There was a time when parents had to wait till birth of the newborn to know whether it is boy or girl. But technology is improved; ultrasound scan now can determine the baby’s sex after 12 weeks of pregnancy. But for some cases it is too long. Because there are some genetic diseases where only boys are affected. So, early prediction is required. Pregnant mother’s blood contains foetal DNA and this may indicate the baby’s sex after seven week of pregnancy which is about 98% reliable.
Journal of the American Medical Association reports this; it also says test before seven weeks or urine based tests are not reliable.
But there is concern among many that some parents will opt for abortion, if they don’t find desired sex of the baby. In India and China many parents choose abortion of female fetus which is unethical and a threat to gender balance.