Interstitial laser therapy for fetal reduction in monochorionic multiple pregnancy: loss rate and association with aplasia cutis congenita

A systematic review of early intrauterine intervention at 12 + 0 to 16 + 6 weeks in twin reversed arterial perfusion sequence

There is some evidence that in twin reversed arterial perfusion sequence, intervention at early gestational age could prevent a spontaneous death of the pump twin, achieving a better global survival.

OBJECTIVE

To review the perinatal outcomes of early intervention in pregnancies complicated by twin reversed arterial perfusion (TRAP) sequence.

STUDY DESIGN

A comprehensive search from inception to December 2022 was conducted on databases including MEDLINE, EMBASE, Cochrane Library and LILACS. All studies that reported intervention in twin or triplet pregnancy complicated with TRAP sequence at 12 + 0 to 16 + 6 weeks of gestation were eligible. A descriptive and bivariate analysis was performed.

RESULTS

Out of the 222 full-text articles, 44 studies reporting 108 cases of early intervention in TRAP sequence were included. A successful procedure was achieved in 105 (95.5 %) interventions: 89 (94.7 %) among twin pregnancies and 16(100 %) among triplet pregnancies. An overall livebirth rate was achieved in 75 patients (70.8 %): intrafetal laser group 55 (73.3 %), radiofrequency 10 (76.9 %) and endoscopic laser 3 (75.0 %). The median gestational age at delivery was 38 + 0 (37 + 4 - 39 + 4) weeks. The median treatment-delivery interval was 23 + 2 (IQR, 21 + 0-25 + 6) weeks. The most frequent adverse outcomes reported were preterm labor in 7 (13.7 %) patients. There were no severe adverse maternal outcomes.

CONCLUSION

Early intervention with intrafetal laser and radiofrequency in TRAP sequence achieves a livebirth rate of the pump twin of about 75 %.

Clinical value of high-intensity focused ultrasound in fetal reduction

Complex twin reduction surgery is a common but challenging procedure that aims to reduce the risks and complications of multiple pregnancies. The search for safer and more effective methods has led to the development of high-intensity focused ultrasound (HIFU) technology in the field of fetal reduction. This technology utilizes high-energy sound waves to focus precisely on specific areas, achieving non-invasive therapeutic effects. This paper discusses the principles and features of HIFU technology, as well as its application in complex twin reduction surgery. The paper aims to elucidate the important role of this technology in improving surgical outcomes and reducing risks, explore the current limitations of the modality, and propose directions for future development. Through these investigations, it is hoped to improve overall understanding of HIFU, and thereby promote the application of this technology in the field of fetal reduction.

Clinical outcomes of fetal selective reduction in dichorionic triplet pregnancies

BACKGROUND

It is recommended to reduce triplet pregnancy containing monochorionic (MC) twins to singleton. Given that some couples with infertility are eager to retain twins, better strategy is needed to avoid obstetrical risks and satisfy their strong wish. This retrospective observational study aimed to investigate the outcomes of triplet pregnancy reduction.

METHODS

Subjects with triplet pregnancies who underwent selective reduction between 2016 and 2019 at our hospital were enrolled. A total of 66 subjects with dichorionic triplet (DCT) with MC twins and an MC singleton were divided into two groups: group A (N = 38), reduced to dichorionic diamniotic (DCDA) twins; group B (N = 28), reduced to MC diamniotic (MCDA) twins. Obstetrical and perinatal outcomes were compared between groups.

RESULTS

Group A had significantly lower rates of early miscarriage (0% vs 14.3%, p = 0.028), cesarean section (81.6% vs 100%, p = 0.041), and late premature delivery (21.1% vs 45.4%, p = 0.047) than group B. Significantly higher rates of full-term delivery (71% vs 36.4%, p = 0.009) and take-home baby (100% vs 78.6%, p = 0.004), and higher gestational age at delivery (median: 38 [36.9, 39.0] vs 35.8 [34.4, 37.0] weeks, p < 0.001), total neonatal weight (2899.7 ± 647.6 vs 2354.4 ± 651.8 g, p < 0.001), weight of twins (2550 vs 2350 g, p = 0.039), and weight of larger neonate in twins (2790 vs 2500 g, p = 0.045) were observed in group A compared to group B.

