Modern ultrasound imaging can identify and measure small subcutaneous collections of fluid behind the necks and backs of fetuses during the late first trimester. Amniocentesis is another way to test for Down syndrome. It is performed by piercing the amniotic sac and drawing out some of the fluid surrounding the baby. Health and developmental problems occur in the child during the first years of life, close monitoring is necessary throughout this period. Children with Down syndrome are more susceptible to infections than normal children and, as a result often suffer chronic respiratory infection, recurrent pneumonia and repeated bouts of tonsillitis.
Researchers believe that children have a deficient immune response.
Development delays are evident from the early months of life. Infants are slow to turn over, sit stand, speak and respond. This may be due to the mental retardation caused by the disease. Studies on infants with Down syndrome show that the brain is virtually normal size and structure for at least a few months after birth. Hearing loss occurs more frequently among individuals with Down syndrome than in the normal population.