Atypical twin-to-twin transfusion syndrome: prevalence in a population undergoing fetoscopic laser ablation of communicating placental vessels

Atypical twin-to-twin transfusion syndrome case managed in a single centre in Indonesia with fetoscopic laser photocoagulation and amniopatch: 'Case Report'

Introduction and importance

The diagnostic criteria for Quintero staging in twin-to-twin transfusion syndrome (TTTS) are not applicable in all cases of TTTS, such as those in which the symptoms overlap with other monochorionic twin complications such as selective intrauterine growth restriction (sIUGR).

Case presentation

A 25-year-old woman, G1P0A0, at 22-24 weeks' gestational age was diagnosed with TTTS, with no outstanding history of medication use during pregnancy, and no family history of genetic disorder or twin pregnancy. In the donor twin, persistently absent end-diastolic flow in the umbilical artery was observed using Doppler velocimetry. Polyhydramnios was observed in the recipient twins. The fetal weight discordance between the twins was 39%. After 2 weeks of follow-up, the authors performed fetoscopic laser photocoagulation and successfully ablated five vascular anastomoses and amnioreduction by 2.5 l. Five days after the laser surgery, the patient developed amniotic fluid leakage, and an amniopatch was performed. The authors did the caesarean section at 34 weeks because of severe preeclampsia, the donor and recipient birth weights were 1,120 g and 1,837 g, respectively (weight discordance 39%). The APGAR scores were 3/4 and 6/8, respectively. The donor twin died 6 days after delivery due to respiratory failure, and the recipient twin survived. Neonatal echocardiography of the surviving twin showed no tricuspid regurgitation. No long-term follow-up was performed.

Clinical discussion

The traditional diagnostic criteria for TTTS stage 3 were not met and overlapped with the diagnostic criteria for sIUGR type 2. This is the first procedure reported in Indonesia for atypical TTTS with the outcome, one twin survived.

Conclusion

Some TTTS cases do not meet traditional diagnostic criteria and overlap with other monochorionic twin complications.

Management of atypical cases of twin-to-twin transfusion syndrome

Up to 20% of monochorionic diamniotic twin pregnancies can be complicated with twin-to-twin transfusion syndrome (TTTS). This complication is diagnosed by ultrasound demonstrating amniotic fluid discordance between both amniotic sacs, with polyhydramnios in the recipient's sac and oligohydramnios in the donor's, secondary to an imbalance in blood volume exchange between twins. Ultrasound evaluation of the amniotic fluid volume, bladder filling, and assessment of fetal Doppler parameters provide the basis for classification of TTTS, allowing severity assessment. The Quintero's staging system provides a standardized prenatal estimate on the risk of intrauterine fetal demise of one or both twins and the need for fetoscopic laser coagulation of placental vascular anastomoses or delivery depending on the gestational age. However, a proportion of TTTS cases may present without a linear progressive deterioration and no ultrasound signs of preceding staging, in rare situations, they arise even without amniotic fluid discordance. Thus, these unusual clinical presentations of TTTS have long been grouped into the category of atypical TTTS. In this review, we show the clues for diagnosis and management of different atypical cases of TTTS highlighting their underlying mechanism to improve the clinical understanding of such atypical situations, avoid misdiagnosis of TTTS, and allow a timely referral to a fetoscopic center.

Twin-to-twin transfusion syndrome: Controversies in the diagnosis and management

In twin-to-twin transfusion syndrome (TTTS) communicating placental vessels on the chorionic plate between the donor and recipient twins are responsible for the chronic imbalance of blood flow. Evidence demonstrates that fetoscopic laser ablation is superior to serial amnioreductions in terms of survival and neurological outcome for stages II-IV TTTS. However, the optimal management of stage I TTTS remains poorly understood. It is well established that all chorionic plate anastomoses should be closed by laser ablation. Compared to the selective laser method, the Solomon technique yields a significant reduction of recurrent TTTS and post-laser twin anemia polycythemia sequence (TAPS). Over the past 25 years, survival rates after fetoscopic laser surgery have significantly increased. High volume centers report up to 70% double survival and at least one survivor in >90% cases. In this review, we discuss the controversies in the diagnosis and management of TTTS, especially, the optimal management in stage I cases, very early or late diagnosis, and the optimal laser technique. Furthermore, we will discuss a stage-related outcome after laser surgery and examine whether it is necessary at all to distinguish between stages I and II. Finally, the optimal timing as well as mode of delivery after TTTS laser treatment will be discussed.