CONCLUSION

DCT reduced to DCDA twins confers better pregnancy outcomes than into MCDA twins. This might benefit for triplet pregnancy subjects who strongly want to retain fraternal twins.

[Monochorionic biamniotic twin pregnancies outcomes in Reunion Island with indication of in utero transfert]

OBJECTIVE

Complicated monochorionic biamniotic (MCBA) twin pregnancies may require treatment with fetoscopic laser photocoagulation, in case of Twin Oligo-Polyhydramnios Sequence or need of a selective termination of pregnancy. Patients requiring these treatments would need medical transfer to Metropolitan France because these are unavailable in Réunion Island. We evaluated the outcomes of MCBA pregnancies in Reunion Island with indications for fetoscopy, with a view to discussing the interest of training doctors on the Reunion Island, to practice fetoscopy on site.

MATERIALS AND METHODS

Retrospective hospital study running from 2015 to 2018. We included all MCBA pregnancies between 15 and 25 weeks of gestation, with indications for in utero transfer. Our objective was to examine whether and why they were transferred and pregnancy outcomes.

RESULTS

Of the 23 patients, 17 (73.9%) benefited from sanitary transfers. The survival rate of the fetuses in 15 pregnancies with Twin Oligo-Polyhydramnios Sequence (TOPS) was 73.3% for one twin and 53.3% for both twins. For the eight cases of Selective Termination of the pregnancy (ST), the survival rate of the twin was better with a transfer (n=5/6, 83.3%) than without a transfer (n=1/2 or 50%). The rate of premature rupture of the membranes after sanitary transfer among patients with TOPS was 63.6%.

CONCLUSION

The sanitary transfer allows the management in expert center of complicated MCBA twin pregnancies, but is not always feasible and is accompanied by a high rate of premature ruptures of membranes.

Timing of intra-fetal laser therapy for twin reversed arterial perfusion (TRAP) sequence: Retrospective series and systematic review and meta-analysis

OBJECTIVE

To estimate the neonatal survival rate after intra-fetal laser (IFL) treatment for twin reversed arterial perfusion (TRAP) sequence, and to investigate the effect of gestational age at the time of procedure.

METHODS

Retrospective cohort study of TRAP sequences followed at our institution from 2013-2020. Systematic review and meta-analysis of the neonatal survival rate after IFL was conducted. Both diamniotic and monoamniotic monochorionic pregnancies were included. A subgroup analysis to compare outcomes according to gestational age at procedure (<16⁺⁰ weeks or ≥16⁺⁰ weeks) was planned.

RESULTS

Thirteen pregnancies were followed at our center and seven were treated with IFL: the survival rate was 57%. Ten studies published between 2008 and 2020 for a total of 156 cases were included in the meta-analysis. The overall neonatal survival after IFL was 79% (95% CI 0.72-0.86, I² 22%). A random-effects model comparing neonatal survival for IFL performed <16⁺⁰ weeks versus ≥16⁺⁰ weeks showed no significant difference between the two groups (OR = 0.93; 95% CI 0.37-2.33).

CONCLUSION

IFL is a safe and minimally invasive technique for the treatment of TRAP sequence, with a survival rate of 79%. Gestational age at treatment (before or after 16 weeks) does not seem to affect neonatal survival rate.

Amyoplasia in monochorionic monozygotic pregnancy following interstitial laser

Amyoplasia is a specific form of arthrogryposis, without any genetic cause. Six to ten percent of amyoplasia cases are one of the monozygotic twins, with the other twin being normal. Failure of maturation of anterior horn cells (AHCs) due to ischemic injury has been postulated as the primary pathological change, leading to arrest in the development of muscle fibers supplied by the affected AHCs with the typical limb positioning seen in amyoplasia. Twin-to-twin transfusion syndrome (TTTS) is an important risk factor for ischemic injury in monozygotic twin pregnancies. We present a case of monochorionic diamniotic twin pregnancy with features of TTTS at 12 weeks who underwent interstitial laser followed by the development of lower limb akinesia in the surviving fetus. Possible causes of amyoplasia are discussed.

Selective termination of the fetus in multiple pregnancies using ultrasound-guided radiofrequency ablation

Background

To evaluate the perinatal outcomes in women with selective termination using ultrasound-guided radiofrequency ablation (RFA).

