Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec 1;19(1):215.
doi: 10.1186/s12978-022-01521-8.

Effect of ovarian growth factors on ultra-structural maturation in frozen human immature oocytes after in vitro maturation: a comparative study

Hakimeh Akbari  1 , Masoud Mohammadi  2
Affiliations

Effect of ovarian growth factors on ultra-structural maturation in frozen human immature oocytes after in vitro maturation: a comparative study

Hakimeh Akbari et al. Reprod Health. .

Abstract

Background: In artificial reproductive technique (ART), nearly 20% of human oocytes are immature in the germinal vesicle (GV) phase. Consequently, the best method for reserving them is cryopreserving GV oocytes, and in vitro maturation (IVM) is recommended. The aim of this study was to determine the ultrastructure characteristics of fresh and vitrified immature human oocytes after in vitro maturation in conditioned mediums.

Methods: This study was a comparative laboratory study carried out in 2018 at Afzalipur Infertility Center in Kerman. 170 fresh and 198 vitrified GV oocytes were cultured within three IVM mediums; α-mem as control medium, α-mem supplemented with human bone marrow mesenchymal stem cells (BM-MSCs) and α-mem supplemented with ovarian growth factors (O.F). After 48 h, the maturation rate and morphological feature of IVM oocytes [132 fresh IVM (fIVM) and 134 vitrified IVM (vIVM)] were evaluated. For the ultrastructure study, 10 IVM oocytes from each medium were compared with 10 fresh in vivo oocytes cancelled from ART.

Results: The survival rate of vitrified GV oocyte after thawing was 88.88%. The oocyte maturation rate was reduced in vIVM compared to the fIVM group (76.33% vs. 77.95%); the highest oocyte maturation rate in the O.F fIVM and lowest in α-mem vIVM (82.35% vs. 71.42%). The lowest number of cortical granules was observed in α-mem vIVM, but the greatest presence of M-SER aggregates was in O.F fIVM. In vIVM oocytes, the oolemma contained irregular little microvillus organization.

Conclusions: The O.F mediums have shown the highest maturation which defends the oocyte ultra-structural conservation.

Keywords: In vitro maturation; Infertility; Oocytes; Ovarian growth factors; Ultrastructure.

Plain language summary

In artificial reproductive technique (ART), nearly 20% of human oocytes are immature in the germinal vesicle (GV) phase. Consequently, the best method for reserving them is cryopreserving GV oocytes, and in vitro maturation (IVM) is recommended. This study was a comparative laboratory study carried out in 2018 at Afzalipur Infertility Center in Kerman. 170 fresh and 198 vitrified GV oocytes were cultured within three IVM mediums; α-mem as the control medium, α-mem supplemented with human bone marrow mesenchymal stem cells (BM-MSCs), and α-mem supplemented with ovarian growth factors (O.F). After 48 h, the maturation rate and morphological features of IVM oocytes were evaluated. For the ultrastructure study, 10 IVM oocytes from each medium were compared with 10 fresh in vivo oocytes cancelled from ART. The survival rate of vitrified GV oocytes after thawing was 88.88%. The oocyte maturation rate was reduced in vIVM compared to the fIVM group (76.33% vs. 77.95%); the highest oocyte maturation rate in the O.F fIVM and lowest in α-mem vIVM (82.35% vs. 71.42%). The lowest number of cortical granules was observed in α-mem vIVM, but the greatest presence of M-SER aggregates was in O.F fIVM. In vIVM oocytes, the oolemma contained irregular little microvillus organization. The O.F mediums have shown the highest maturation with defending the oocyte ultra-structural conservation.

PubMed Disclaimer

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
General fine structure and organelle microtopography are shown by transmission electron microscopy. Control oocyte (a), fIVM α-MEM (b), vIVM α-MEM (c), fIVM B.M (d), Vıvm B.M (e), fIVM O.F (f), vIVM O.F (g). Transmission electron microscopy (TEM) shows the general morphology and organelle microtopography. O oocyte; ZP zonapellucida; m microvilli
Fig. 2
Fig. 2
Ultrastructure of control oocyte (a), fIVM α-MEM (b), vIVM α-MEM (c), fIVM B.M (d), Vıvm B.M (e), fIVM O.F (f), vIVM O.F (g). Round cortical granules with an electron-dense arrival located just underneath the oolemma. The number of cortical granules was reduced in vIVM oocytes rather than f IVM. Note the increased compaction of the inner aspect of the ZP in vIVM groups. Several long Microvilli are seen in the control oocytes (a) and fIVM O.F (f). Also, long microvilli were dispersed on the oolemma of fresh IVM oocytes (b, d, f) rather than in vitrified IVM oocytes (c, e, g), while in the vitrified IVM oocytes, the oolemma was determined to have irregular and little microvillous arrangements. ZP zonapellucida; mv microvilli; CG cortical granules; PVS perivitelline space
Fig. 3
Fig. 3
Control oocyte (a), fIVM α-MEM (b), vIVM α-MEM (c), fIVM B.M (d), Vıvm B.M (e), fIVM O.F (f), vIVM O.F (g). Mitochondria are generally rounded and provided with few peripheral or transverse cristae. Note the presence of complexes between mitochondria and vesicles of SER (arrows). The MV complexes were increased in IVM oocytes; Mitochondria-smooth endoplasmic reticulum (M-SER aggregates) varied in size and shape. SER smooth endoplasmic reticulum; M mitochondria; M-SER Mitochondria-smooth endoplasmic reticulum aggregates
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Argyle CE, Harper JC, Davies MC. Oocyte cryopreservation: where are we now? Hum Reprod Update. 2016;22(4):440–449. doi: 10.1093/humupd/dmw007. - DOI - PubMed
    1. Quaas AM, Pennings G. The current status of oocyte banks: domestic and international perspectives. Fertil Steril. 2018;110(7):1203–1208. doi: 10.1016/j.fertnstert.2018.07.013. - DOI - PubMed
    1. Fasano G, et al. Cryopreservation of human failed maturation oocytes shows that vitrification gives superior outcomes to slow cooling. Cryobiology. 2010;61(3):243–247. doi: 10.1016/j.cryobiol.2010.08.002. - DOI - PubMed
    1. Akbari H. The effect of conditioned media on mouse oocytes ultrastructure following in vitro maturation. Gene Rep. 2020;20:100732. doi: 10.1016/j.genrep.2020.100732. - DOI
    1. Khalili MA, et al. Vitrification of human immature oocytes before and after in vitro maturation: a review. J Assist Reprod Genet. 2017;34(11):1413–1426. doi: 10.1007/s10815-017-1005-4. - DOI - PMC - PubMed

Substances