A pilot trial of large versus small diameter needles for oocyte retrieval

BACKGROUND This study was designed to determine whether small diameter needles for oocyte retrieval alter oocyte yields in patients undergoing IVF in comparison to standard large diameter needles. METHODS We conducted a prospective pilot study of 21 consecutive favorable prognosis patients. In each patient one ovary was randomly allocated to retrieval with either a 20 G/ 35 mm (thin) or 17 G/ 35 mm (standard) needle, the other ovary was then retrieved with the opposite needle. RESULTS The standard diameter needle was used to collect a total of 215 oocytes from 355 aspirated follicles (60.6%) compared to 203 oocytes from 352 aspirated follicles (57.7%) with the thinner needle (p = 0.23). Stratifying outcomes by anti-Müllerian hormone (AMH), as indicator of ovarian reserve, and by body mass index (BMI) the oocyte yields, still, did not differ (AMH, r (17) = -0.20, p = 0.44; BMI, r (17) =0.02, p = 0.96). Outcomes also did not vary among women with diminished ovarian reserve (p = 0.17) and in women with normal ovarian reserve (p = 1.00). Operating time was, however, significantly increased by 3.3 minutes per ovary (z = -3.08, p = 0.002) with the thinner needle. CONCLUSIONS Needle diameter does not affect oocyte yield, including in obese patients and patients with diminished ovarian reserve. Thinner needles appear to significantly prolong operating time.