Methods

Complicated monochorionic (MC) twin pregnancies and multiple pregnancies with an indication for selective termination by ultrasound-guided coagulation of the umbilical cord with RFA under local anesthesia between July 2013 and Jan 2020 were reviewed. We analyzed the indications, gestational age at the time of the procedure, cycles of RFA, duration of the procedure, and perinatal outcome.

Results

Three hundred and thirteen patients were treated during this period. Seven of whom were lost of follow-up. The remaining 306 cases, including 266 pairs of monochorionic diamniotic (MCDA) twins (86.93%), two pairs of monoamniotic twins (0.65%), 30 dichorionic triamniotic (DCTA) triplets (1%), and three monochorionic triamniotic (MCTA) triplets (0.98%), were analyzed. Indications included twin-to-twin transfusion syndrome (TTTS) (n = 91), selective fetal growth restriction (sFGR) (n = 83), severe discordant structural malformation (n = 78), multifetal pregnancy reduction (MFPR) (n = 78), twin reverse arterial perfusion sequence (TRAPS) (n = 19), and twin anemia-polycythemia sequence (TAPS) (n = 3). Upon comparison of RFA performed before and after 20 weeks, the co-twin loss rate (20.9% vs. 21.5%), the incidence of preterm premature rupture of membranes (PPROM) within 24 h (1.5% vs. 1.2%), and the median gestational age at delivery [35.93 (28–38) weeks vs. 36 (28.54–38.14) weeks] were similar (p > 0.05).

Conclusions

RFA is a reasonable option when indicated in multiple pregnancies and complicated monochorionic pregnancies. In our experience, the overall survival rate was 78.76% with RFA in selective feticide, and early treatment increases the likelihood of survival for the remaining fetus because the fetal loss rate is similar before and after 20 weeks.

Perinatal outcomes after selective feticide via umbilical cord occlusion in complicated monochorionic pregnancies: A systematic review and meta-analysis

OBJECTIVE

We aimed to compare perinatal outcomes between umbilical cord occlusion techniques in monochorionic pregnancies, including umbilical cord ligation, fetoscopic laser coagulation, interstitial laser coagulation, bipolar cord occlusion, radiofrequency ablation, and microwave ablation.

METHODS

This study was registered with PROSPERO (CRD42020158861). PubMed, Web of Science, Cochrane Library, and Embase were searched for studies published up to May 2020. The DerSimonian-Laird random-effects model was used for the meta-analysis. Subgroup analyses were performed to compare the outcomes among the six techniques. Meta-regression was used to adjust for confounders.

RESULTS

Thirty-four studies with 1646 participants were included. The overall survival was 76.5% after umbilical cord ligation, 78.8% after fetoscopic laser coagulation, 60.3% after interstitial laser coagulation, 79.2% after bipolar cord occlusion, 77.5% after radiofrequency ablation, and 75.0% after microwave ablation. Subgroup comparison showed the rates of overall survival and preterm premature rupture of membranes were not significant different among six techniques. However, rates of fetal loss, premature birth, live birth, and neonatal death differed significantly among the six groups.

CONCLUSIONS

The choice of umbilical cord occlusion techniques will affect perinatal outcomes. We suggested that the choice of umbilical cord occlusion techniques should fully consider these differences among techniques.

Aplasia cutis congenita as a consequence of fetal reduction in a triplet pregnancy

Background

Aplasia cutis congenita (ACC) is a rare skin disorder characterized by a localized absence of skin at birth. It has been linked to both assisted reproductive technology (ART) and feto-reduction procedures. Group V ACC presents with a distinct, symmetrical distribution pattern. It is thought to result from an insult to the fetus after concomitant twin demise and is almost exclusively reported in monochorionic gestations.

Case presentation

We report a rare case of Group V ACC in a dichorionic, triamniotic (di-Tri) triplet in-vitro fertilization (IVF) pregnancy subsequent to feto-reduction. The lesions were managed conservatively.

Conclusion

ACC in multi-fetal pregnancies is a rare, but widely described complication. With increased incidence of ART-associated pregnancies and the use of feto-reduction for multiple pregnancies, this may become a more common phenomenon. Neonatologists and obstetricians should be aware of this complication and counsel their feto-reduction patients on the risks. This case is interesting because, to the best of our knowledge, there have been only nine reported cases of Group V ACC in triplet or higher order gestations.

