Effect of follicular size on oocyte retrieval, fertilization, cleavage, and embryo quality in in vitro fertilization cycles: a 6-year data collection

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.

“…In addition, the aspiration of follicles greater than 18 mm. provided the highest probability of retrieving mature oocytes (MII), confirming previous publications [2,3,6].…”

Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 97%

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

Mehri

Levi-Setti

Greco

et al. 2013

“…Many studies have demonstrated that the oocyte quality retrieved from large follicles is often better than that from small follicles [1][2][3], and those oocytes from large follicles tend to develop high quality embryos. Therefore, some clinicians argue that the timing of hCG triggering should be delayed to prolong the duration of ovarian stimulation and stimulate enough follicular growth.…”

Section: Introductionmentioning

confidence: 99%

Association between the proportion of dominant follicles and oocyte developmental competence

et al. 2014

Purpose To explore the optimal timing for hCG triggering by investigating the impact of different proportion of dominant follicles on the oocyte developmental competence. Methods One hundred ninety-eight infertile women were divided into three groups according to the proportion of dominant follicles on hCG day: (1) low: <15 % (n=66); (2) middle: 15-27 % (n=66); (3) high: >27 % (n=66). The grouping criteria were the bottom and top tertiles of the proportion of dominant follicles. Results The gonadotropin dosage, duration and maximum follicle diameter in the low proportion group were lower than those in the middle and high proportion groups. Oocyte maturation and the abnormal fertilization rate in the low proportion group were lower than those in the middle and high proportion groups. The normal fertilization rate did not differ among the three groups. The cleavage rate and number of transferable embryos in the low proportion group were significantly higher than those in the high proportion group. The high-quality embryo rate, implantation rate, and pregnancy rate in the low proportion group were significantly higher than those in the middle and high proportion groups.Conclusions A high proportion of dominant follicles are closely associated with impaired oocyte developmental competence and low pregnancy rate. These findings suggest that follicular overgrowth induced by delayed hCG triggering may undermine oocyte developmental competence and the proportion of dominant follicles may be a potential parameters for hCG triggering.

“…It has been reported that the differentiated status of granulosaluteal cells may affect the gene expression [22]. Follicle maturity has been related to follicle size, although the two are not totally dependent [23]. Unfortunately, the follicular size from which granulosa-luteal cells were obtained in the above studies was not mentioned [20,21].…”

Section: Discussionmentioning

confidence: 98%

Expression of inhibin-activin subunits, follistatin and smads in granulosa-luteal cells collected at oocyte retrieval

Chang

Kang

Lan

et al. 2006

Purpose: To examine the expression of inhibinactivin subunits, follistatin, and Smads 2, 3 and 4 in granulosa-luteal cells at the time of oocyte retrieval.Methods: Quantitative reverse transcriptase-polymerase chain reaction was performed to quantify the mRNA expression of the investigated genes: inhibin α-subunit, inhibinactivin βA-and βB-subunits, follistatin, and Smads 2, 3 and 4.Results: α-, βA-and βB-subunits of inhibin-activin, and follistatin were all well expressed in granulosa-luteal cells obtained from either dominant or cohort follicles. α-subunits strongly correlated with Smad2 (p < 0.001). βA-subunit significantly correlated with Smad4, p < 0.001. βB-subunit significantly correlated with Smad2, p = 0.002, and follistatin expression strongly correlated with the expression of Smads 2 and 4 (p < 0.001 and = 0.007 respectively).Conclusions: We found, for the first time that inhibinactivin βB-subunit mRNA was well expressed in human granulosa-luteal cells obtained from either dominant or cohort follicles. α-, βA-and βB-subunits and follistatin cor-