Techniques used to diagnose BDs
Table 5 shows the techniques that were used to diagnose BDs. For BDs as a whole, 73.45% were diagnosed using ultrasonography, 30.02% were diagnosed using clinical tests, and 4.86% were diagnosed using chromosomal testing. Ultrasonography was the technique that was most commonly used for the identification of congenital heart defects (93.00%), congenital hydrocephalus (94.11%), cleft lip with cleft palate (86.50%), cleft lip without cleft palate (72.54%), limb reduction defects (70.93%), congenital diaphragmatic hernia (85.93%), and congenital malformation of the urinary system (93.32%). Clinical testing was the technique that was most commonly used for congenital talipes equinovarus (56.04%), and chromosomal testing was the technique that was most commonly used to diagnose trisomy 21 syndrome (85.06%) and other chromosomal malformations (79.88%).