Prevalence, natural history and clinical outcome of prenatally detected cerebral ventriculomegaly in twin pregnancies from the north of england. (7th June 2011) - Sethna, F
Abstract : Background: Few studies have reported on ventriculomegaly (VM) in twins or in relation to chorionicity. Methods: All twin pregnancies with suspected VM (n=67) occurring in Northern England during September 1994–December 2008 formed this population-based study. Data were obtained by cross-referencing with the Northern Congenital Abnormality Survey, the regional fetal medicine unit database, and the Northern Survey for Twins and Multiple Pregnancies. Results: VM was confirmed in 63 twin fetuses (26 monochorionic (MC); 37 dichorionic, DC). Prevalence rates during 1998–2008 were 56/10 000 twin births (95%CI 52 to 73), 122/10 000 MC births (95%CI 82 to 181) and 46/10, 000 DC births (95%CI 32 to 64). Concordance for VM in MC and DC twins was 23.1% and 10.8% respectively. MC twins: Eight cases occurred in pregnancies complicated by twin-twin-transfusion syndrome. Ten had prenatally detected associated anomalies (80% were nervous system anomalies); 4/10 were selectively terminated (sTOP). 2/26 had growth-restriction and 1/26 co-twin demise. Five were apparently isolated prenatally but three had anomalies diagnosed after delivery. DC twins: 16 cases had additional anomalies; eleven requested sTOP (nine in the third trimester; 2/9 laboured before the procedure could be performed). 3/37 followed co-twin demise, incorporating two livebirths with resolved VM. Seventeen cases were apparently isolated; VM persisted in all. The median gestation and atrial size at presentation were 25 weeks (IQR: 22–21) and 14.0 mm (IQR:11.0–21.5) respectively. 2/17 were sTOP (cephalocentesis required in one) and 15/17 were liveborn. Additional structural anomalies were identified following post-mortem or postnatal examination in five cases. Conclusion: Valuable outcome data relating to VM in twins is provided which will help with pre-natal counselling.