OP26.02: A systematic review of diagnosis, management and outcomes for Twin–twin transfusion syndrome (TTTS) diagnosed before 18 weeks' gestation

Abstract

Current management protocols for TTTS are optimised for twins at 18-24 weeks gestational age (GA), however, up to 25% of cases of TTTS may be diagnosed <18 weeks GA. Methods which could be used prior to fusion of amnion and chorion are needed. We systematically reviewed the published literature on diagnosis, management and outcomes of TTTS diagnosed at <18 weeks GA. PubMed and Scopus databases were searched for articles regarding early onset TTTS, from inception to April 2016. All studies types with primary data on TTTS <18 weeks GA in MCDA pregnancies were included. Exclusion criteria included studies not in English, higher order pregnancies, and diagnosis >18 weeks. Studies were independently assessed for inclusion by two reviewers. Authors of those with incomplete data were contacted. Data was extracted for study characteristics, interventions and outcomes and entered into an Excel spreadsheet and outcomes analysed. 16 studies included for analysis assessed 171 pregnancies. Earliest gestation at diagnosis was 14 weeks. 6 papers used DVP discrepancy for diagnosis, 6 used Quintero staging and the remaining used custom methods, TAPS diagnosis or unspecified criteria. The majority had treatment with laser in 88.9% of pregnancies; median gestational age at laser was 17+0 (range 16+0-21+6). The next commonest intervention (6.4%) was selective reduction. 2.3% underwent amniodrainage and 2.3% of pregnancies were terminated. Median gestational age at delivery was 31+3 (range 23+0-39+5). The rate of double twin survival at birth was 59.8%; at least one twin survived in 80.4% cases and 18.5% pregnancies had no survivors. Heterogeneity in outcomes was high. Outcomes of early gestation TTTS are better than expected. Management of TTTS at <18 weeks GA requires standardisation to standard management protocols. Adjustments of diagnostic criteria and the use and timing of existing invasive and emerging non-invasive treatment options that can be used at earlier gestations should be explored.