There are four parts of IVF that have the potential to cause discomfort Injections of fertility medications: Most of the injections used during IVF use very small needles that just go under the skin. These are called subcutaneous injections. Monitoring: You will need to come to the office periodically for blood tests and transvaginal ultrasounds, which have about the same level of discomfort as a pap smear. Ovaries getting larger: More eggs maturing at the same time can cause your ovaries to be larger than usual, leading to bloating, cramping, or abdominal fullness. Egg retrieval: This is performed under anesthesia to remove eggs from the ovaries, which is uncomfortable but you won’t feel it due to the anesthesia.