Implications Of Sex Determination Tests
Sex determination is the prenatal testing for detecting the sex of a foetus. Thought this determination is medically important for a few diseases which are sex-linked, there is a possibility that this testing may be misused for female foeticide.
Some diseases are recessive, example colour blindness, haemophilia A and Duchenne muscular dystrophy. If a woman carries a recessive condition, her son has a 50 per cent risk of being affected and her daughter a 50 per cent chance of being a carrier of the disease. Males are mostly affected as they lack a second X chromosome.
Methods For Sex Determination
Pre-lmplantation Genetic Diagnosis (PGO) This refers to the genetic profiling of the embryos treated by IVF before transferring them into the uterus. Embryos are screened in women who are elderly (37 years) have repeated abortion or have a family history of genetic diseases. The sex- chromosome can also be known and the desired embryo can be implanted in the uterine cavity.
• Cell-Free Fetal DNA Testing This is a recent innovation and non- invasive diagnosis as a small amount of foetal cells is found in the maternal blood after seven-eight weeks. The mother’s blood ¡s collected and the foetal cells are isolated and sent for DNA sequencing after which the sex chromosomes can be detected.
• Chononic Villus Sampling (CVS) This procedure entails the sampling of the chorionic villus (placental tissue) to test the chromosomes. It is preformed between 10-12 weeks of the pregnancy.
Risks
- Infection
- Limb detects in baby
- Abortion
- Amniocentesis
This is an invasive test done on the amniotic fluid. Small amount of fluid from the amniotic sac surrounding the foetus is sampled under USG guidance. And the foetal DNA is analysed. This is done during 14-16 weeks of pregnancy. The risks involved with this, are similar to the ones in CVS.
Ultrasonography (USG)
A foetal scan is an accurate method to detect the gender by the 14th week of pregnancy. The accuracy increases as the pregnancy advances, by inspection of the external genitalia.
Implications
Some diseases affects the foetus depending on its sex. If the gender is determined, further tests can be conducted to confirm whether the foetus is affected.
Concerns
India has an alarming gender imbalance as female foeticide is being practised in many parts. The sex determination tests became a big business shortly after its introduction in India, due to the preference of a male child.
These tests should be done only for medical reasons. Prenatal sex determination was banned ¡n India ¡n 1994 with the aim of preventing sex- selective abortion. So, the disclosure of the foetal sex in USC and genetic testing is illegal. Even so, laws will not suffice. People have to change their outlook.