Hi Nitya, hope you are doing well. Buddy who told you this? This is not like this. The baby will be same. No matter he/she is naturally conceived or you use any treatment or assisted conception technique. I am not a doctor. I am a patient myself. I am trying to conceive for about 10 years now. I have gain all related information from different clinics. There is only way that IVF baby can have health issues.That is due to genetic or heredity issues. If the egg and sperm is infected only then child can have health issues. You can simply have proper screening of egg and sperm before embryo growth. Infact good clinics approve eggs and sperm after screening. So dont worry and Good Luck!