Perinatal outcomes of monochorionic diamniotic triplet pregnancies: a case series

Background

Triplet pregnancies are associated with higher fetal morbidity and mortality rates as well as life-threatening maternal complications. Monochorionic diamniotic (MCDA) triplet pregnancies are very rare compared to other types of triplet pregnancies.

Case presentation

We report three cases of MCDA triplet pregnancies between January 2012 and December 2017. Two of these MCDA triplet pregnancies received regular and intensive prenatal care, were diagnosed by ultrasonography during the first trimester or early second trimester, and had good perinatal outcomes. The case with irregular perinatal care had poor outcomes, and the MCDA triplet pregnancy was diagnosed intrapartum.

Conclusions

The possibility of continuing an MCDA triplet pregnancy should be recognized. Early diagnosis, regular antenatal care, close prenatal monitoring, and sufficient communication are recommended to obtain better perinatal outcomes in MCDA triplet pregnancies.

Congenital Laser-Induced Burns: A Potential Complication after Laser Photocoagulation in Monochorionic Twin Pregnancy

Background: Fetoscopic laser photocoagulation can directly injure fetal skin and may at birth resemble aplasia cutis congenita (ACC). Case report: A twin monochorionic pregnancy was complicated by twin-to-twin transfusion syndrome requiring in utero laser photocoagulation, resulting in the death of one twin. After birth, the viable baby presented skin lesions in both legs that were congruent with laser-induced burns. Conclusions: Laser-induced burns present as asymmetric superficial non-necrotic or ulcerated lesions, with a geographic outline, which turn into scars with no retraction or contractures and no changes in pain perception or motor limitations over time. ACC lesions are bilateral and symmetric, with a regular outline, an ulcerated or necrotic appearance, a higher degree of skin involvement affecting all skin layers and, over time, they turn into scars with retraction and contractures. These differential features may help clinicians in a challenging approach to the diagnosis of congenital skin defects.

TRAP Sequence in Monochorionic/Monoamniotic (MC/MA) Discordant Twins: Two Cases Treated with Fetoscopic Laser Surgery

INTRODUCTION

Ablation of the acardiac twin umbilical cord in the TRAP protects the normal donor twin.

MATERIALS AND METHODS

Two case descriptions, one of interstitial laser photocoagulation and one of laser umbilical cord occlusion (L-UCO) of the acardiac twin in monochorionic monoamniotic pregnancies are reported.

RESULTS

L-UCO in two pregnancies with TRAP syndrome in the second trimester resulted in intrauterine fetal death in both cases after 1 month. Case 1 had no detectable cause of fetal death. Case 2 had rupture of the amniotic sac causing anhydramnios and acute chorioamnionitis. A groove on the umbilical cord of the normal twin indicated a cord stricture due to cord entanglement.

CONCLUSION

Our experience confirms that the best timing and optimal treatment of MC/MA twins complicated by TRAP sequence still remains a controversial clinical issue. Cord entanglement may continue be a potential clinical risk factor for adverse perinatal outcome even after ablation therapy.

Aplasia cutis congenita as a result of interstitial laser therapy for fetal reduction in monochorionic twins: Conservative approach and outcome

•

Laser therapy for fetal reduction could be associate with Aplasia Cutis Congenita.

•

Despite of size of lesion conservative treatment could be an effective option.

•

Extreme prematurity did not affected degree of spontaneous epithelization.

•

Patient was followed up to 5 years and no complications were detected.

Monochorionic (MC) twin pregnancies are known to carry a high risk of twin-to-twin transfusion syndrome (TTTS) that could lead to miscarriage and perinatal death. Demise of one fetus is frequently associated with co-fetal death. Fetal reduction by interstitial laser therapy is an effective procedure to prevent this outcome, but it may be associated with significant risks for both mother and fetus. Aplasia Cutis Congenita (ACC) may occur in up to 8% cases of fetal reduction by laser therapy. We report ACC in a preterm infant, a survivor of interstitial laser therapy for fetal reduction in MC pregnancy. Despite of massive skin lesions we were able to manage this case conservatively. Follow-up at 5 years of age revealed minimal scarring and no motor function limitations.

First-trimester intervention in twin reversed arterial perfusion sequence: does size matter?

OBJECTIVE

To evaluate the outcome of first-trimester intervention (12 + 0 to 14 + 0 weeks of gestation) in pregnancies complicated by twin reversed arterial perfusion (TRAP) sequence.

