twin was 201/272 (73.9%). The overall technical successful rate was determined at 201/263 (76.7%). The IUFD rate in the co-twin was 20/272 (7.4%). The TTTS group had recorded the lowest survival rate (37/64, 57. 8%), and the survival rate was significantly correlated with Quintero stages (P = 0.029). Moreover, the sIUGR III subgroup had a lower survival rate compared with sIUGR II (55.6%, versus 84.3%). The subgroup of foetal anomaly of gastroschisis or exomphalos had the highest IUFD rate (4/10, 40%), followed by sIUGR III (2/9, 22.2%) and dichorionic triamniotic (DCTA) subgroup (8/46, 17.9%). In EFR group, eight IUFD cases were all coming from the DCTA subgroup and received RFA before 17 weeks.

Conclusions

The perinatal outcome of RFA was correlated with the indications, with the lowest survival rate in TTTS IV and the highest IUFD incidence in abdominal wall defect followed by sIUGR III. Elective RFA after 17 weeks may prevent IUFD in DCTA pregnancies.

Risk Factors for Co-Twin Fetal Demise following Radiofrequency Ablation in Multifetal Monochorionic Gestations

BACKGROUND

Umbilical cord occlusion via radiofrequency ablation (RFA) is utilized to maximize outcomes of the co-twin in complicated multifetal monochorionic (MC) gestations. However, post-procedure co-twin fetal demise is of concern.

OBJECTIVE

The aim of this study was to determine risk factors for co-twin fetal demise following RFA.

METHODS

This is a retrospective study of MC multiples that underwent RFA. Indications for RFA included twin reversed arterial perfusion (TRAP) sequence, selective fetal growth restriction (sFGR) type II, discordant lethal anomalies, and twin-twin transfusion syndrome (TTTS) with proximate placental cord insertion sites. The primary outcome was co-twin fetal demise. Bivariate analyses and multiple logistic regression modeling of identified risk factors were conducted.

RESULTS

Of 36 patients studied, surgical indications were: TRAP (n = 15, 41.7%), sFGR (n = 10, 27.8%), discordant anomalies (n = 9, 25.0%), and TTTS (n = 2, 5.6%). Nine patients (25.0%) experienced a co-twin fetal demise. In multiple logistic regression analysis, fetal growth restriction (FGR) of one co-twin was associated with increased risk of co-twin fetal demise (OR = 10.85, 95% CI 1.03-114.48, p = 0.0474) and a preoperative diagnosis of TRAP was protective against fetal demise (OR = 0.06, 95% CI 0.00-0.84, p = 0.0368).

CONCLUSION

Co-twin FGR was associated with an increased risk of post-RFA demise. When compared to other indications, patients with TRAP sequence were less likely to have a co-twin demise.

Short-Term Flow Changes in Monochorionic Survivor Twins after Ultrasound-Guided Umbilical Cord Occlusion

OBJECTIVE

To determine hemodynamic changes by Doppler ultrasound of the living fetus during 24 h after umbilical cord occlusion (UCO) in monochorionic diamniotic (MCDA) twin pregnancies.

METHOD

We conducted a prospective observational study on fetuses undergoing UCO from 2015 to 2017. Doppler parameters peak systolic velocity (PSV) and umbilical pulsatility index (PI) were obtained in the middle cerebral artery (MCA), umbilical artery (UA) and ductus venosus (DV) before and right after UCO, and at 1, 3, 6, 12, and 24 h after. We used multiple of the median (MoM) to adjust for gestational age. Spaghetti plots visualized flow changes over time. Mixed model adjusting for paired longitudinal data compared the values at different time points.

RESULTS

A total of 16 women were included. MCA-PSV dropped within the first hour after surgery from 0.91 to 0.82 MoM (p = 0.08). MCA-PI and UA-PI increased in the first hour from 0.75 to 0.91 MoM (p = 0.02) and 0.94 to 0.98 MoM (p = 0.22), respectively. The DV-PIV increased to 1.14 MoM 3 h after surgery (p = 0.07). The spaghetti plots illustrated the small changes within the first hours and showed a stabilization of flow measurements near initial values 24 h after UCO.

