Does a Large (>24 mm) Follicle Yield a Competent Oocyte/Embryo?

Abstract

Aim: To evaluate the effect of large follicular size (≥24 mm) at day of oocyte retrieval on oocyte/embryo quality.

Patients and methods: A cohort study was conducted in a single tertiary medical center between July 2018 and May 2019. Before ultrasound-guided follicular aspiration, follicles were measured and divided into 2 groups according to their maximal dimensional size: large: ≥24 mm and normal: <24 mm. Microscopic examination of the follicular aspirates was performed by an embryologist. Each follicle aspirated was evaluated for oocyte maturation, oocyte fertilization, and embryo quality.

Results: 428 follicles were measured, including 383 (62.81%) in the normal and 45 (14.06%) in the large follicle groups. Oocytes were achieved during aspiration from 297 (75.5%) and 29 (64.4%) of the normal and large follicle groups, respectively (p = 0.05). No in-between group differences were observed in mature oocyte (MII), fertilization, and top-quality embryo (TQE) rates. Nevertheless, once a zygote (2PN) was achieved, a trend toward a higher TQE rate/2PN was found in the large follicle group (16/19 [84.2%] vs. 115/171 [67.3%]; p = 0.062).

Conclusion: While a nonsignificant decrease in oocyte recovery rate was found in follicles ≥24 mm, the zygote and TQE per follicle were comparable.

Keywords: Follicle size; Oocyte maturation.

© 2020 S. Karger AG, Basel.