Gestational outcomes of pregnant women who have had invasive prenatal testing for the prenatal diagnosis of spinal muscular atrophy

Background. Spinal muscular atrophy (SMA) is a neurodegenerative disease which is characterised by progressive degeneration of motor neurons in the anterior horns of the spinal cord. It is a mainly chromosome 5-linked genetic disorder, with recessive inheritance and it can be diagnosed prenatally. Objective. To communicate the importance of prenatal diagnosis of spinal muscular atrophy (SMA) and to demonstrate the gestational outcomes of disease carrier pregnant women who have had invasive prenatal testing (IPT). Methods. We retrospectively evaluated 113 pregnancies of 76 patients who were referred to the Division of Perinatal Medicine at Haçettepe University in Ankara, Turkey for the prenatal diagnosis of SMA between 2000 and 2015. We evaluated the screening results and gestational outcomes of the patients. The pregnancy outcomes were compared with a control group of 179 patients. The Beksac Obstetrics Index (BOI) was used for the comparison of obstetrical histories/backgrounds of the study and control groups. Results. Chorionic villus sampling (CVS) and amniocentesis (AC) were performed in 83 (73.5%) and 30 (26.5%) cases, respectively. In 24 cases (21.2%), the fetuses were found to be disease-positive and 23 of them were terminated. The median gestational day at birth (p<0.001), median birthweights (p=0.002) and median BOI (p=0.001) of the study and control groups were compared and the differences were statistically significant. Conclusion. Prenatal diagnosis of SMA is very important and a nationwide special antenatal care programme must be established for better diagnosis and eradication of this genetic disorder.