CONCLUSION

Within the first hours after UCO the circulation of the survivor twin undergoes small hemodynamic changes.

Long-Term Neurodevelopmental Outcome of Monochorionic Twins after Laser Therapy or Umbilical Cord Occlusion for Twin-Twin Transfusion Syndrome

INTRODUCTION

We sought to assess the incidence of severe neurodevelopmental impairment (NDI) in monochorionic twins treated for twin-twin transfusion syndrome (TTTS) and compare it to the incidence in uncomplicated monochorionic twins.

MATERIAL AND METHODS

We included TTTS pregnancies treated by fetoscopic selective laser coagulation (FSLC) or umbilical cord occlusion (UCO) in 2004-2015. Primary outcome was severe NDI defined as cerebral palsy, bilateral blindness or bilateral deafness (ICD-10 diagnoses), and severe cognitive and/or motor delay (assessed by the Ages and Stages Questionnaires [ASQ]).

RESULTS

A total of 124 children after TTTS and 98 controls were followed up at 25 months of age (SD 11.4). Severe NDI was found in 8.9% of the TTTS children (10.5% [9/86] after FSLC; 5.3% [2/38] after UCO) compared to 3.1% in the control group (p = 0.10). The odds ratio for severe NDI was 1.8 in cases versus controls (p = 0.37). The total ASQ score was significantly lower in the TTTS group than in controls (p = 0.03) after FSLC (p = 0.03) and after UCO (p = 0.14).

DISCUSSION

Children after TTTS appear to have a higher risk of severe NDI and score significantly lower on the ASQ compared to monochorionic twins from uncomplicated pregnancies.

Selective intrauterine growth restriction in monochorionic diamniotic twin pregnancies

Selective intrauterine growth restriction (sIUGR) affects 10-15% of all monochorionic pregnancies. Early severe forms are associated with intrauterine demise or neurological adverse outcome for both twins. The characteristics of umbilical artery (UA) Doppler in the IUGR fetus determine three clinical types: (I) normal UA Doppler and associated with good prognosis; (II) persistently absent/reverse UA end-diastolic flow and associated with early deterioration of the IUGR twin and very preterm delivery; (III) intermittently absent/reverse end-diastolic flow in the UA, and associated with unexpected fetal demise or neurological injury in one or both twins. Types II and III pose important challenges for management. Placental laser or cord occlusions do not seem to increase survival, but they might improve the outcomes of the larger twin. The use of an algorithm with severity criteria may help in counseling and planning management.

Umbilical Cord Occlusion via Laser Coagulation in Monochorionic Multifetal Gestations before and after 20 Weeks of Gestation

INTRODUCTION

Umbilical cord occlusion (UCO) utilizing laser photocoagulation is often not considered an option for selective termination after 20 weeks of gestation due to reported limitations of the procedure because of umbilical cord size. We compared outcomes after laser umbilical cord occlusion (L-UCO) before and after 20 weeks of gestation.

MATERIALS AND METHODS

We examined all patients with monochorionic- diamniotic twins and higher-order multiples (monoamniotic excluded) that underwent L-UCO at our facility between 2006 and 2014. Statistical analysis was performed using Fisher's exact and Kruskal-Wallis tests as appropriate.

RESULTS

Of 43 L-UCO cases, 11 cases (25.6%) had a discordant anomaly, and 32 cases (74.4%) had twin reversed arterial perfusion (TRAP) sequence. We achieved complete vascular occlusion in 100% (43/43) of cases of attempted L-UCO. There were 22 cases (51.2%) with gestational age ≤20 weeks, and 21 cases (48.8%) with gestational age >20 weeks. Perioperative patient characteristics and outcomes did not differ between the two groups. Survival rates were 90.9% (20/22) and 100% (21/21) at ≤20 weeks of gestation and >20 weeks of gestation, respectively.

DISCUSSION

The results of this study suggest that L-UCO is a reasonable surgical modality for patients prior to and beyond 20 weeks of gestation.