<s>[INST] Dear Doctor, My ultrasound shows thickening of endometrium (day 10 the same is 10 mm). Also some polypoidal thickening. Can this be the reason for non implantation of embryo? Would this affect my chances of success in ivf? I have been trying to coceive naturally for last 5 years. Had conceived naturally once but suffered miscarriage. Would be really thankfull for your guidance. [/INST] HelloThanks for writing to us with your health concern.Proliferation and development of the endometrium ( lining of the uterus ) is normal during the cycle. 10 mm on day 10 is slightly on the higher side.However, polypoidal thickening is not normal.It can definitely impact the implantation of the embryo.However it is not a total contraindication for pregnancy.It would slightly reduce your chances of conceiving from the IVF procedure.Since you are yet to go for the process, dont worry about what you cannot change right now.If the endometrium is not favourable, your doctor certainly wont go ahead with the pickup and transfer.Just dont stress out and stop worrying.A slightly more than normal thickened endometrium might sometimes be favourable for implantation - you never know !JUst keep your fingers crossed.All the bestTake care. </s>