METHODS

All monochorionic diamniotic twin pregnancies diagnosed with TRAP sequence that underwent intrafetal laser ablation (IFL) of the feeding vessels before 14 + 0 weeks of gestation at the University of Bonn between 2010 and 2015 were analyzed retrospectively for intrauterine course and outcome.

RESULTS

In the study period, 12 pregnancies with TRAP sequence were treated by IFL. Median gestational age at intervention was 13.2 (interquartile range (IQR), 12.6-13.6) weeks. In all cases, one intervention sufficed to disrupt the perfusion of the TRAP twin. There was no case of miscarriage, preterm prelabor rupture of membranes or hemorrhage. In five (41.7%) pregnancies, intrauterine death of the pump twin occurred at a median of 72.0 (IQR, 54.0-90.0; range, 48-96) h after intervention. The remaining seven pregnancies continued uneventfully resulting in birth of a healthy infant at term. A comparison of survivors and non-survivors identified a significant difference in median discordance between crown-rump length (CRL) of the pump twin and upper pole-rump length (URL) of the TRAP twin ((CRL - URL)/CRL ratio, 0.56 vs 0.31; P < 0.05 and URL/CRL ratio, 0.44 vs 0.68; P < 0.05). Survivors were treated at a significantly later gestational age than were non-survivors (median, 13.4 (IQR, 12.9-14.1) vs 12.6 (IQR, 12.5-13.1); P < 0.05). However, none of these parameters independently predicted survival.

CONCLUSIONS

Although technically feasible, IFL performed in the first trimester for TRAP sequence is associated with a significant fetal loss rate. Gestational age at intervention, (CRL - URL)/CRL ratio and URL/CRL ratio are potential predictors of pregnancy outcome. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Intervention versus a conservative approach in the management of TRAP sequence: a systematic review

OBJECTIVE

In the management of twin reversed arterial perfusion (TRAP) sequence, we wished to (i) determine if intervention is better than a conservative approach and (ii) assess if any of the apparent adverse prognostic indicators could guide intervention.

METHODS

A systematic review was conducted between 1994 and 2014. Data extracted were inspected for heterogeneity. Overall rates and confidence intervals (CIs) for each prognostic factor were calculated. Where there were comparative data, the odds ratio (OR) was calculated.

RESULTS

Twenty-six studies were included in the review. When all cases were considered, intervention either by cord occlusion or by ablation conferred a better survival rate compared with conservative management (OR=2.22, 95% CI 1.23-4.01, heterogeneity I2=37%, P=0.008). This difference was greater in the presence of one or more poor prognostic features (OR=8.58, 95% CI 1.47-49.96, heterogeneity I2=0%, P=0.02). Survival was better using ablative techniques compared to cord occlusion (OR=9.84, 95% CI 1.56-62.00, heterogeneity I2=0%, P=0.01).

CONCLUSION

Intervention either by cord occlusion or by ablation confers a better survival rate compared to conservative management. This appears more compelling if there are one or more poor prognostic features. Ablative techniques are superior to cord occlusion. There were insufficient data to determine which poor prognostic features should guide management.

Long-term neurodevelopmental outcome after selective feticide in monochorionic pregnancies

OBJECTIVE

To assess the incidence of and risk factors for adverse long-term neurodevelopmental outcome in complicated monochorionic pregnancies treated with selective feticide at our centre between 2000 and 2011.

DESIGN

Observational cohort study.

SETTING

National referral centre for fetal therapy (Leiden University Medical Centre, the Netherlands).

POPULATION

Neurodevelopmental outcome was assessed in 74 long-term survivors.

METHODS

Children, at least 2 years of age, underwent an assessment of neurologic, motor and cognitive development using standardised psychometric tests and the parents completed a behavioural questionnaire.

MAIN OUTCOME MEASURES

A composite outcome termed neurodevelopmental impairment including cerebral palsy (GMFCS II-V), cognitive and/or motor test score of <70, bilateral blindness or bilateral deafness requiring amplification.