Fortnightly surveillance of monochorionic diamniotic twins for twin to twin transfusion syndrome: Compliance and effectiveness

OBJECTIVES

To determine the compliance and effectiveness of fortnightly ultrasound surveillance for detection of twin-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twin gestations.

METHODS

This is a retrospective study of ultrasound surveillance of MCDA twins for TTTS. Our surveillance protocol requires fortnightly ultrasounds starting at 16 weeks of gestational age (GA) continuing until delivery. Compliance was assessed by determining the GA of surveillance initiation and time between ultrasounds. GA and Quintero Stage at diagnosis were evaluated to determine whether TTTS was detected prior to advanced disease (Quintero Stage III +) or fetal demise.

RESULTS

Of 442 women, 264 (59.7%) initiated surveillance after 16 weeks; follow-up ultrasounds were late in 17.4% of cases. TTTS was diagnosed in 43 (9.7%) women at a median GA of 19.7 [17.4, 23.9] weeks. Of 25/43 (58.1%) cases diagnosed during protocol compliance, 12 had advanced disease and two had fetal demise. A similar proportion of diagnoses (n = 18), made while non-compliant, exhibited advanced disease (11/18, 61.1%, P = .40). Thirteen diagnoses occurred during periods of increased ultrasound frequency due to abnormalities (ie, fluid/estimated fetal weight discrepancies or Doppler abnormalities).

CONCLUSIONS

In this population, fortnightly ultrasound compliance was suboptimal. Advanced disease and fetal demise occurred during protocol compliance.

The Amniotic Fluid Proteome Differs Significantly between Donor and Recipient Fetuses in Pregnancies Complicated by Twin-to-Twin Transfusion Syndrome

BACKGROUND

Twin-to-twin transfusion syndrome (TTTS) is a serious complication of monochorionic twin pregnancies. It results from disproportionate blood supply to each fetus caused by abnormal vascular anastomosis within the placenta. Amniotic fluid (AF) is an indicator reflecting the various conditions of the fetus, and an imbalance in AF volume is essential for the antenatal diagnosis of TTTS by ultrasound. In this study, two different mass spectrometry quantitative approaches were performed to identify differentially expressed proteins (DEPs) within matched pairs of AF samples.

METHODS

We characterized the AF proteome in pooled AF samples collected from donor and recipient twin pairs (n = 5 each) with TTTS by a global proteomics profiling approach and then preformed the statistical analysis to determine the DEPs between the two groups. Next, we carried out a targeted proteomic approach (multiple reaction monitoring) with DEPs to achieve high-confident TTTS-associated AF proteins.

RESULTS

A total of 103 AF proteins that were significantly altered in their abundances between donor and recipient fetuses. The majority of upregulated proteins identified in the recipient twins (including carbonic anhydrase 1, fibrinogen alpha chain, aminopeptidase N, alpha-fetoprotein, fibrinogen gamma chain, and basement membrane-specific heparan sulfate proteoglycan core protein) have been associated with cardiac or dermatologic disease, which is often seen in recipient twins as a result of volume overload. In contrast, proteins significantly upregulated in AF collected from donor twins (including IgGFc-binding protein, apolipoprotein C-I, complement C1q subcomponent subunit B, apolipoprotein C-III, apolipoprotein A-II, decorin, alpha-2-macroglobulin, apolipoprotein A-I, and fibronectin) were those previously shown to be associated with inflammation, ischemic cardiovascular complications or renal disease.

CONCLUSION

In this study, we identified proteomic biomarkers in AF collected from donor and recipient twins in pregnancies complicated by TTTS that appear to reflect underlying functional and pathophysiological challenges faced by each of the fetuses.