Twin-to-twin transfusion: update on management options and outcomes.

PURPOSE OF REVIEW: The diagnosis and treatment of twin-to-twin transfusion syndrome has progressed to a staging system to allow directed therapy with the addition of laser to traditional serial amnioreduction. The management options and outcomes are reviewed here. RECENT FINDINGS: In three observational and one randomized controlled trial, laser photocoagulation of chorionic plate vessels at the intertwin membrane improved perinatal survival of at least one fetus and reduced neurological morbidity. Cerebral palsy continues to be a major contributor to adverse outcome with rates of around 20% for survivors. SUMMARY: Treatment strategies for this condition have remained controversial, but two main approaches have been commonly used. Serial, aggressive amnioreduction and fetoscopic laser photocoagulation of the chorionic plate vascular anastomoses at the intertwin membrane. Using the former technique, survival rates of between 18 and 83% have been described. However, 5-58% neurological morbidity has been demonstrated in the surviving infants treated by serial amnioreduction alone. Laser photocoagulation has been advocated in a few specialist centres. Such treatment has been associated with survival rates of between 55 and 69% and potentially reduced neurological morbidity of between 5 and 11% in surviving infants.

A comparison of fetal organ measurements by echo-planar magnetic resonance imaging and ultrasound.

OBJECTIVES: To compare fetal organ size measured using echo-planar magnetic resonance imaging and 2D ultrasound. To determine the relative accuracy with which each technique can predict fetal growth restriction. DESIGN: A cross sectional, observational study comparing two different measurement techniques against a gold standard, in a normal clinical population and an abnormal population. SETTING AND POPULATION: Seventy-four pregnant women (33 who were ultimately found to be normal and 37 with fetal growth restricted fetuses) were recruited from the City Hospital Nottingham UK to be scanned once (at various gestations). METHODS: Each fetus had a standard ultrasound biometry assessment followed by magnetic resonance imaging measurement of organ volumes. MAIN OUTCOME MEASURES: For each measurement for both techniques, the normal population was plotted with 90% confidence intervals. Fetal growth restricted subjects were compared with the normal population using this plot; 2 x 2 tables were created for each measurement. This was used to calculate the relative sensitivities and positive predictive value of the different measurements. A Bland-Altman plot was used to compare the ultrasound and magnetic resonance imaging measurements of fetal weight. RESULTS: Brain sparing was seen in ultrasonic head circumference measurements, but an overall reduction in fetal growth restriction brain volume was apparent using magnetic resonance imaging at late gestations. Across the whole range of gestational ages, ultrasound assessment of fetal weight was the best predictor of fetal growth restriction. CONCLUSION: Ultrasound fetal weight assessment appears to identify more fetuses with fetal growth restriction than abdominal circumference. The brain sparing apparent in ultrasonic head circumference measurements of fetuses with fetal growth restriction masks a reduction in brain volume observed with magnetic resonance imaging.

Serial aggressive platelet transfusion for fetal alloimmune thrombocytopenia: platelet dynamics and perinatal outcome.

OBJECTIVES: Our purpose was to describe the fetal loss rate and platelet dynamics in fetal alloimmune thrombocytopenia managed by serial platelet transfusions. METHODS: Retrospective analysis over 10 years of consecutive pregnancies affected by fetal alloimmune thrombocytopenia requiring in utero platelet transfusions. RESULTS: There were 2 perinatal losses in 12 pregnancies managed by 84 platelet transfusions. One was obviously procedure related from exsanguination despite platelet transfusion. The attributable procedure related fetal loss rate was 1.2% per procedure but 8.3% per pregnancy. The median rate of fall in fetal platelet count per day after transfusion was lower at the placental cord insertion (n = 54) 40.5 x 10(9)/L (range, 5.4-96.1 x 10(9)/L) compared with that at the intrahepatic vein (n = 30) 50.9 x 10(9)/L,(range, 29.5-91 x 10(9)/L) (P = .0009). CONCLUSION: Pooling our results with those previously published yields a cumulative risk of serial weekly transfusions of approximately 6% per pregnancy, indicating the need for development of less invasive approaches.