Down syndrome is a congenital condition characterized by retarded mental and physical development of the child. Some of the distinct features include the presence of poor muscle tone, a flattened facial profile and nose, short neck, small head, upward slanting eyes ears, and mouth. There is also an increased risk for health problems. Genetically speaking, the person has three copies of chromosome 21, instead of the usual two copies in all cells. It is also called as trisomy 21 because of the presence of an extra chromosome caused by abnormal cell division during the development of the sperm cell or the egg cell. It is a relatively common genetic disorder at birth especially in case of older age pregnancy. Possibly, the egg quality diminishes with age and causes more embryos to be chromosomally abnormal.
Parents of a child with a genetic disorder such as Down Syndrome are always worried about the possibility of the same problem occurring in a future pregnancy. The question is frequently posed to the family doctor taking care of a pregnant mother. Gynaecologists always face this question the possibility can be determined at an early stage of pregnancy when the same can be legally terminated. This is a very difficult question which can be answered only by pre-implantation genetic tests by a qualified and experienced doctor – the best gynaecologist.Pre-implantation Genetic Diagnosis (PGD) involves the testing of pre-implantation stage embryos or oocytes for genetic defects. PGD is done for couples whose potential offspring are at risk of severe Mendelian disorders, structural chromosome abnormalities or mitochondrial disorders. Besides Down Syndrome, many other common as well as rare diseases can also be diagnosed in this fashion, such as serious lung disease Cystic fibrosis, neurological diseases such as spinal muscular atrophy, and Duchenne’s muscular dystrophy and blood diseases such as hemophilia, Sickle cell disease and thalassemia. PGD is especially helpful when one or both genetic parents has a known genetic abnormality.
IVF is required to obtain embryos for PGD. During IVF, PGD is performed before embryo transfer to select eggs without a known or suspected gene problem to remove the possibility of the genetic disorder. Assisted hatching is done after eggs are retrieved and fertilized in the laboratory.
There is also some evidence to suggest that PGS testing reduces miscarriages. It is particularly important in case of women of older than 35 years of age. Moreover, screening embryos with PGS and transferring only the ones that are chromosomally normal can increase IVF success rates.
According to the advice of the best gynaecologist in Chandigarh PGD is safe; most of the risks are similar to those for conventional IVF. Occasionally, mild reactions such as hot flushes, feeling down or irritable, headaches and restlessness may occur. These symptoms usually disappear after a short time.
