Effect of aspirating needle calibre on outcome of in-vitro fertilization

Thirty patients with intact ovaries undergoing ultrasound-guided transvaginal oocyte retrieval for in-vitro fertilization treatment had their ovaries randomized for follicular aspiration with small and large aspiration needles while under mild sedation. Collections using smaller diameter needles had no significant effect upon the number of oocytes collected per follicle aspirated, or on the subsequent fertilizing capacity of those oocytes. There was significant reduction in pain perceived by the patient when the smaller needle was used during the collection.