Background and Aim Congenital malformations and chromosomal abnormalities are important problems for the neonatal morbidity and mortality especially in well developed countries. In this study we investigated the prevalence and distribution of the chromosomal abnormalities in our NICU.
Method Chromosomal abnormalities identified between 2008 and 2012 were retrospectively analyzed. Also, demographic features and concomitant congenital malformations were also collected. Cytogenetic analysis was performed on peripheral blood of newborns by standard chromosomal analysis methods. According to our hospital protocols, newborns with more than one major malformation or with 1 major plus 2 minor abnormalities were scheduled for chromosomal abnormalities.
Results During the study period, 431 chromosomal analyses (3.2%) were performed among the 5170 hospitalized newborns. 78.4% of the cases had normal chromosomal karyotype. Consanguinity rate was 27.9%. Major chromosomal abnormality rate was 1.8%.
Frequency of chromosomal abnormalities were as follows; Trisomy 21 13.5% (n=58), trisomy 18 2.3% (n=10), trisomy 13 1.2% (n=5), 45 XO 0.5% (n=2) and other chromosomal abnormalities were 4.2% (n=18). Congenital heart abnormalities (85.9%), cranio-fascial abnormalities (44.6%) and genito-urinary anomalies (16.9%) were most common concomittant malformations. Cardiovascular abnormalities were most common malformations in newborns with trisomy 21.
Conclusion Frequency and distribution of the chromosomal abnormalities in our NICU were similar compering with other populational studies. Trisomy 21 was most common chromosomal abnormality. Newborns with malformations in more than two organ system should be investigated chromosomally as well.