RESULTS

A total of 131 monochorionic pregnancies were treated with selective feticide at the Leiden University Medical Centre. Overall survival rate was 88/131 (67%). Long-term outcome was assessed in 74/88 (84%). Neurodevelopmental impairment was detected in 5/74 [6.8%, 95% confidence interval (CI), 1.1-12.5] of survivors. Overall adverse outcome, including perinatal mortality or neurodevelopmental impairment was 48/131 (36.6%). In multivariate analysis, parental educational level was associated with cognitive test scores (regression coefficient B 3.9, 95% CI 1.8-6.0). Behavioural problems were reported in 10/69 (14.5%).

CONCLUSIONS

Adverse long-term outcome in survivor twins of complicated monochorionic pregnancies treated with selective feticide appears to be more prevalent than in the general population. Cognitive test scores were associated with parental educational level.

TWEETABLE ABSTRACT

Neurodevelopmental impairment after selective feticide was detected in 5/74 (6.8%, 95% CI 1.1-12.5) of survivors.

A rare presentation of aplasia cutis congenita after feto-reduction in a trichorionic-triamniotic pregnancy

Aplasia cutis congenita (ACC) is rare skin disorder of newborns that has been linked to both assisted reproductive technology (ART) and feto-reduction procedures. ACC is characterized by well-demarcated lesions that are devoid of all skin layers. Group-V ACC presents with a distinctive and symmetrical distribution pattern. It is thought to result from an insult to the fetus after concomitant twin demise and is almost exclusively reported in monochorionic gestations.A 41-year-old female with an in vitro fertilization (IVF) assisted tri-chorionic gestation subsequently underwent selective feto-reduction of Fetus C. The patient delivered two pre-term neonates secondary to pre-eclampsia. The initial exam of Twin B showed extensive, well-demarcated, symmetrical areas devoid of any skin over the anterior and lateral trunk, extending up the lateral thoracic walls. Chest and abdominal viscera were visible through a thin fibrous membrane. The skin defects were managed conservatively with twice-daily dressings of Aquaphor, and Vaseline gauze. The areas of aplasia slowly contracted, though residual scarring was noted. After four weeks in the NICU, most of the areas were healed.ACC in multi-fetal pregnancies is a rare, but well-described complication. This is, to our knowledge, the first reported case in a tri-chorionic IVF gestation after feto-reduction. With increased incidence of ART-associated pregnancies and the use of feto-reduction for higher order gestations, this may become more common. Neonates often require specialized intensive care. Conservative management usually will suffice, although surgical grafting may be required. Physicians should be aware of this condition and counsel their feto-reduction patients of the risk.

Early vs late intervention in twin reversed arterial perfusion sequence

OBJECTIVE

To compare two different management approaches in prenatally diagnosed twin reversed arterial perfusion (TRAP) sequence.

METHODS

Retrospective analysis of all cases with TRAP sequence diagnosed in one center over a period of 10 years. Prior to 2010, all cases were managed expectantly until 19 weeks' gestation; thereafter, patients could choose either radiofrequency ablation (RFA) or expectant management (Group A). From 2010 onward all patients were offered interstitial laser at the time of diagnosis (12 weeks at the earliest) or expectant management (Group B).

RESULTS

Forty cases were included in the study. In Group A, 23 cases were diagnosed at a mean gestational age of 19.9 ± 6.3 weeks. Sixteen patients were managed expectantly (13 survivors, 81%), while six underwent RFA at the time of diagnosis and one later in pregnancy (six survivors, 86%). In Group B, 17 cases were diagnosed at a mean gestational age of 16.4 ± 4.7 weeks. Six patients chose expectant management (five survivors, 83%) and 11 had interstitial laser therapy at the time of diagnosis (eight survivors, 73%). The loss rate of the pump twin was not significantly different between Group A and Group B (three of 23 vs four of 17; P = 0.3). In Group B the rates of preterm premature rupture of membranes (PPROM) and delivery < 34 weeks were significantly lower, and gestational age at birth as well as birth weight were significantly higher than in Group A.

CONCLUSION

Despite the limitations resulting from its retrospective design, our study on management of TRAP sequence adds some evidence in favor of prophylactic intervention by intrafetal laser from 12 weeks onward.

Outcome following selective fetal reduction in monochorionic and dichorionic twin pregnancies discordant for structural, chromosomal and genetic disorders

BACKGROUND

To investigate the indications for offering selective fetal reduction in monochorionic (MC) and dichorionic (DC) twins and to correlate obstetric outcome with the antenatal procedure.

