Outcome of fetuses with Turner syndrome: a 10-year congenital anomaly register based study

Objective. To describe the characteristics and outcome of fetuses with Turner syndrome reported to a national congenital anomalies register. Methods. All cases with a diagnosis of Turner syndrome reported to Congenital Anomaly Register and Information Service for Wales (CARIS) between 1 January 1998 and 31 December 2007 were included. The cases were grouped in five categories based on their outcomes: fetal loss (FL), termination of pregnancy (TOP), live birth (LB), and postnatal (PN) detection and comparison was undertaken between the groups. Results. One hundred twenty-four cases were reported during the study period. The prevalence of Turner syndrome was 1 in 4901 live female births. Seventy-four percent had 45 X karyotype while the rest had some form of Mosaic Turner karyotype. Pregnancy was terminated in 66% of antenatally diagnosed cases. FL and TOP groups had 92% and 87%, respectively, of 45 X karyotype - far greater than in the LB and PN groups. Increased nuchal thickness was the commonest anomaly noted in antenatal ultrasound and was a predictor for 45 X karyotype, FL, and termination. Conclusion. Termination was the most common outcome of fetuses diagnosed antenatally with Turner syndrome. This has modified the natural history of Turner syndrome particularly in cases with Mosaic karyotype.