Correlation between follicular diameters and flushing versus no flushing on oocyte maturity, fertilization rate and embryo quality

Abstract

Objective To determine (a) the correlation between follicular sizes, oocyte maturity, normal fertilization rate, cleavage and embryo quality; and (b) to establish whether oocytes recovered with or without follicular flushing have different developmental competence. Design Prospective observational study. Setting Academic medical center. Patients Forty nine cycles (37 ICSI and 12 IVF). Interventions Measurement of 360 follicular diameters on the day of egg retrieval and classification into three groups Group A (mean diameter 12-14.5 mm.), group B (mean diameter 15-18 mm.) and group C (diameter >18.5 mm.). Main outcome measure Correlation between follicular size at the time of retrieval and oocyte maturity, fertilization and cleavage rate in 226 oocytes (163 ICSI and 63 IVF). Developmental competence of oocytes retrieved with flushing versus non flushing. Results Almost all (99 %) of the oocytes recovered from follicles of group C were in metaphase II as opposed to 80 % in group A and 81 % in group B (p <0.01). Overall there was a progressive and significant increase in fertilization rates from group A follicles to group C (47 % vs. 67 %, p 0.05). Overall 53 % of oocytes retrieved from group A follicles showed either no fertilization or abnormal fertilization versus 27 % in group C (p 0.05). The oocyte recovery rate with follicular flushing improved from group A to group B and to group C follicles (65 % vs. 49 % vs.37 % respectively p <0.01). There were no differences in rates of immature oocyte, fertilization, abnormal or not fertilization and cleavage. Conclusions The results of this study shows that: a) Follicles larger than 18 mm at retrieval have consistently mature oocytes with a higher rate of fertilization; b) Small size follicles are still capable of containing mature oocytes, but their rate of abnormal or no fertilization is high; c) Oocytes recovered with flushing are still able to produce embryos with full developmental competence.

Relationship between follicular volume and oocyte competence, blastocyst development and live‐birth rate: optimal follicle size for oocyte retrieval

“…However, according to our data, MII oocytes from small follicles showed similar capacity in terms of FR compared with oocytes from follicles of ≥ 2 mL. This finding is in line with those of some previous publications 5,7,9,10 , although not others 6,27 . Similarly, published data regarding embryo cleavage rates and embryo quality in relation to follicle size are inconsistent [9][10][11][12] .…”

“…Previous studies have reported lower oocyte recovery and reduced MII oocyte rates in small follicles (< 2 mL). However, according to our data, MII oocytes from small follicles showed similar capacity in terms of FR compared with oocytes from follicles of ≥ 2 mL.…”

“…This study demonstrates that oocytes derived from small follicles have the capacity for normal development and subsequent delivery of healthy children, indicating the usefulness of puncturing this follicle cohort. Previous studies have reported lower oocyte recovery and reduced MII oocyte rates in small follicles (< 2 mL) 2,5,7,27,28 . However, according to our data, MII oocytes from small follicles showed similar capacity in terms of FR compared with oocytes from follicles of ≥ 2 mL.…”

Association of follicular fluid volume with membrane stretchability of human metaphase II oocytes following the gonadotropin‐releasing hormone agonist protocol during intracytoplasmic sperm injection

“…Even if the COC was obtained, the rate of mature oocyte retrieval was low and that of immature oocyte retrieval was high. Several previous studies have reported that the oocyte maturity rate is associated with the follicular volume/diameter, which is consistent with the current findings.…”

Oxidative homeostasis in oocyte competence for in vitro embryo development

“…However, besides ROS and GSH, the oocyte competence in maturation is also related to other factors, such as cumulus cell expansion, gene expression, structural organization, and mitochondrial replication, among many others (De Bem et al, ; Kahraman et al, ; Lamas‐Toranzo, Pericuesta, & Bermejo‐Alvarez, ; Nivet, Leveille, Leader, & Sirard, ). Thus, it is suggested that the discontinuation of folliculogenesis at different stages of oocyte development is responsible for the unregulated levels of ROS, GSH, and other factors, thereby promoting reduction in oocyte competence for subsequent development (De Bem et al, ; Coticchio et al, ; Han et al, ; Mehri et al, ).…”