METHODS

All cases of MC and DC twins discordant for structural anomalies and for chromosomal/genetic abnormalities were included. Selective reductions performed for twin-to-twin transfusion syndrome or growth restriction were excluded. For DC twins, feticide was achieved using intracardiac injection of potassium chloride (KCl). For MC twins, bipolar cord occlusion (BCO), interstitial laser or radiofrequency ablation (RFA) was used.

RESULTS

There were 121 twin pregnancies discordant for structural and chromosomal abnormalities. Only 88 (56 were MC twins and 32 were DC twins) had selective reduction. For both MC and DC twins, the leading indication for selective reduction was structural anomalies with CNS malformations the most common. For all MC fetal reduction techniques, the overall pregnancy loss rate (<24 weeks) was 8.9% with RFA having the lowest procedure loss rate (7.7%). The preterm delivery rate was lowest with reduction in DC pregnancies. The live birth rates for MC twins were >87% and 100% for DC twins.

CONCLUSIONS

Selective reduction in MC pregnancies carries an increased procedure-related and preterm delivery rate compared with DC pregnancies. The main indication for selective reduction was structural malformations, with a predominance of CNS anomalies.

Intrafetal laser treatment for twin reversed arterial perfusion sequence: cohort study and meta-analysis

OBJECTIVES

To ascertain the outcome of twin reversed arterial perfusion (TRAP) sequence cases managed in our unit and to review systematically cases reported in the literature treated with intrafetal laser therapy.

METHODS

This was a retrospective cohort study of all TRAP sequence cases identified from 2000 to 2012 at our center. Pregnancy management and outcomes were ascertained from maternal and neonatal records. We also performed a meta-analysis of the literature on the use of intrafetal laser therapy for the treatment of TRAP. Adverse pregnancy outcome was defined as a composite of intrauterine death (IUD) and preterm birth before 37 weeks' gestation.

RESULTS

Twenty-three cases of TRAP were identified during the study period. Six were managed conservatively and 17 were treated with laser therapy. All cases managed conservatively were complicated by IUD at a median gestational age of 14 + 4 (interquartile range (IQR), 12 + 4 to 16 + 5) weeks. Among the treated cases, 14 (82%) delivered a healthy twin at a median gestational age of 37 + 1 (IQR, 34 + 0 to 38 + 3) weeks. Ten studies were reviewed in detail and the data were combined with those from the current study. The overall neonatal survival was 80%. Adverse pregnancy outcome was significantly lower when the treatment was performed before 16 weeks' gestation (19 vs 66%, P = 0.0025).

CONCLUSION

The study data demonstrate a high risk of spontaneous fetal demise in early pregnancy, lack of accurate prognostic markers and improved pregnancy outcome after laser therapy in cases of TRAP. In these cases we recommend elective treatment with intrafetal laser therapy at between 13 and 16 weeks' gestation.

Perinatal outcome after selective feticide in monochorionic twin pregnancies

OBJECTIVE

To evaluate the incidence and risk factors of adverse perinatal outcome in complicated monochorionic twin pregnancies treated with selective feticide.

METHODS

This was a retrospective analysis of prospectively collected data from a consecutive, national cohort. All monochorionic twin pregnancies treated with selective feticide at Leiden University Medical Center between June 2000 and November 2011 were included. Obstetric and neonatal data were recorded. The primary outcome measure was adverse perinatal outcome, including fetal or neonatal demise or severe neonatal morbidity.

RESULTS

Data on perinatal outcome were obtained in all cases (n = 131). Overall perinatal survival rate was 67.2% (88/131). Median gestational age at delivery was 34 (interquartile range, 23-38) weeks. Neonatal mortality and morbidity rate in liveborn children was 4.3% (4/92) and 12.0 % (11/92), respectively. Severe cerebral injury was detected in three children. The overall incidence of adverse perinatal outcome was 41.2% (54/131). Median gestational age at occurrence of preterm prelabor rupture of membranes (PPROM) was 19.0 weeks and 32.0 weeks in cases with and without adverse perinatal outcome, respectively (P = 0.017). Liveborn children with adverse perinatal outcome were born at a lower median gestational age (29.0 weeks) than were children without adverse perinatal outcome (38.0 weeks) (P < 0.001).

