To determine the relation between chromosomal abnormality trisomy 21 and trisomy 18 in the pregnancy with respect to maternal age.
Materials and Methods: This was a screening study for trisomy 21 and 18 by a combination of maternal age, maternal serum biochemistry and foetal Nuchal Translucency (NT) and crown- rump length (CRL), conducted at one of the south Indian private medical college, Kerala. We screened 88 pregnant women during their 11-14 weeks of pregnancy from 10th February 2019 to 10th August 2020.
Results: The study included 86 singleton pregnancies and 2 twin pregnancies, mean age 26.53(SD±5.2), 74% were between 21-30 years of age and majority of them from 12 weeks of their pregnancy. In this study the mean CRL was 58.3(SD±10) and 5.7% (n=5) were chromosomally abnormal among this two were positive for Downs syndrome 60% (n=3), one was trisomy-18 20% (n=2), Nuchal translucency (NT) and age (P= 0.00: R2 =0.477), crown- rump length and age (P= 0.041: R2 =-0.219) have an association. The study shows an association with chromosomal abnormality with age (P= 0.00: R2 =0.00), NT (P= 0.00: R2 =0.00) and it has a correlation with CRL (R2=0.00), free 𝛽-hCG (R2=0.00).