A prospective randomized study comparing needles of different diameters for transvaginal ultrasound-directed follicle aspiration

Abstract

To determine whether the use of smaller diameter needles at oocyte collection reduces pain without jeopardizing the treatment outcome. Prospective randomized study. The Assisted Conception Unit, Kings College Hospital, United Kingdom. One hundred twelve patients undergoing an IVF-ET treatment cycle. Study patients were aged < or = 38 years and had at least six follicles > 14 mm on the day of oocyte collection. Patients were randomized to follicle aspiration with a 15- (n = 34), 17- (n = 41), or 18- (n = 37) gauge (g) single channel needle. Intravenous pethidine and diazepam were used for analgesia and sedation. Pain was quantified by means of questionnaires completed by the patient and by her partner postoperatively. A greater proportion of patients reported severe to unbearable pain with the 15-gauge compared with the 17-gauge (44% versus 22%) or 18-gauge (44% versus 16%) needles. Partners' perception of severe pain experienced by patients showed the same trend when the 15-gauge was compared with the 17- (62% versus 29%) and 18-gauge (62% versus 22%) needles. There was no significant difference between the needles regarding the oocyte collection rate, fertilization rate, proportion of oocytes with fractured zonae, cleavage rate, implantation rate, and pregnancy rate per cycle. Reducing the size of the needle used for oocyte collection from 15 to 17 or 18 gauge reduces pain without affecting the number of oocytes collected, their quality, or the clinical pregnancy rate.