CONCLUSIONS

The risk of adverse perinatal outcome after selective feticide is high and associated with low gestational age at occurrence of PPROM and low gestational age at delivery. Long-term follow-up to assess neurodevelopmental outcome in survivors is required.

The vascular anastomoses in monochorionic twin pregnancies and their clinical consequences

Monochorionic twin pregnancies are at increased risk of adverse outcome because of the vascular anastomoses that connect the 2 fetal circulation systems. The shared circulation is responsible for some unique complications in monochorionic twins, such as the twin-to-twin transfusion syndrome, the twin anemia polycythemia sequence, the twin reversed arterial perfusion sequence, and monoamniotic twinning. Another consequence of the shared circulation is that the well-being of one twin critically depends on that of the other. In this review, we will describe the technique of placental injection. Further, we will discuss the role of the vascular anastomoses in each of the complications described above and provide an update on their management.

Neonatal morbidity in twin-twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Management in TTTS is a major challenge for obstetricians and neonatologists. Twins which are often born prematurely and may suffer from typical conditions associated with prematurity. In addition, surviving twins with TTTS are at increased risk for other complications including neurological, cardiovascular, renal and hematologic morbidity. Rare complications such as hypoxic-ischemic lesions to limbs or intestines and amniotic band syndrome have also been reported in TTTS survivors. This review focuses on the neonatal and pediatric mortality and morbidity in TTTS survivors, with special emphasis on the long-term neurodevelopmental outcome.

Selective reduction and termination of multiple pregnancies

The substantial increase in high order multiple pregnancies in the last two decades as a result of assisted reproductive techniques has necessitated the development of multifetal pregnancy reduction as a management tool to decrease fetal number and improve perinatal survival. The evidence in favour of reduction in pregnancies with more than four fetuses to twins is undisputed. Despite the recent improvements in expectant management of triplets with reasonable perinatal outcomes, the evidence suggests that reduction to twins significantly reduces the risk of preterm delivery without an increase in miscarriage rates. Recent advances in vascular-occlusive techniques have allowed the possibility of selective termination in monochorionic pregnancies in the presence of discordant anomalies or indeed multifetal reduction in non-trichorionic triplets, with radiofrequency ablation and cord occlusion appearing to be the most successful. However, the techniques vary in complexity and complication rates, which increase with gestation. Hence the need to refer these pregnancies early to specialist centres.

Specific complications of monochorionic twin pregnancies: twin-twin transfusion syndrome and twin reversed arterial perfusion sequence

Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins. This unequal placental sharing can cause complications including twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence (TAPS), selective intrauterine growth restriction or twin reversed arterial perfusion sequence (TRAP). Monochorionicity also makes the management of these specific complications as well as that of a severe malformation in one twin hazardous since the spontaneous death of one twin exposes the co-twin to a risk of exsanguination into the dead twin and its placenta. The latter is responsible for the death of the co-twin in up to 20% of the cases and in ischemic sequelae in about the same proportions in the survivors. Although the symptoms of all these complications are very different, the keystone of their management comes down to either surgical destruction of the inter-twin anastomoses on the chorionic plate when aiming at dual survival or selective and permanent occlusion of the cord of a severely affected twin aiming at protecting the normal co-twin. This can be best achieved by fetoscopic selective laser coagulation and bipolar forceps cord coagulation respectively.

The outcome of twin reversed arterial perfusion sequence diagnosed in the first trimester

OBJECTIVE

The aim of this study was to document the mortality of twin reversed arterial perfusion (TRAP) sequence from the first trimester to planned intervention at 16-18 weeks.

STUDY DESIGN

A retrospective review was performed of the outcome of monochorionic twin pregnancies diagnosed with twin reversed arterial perfusion sequence in the first trimester.

RESULTS

Twenty-six pregnancies were diagnosed with twin reversed arterial perfusion sequence in the first trimester: 2 opted for termination of pregnancy and 24 opted for prophylactic intervention to arrest the reversed flow, which was planned at 16-18 weeks. In 8 of 24 (33%) pregnancies, spontaneous death of the pump twin occurred between diagnosis and planned intervention. In 5 of 24 (21%), there was a spontaneous arrest of flow; whereas, in 11 (46%) there was persistent flow toward the acardiac twin at 16-18 weeks.

CONCLUSION

Twin reversed arterial perfusion carries a high mortality between the first and early second trimester.