Clinical Significance of Ultrasonography Markers in Prenatal Diagnosis of Turner Syndrome in Fetuses-90 Cases Reports
Author(s): Allybocus Zubair Akbar
Objective: To evaluate the clinical significance of ultrasonography markers in prenatal diagnosis of Turner syndrome in fetuses.
Methods: Retrospectively 90 karyotypically documented fetuses with Turner syndrome reviewed from our database between August 2010 and April 2018 made up our study population. Women were aged between 19 to 40 years and weeks of gestation from 9 to 32 weeks. Ultrasound findings documented by skilled sonographer, performed in a systemic order from fetal head to toe, indicative of turner syndrome were noted, grouped and tabulated. Advanced maternal age women had routine fetal karyotyping while for younger women, it was indicated after abnormal ultrasonic findings. Amniocentesis or chorionic villus sampling were source for fetal chromosome extraction for karyotyping. Karyotyping (G-banding) was performed under standard protocol and karyotypes were described according to the International System for Human Cytogenetic Nomenclature. The karyotypes results were grouped as pure monosomy, 45X, and Mosaics In the evaluation of clinical significance of ultrasound markers, P values lower than 0.001 were considered as statistically significant. The calculations were performed using a statistical package program.
Results: 61 fetuses were diagnosed in <30 yr group of which 48 (78%) 45X vs 17 (18%) mosaic, 17 fetuses in 30-35 yr with 7 (41%) 45X vs 10 (58.8%) mosaic and 12 fetuses in >35yr group as 6 (50%) 45X vs 6 (50%) mosaic. 32 fetuses were diagnosed as Turner syndrome in <12 weeks period of which 31 (96%) 45X vs 1 (4%) mosaic, 27 fetuses in 12-20 weeks period of which 20 (33%) 45X vs 7 (24%) and 31 in >20 weeks period as 10 (16%) 45X vs 21 (72%) mosaic. From ultrasound findings, 25 fetuses were diagnosed as intrauterine death, of which 24 (96%) 45X vs 1(4%) mosaic, (p<0.001) and 20 (80%) of them occurring in <12 weeks period (p<0.001). From 90 fetuses, 27 (30%) had cystic hygroma of which 27 (100%) 45X vs “0” (0%) mosaic, p<0.001. 21(23.3%) fetuses showed skin edema of which 21 (100%) 45X vs “0” (0%) mosaic, p<0.001. 11 fetuses showed cavity effusion of which 11 (100%) 45X vs “0” (0%) mosaic, p<0.001.
Conclusion: The cluster of ultrasonography findings; intrauterine death, cystic hygroma, skin edema and cavity effusion showed a statistically significant impact (p<0.001) for the prenatal ultrasound diagnosis of Turner Syndrome. About 96% of 45X fetuses are spontaneously lost in early trimester. Of those surviving to second trimester, almost 100% will express one or more of the cluster of findings while the mosaic fetuses hardly express any, (p<0.001). The clinical significance is that 45X fetuses are diagnosed in early trimester while the mosaic fetuses later in 2nd-3rd trimester or even postnatal, (p<0.001). Clinically the cluster of ultrasonography findings are highly predictive of TS whenever present, (p<0.001) while absence does not rule out TS but their presence are dependent on karyotype of fetus (p<0.001). Conclusively, though karyotyping remains the gold standard for definitive diagnosis of Turner syndrome, we confirmed the clinical importance of these ultrasonography findings as fundamental markers for the prenatal ultrasound diagnosis of fetuses.