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Glaucia Aparecida Aschenbrenner, Romildo Romualdo Weiss, Tacia Gomes Bergstein-Galan, Fernando Andrade Souza, Natália Santana Siqueira de Lara, Vanessa Balan Julio


Increased rates of embryonic re-expansion and implantation were reported after the use of forskolin during embryo culture, specially due to the reduction of intraplasmatic lipids, which brings improvement to cryopreservation. Thus, the aim of this meta-analysis was to compare the occurance of embryonic re-expansion among different studies that used forskolin on in vitro embryo production, and also match the results. It was considered five articles that assessed forskolin at the 2,5µM, 5,0µM and/or 10µM concentrations on embryo culture, in comparison to the control group (in vitro culture without forskolin). To compare the results of the articles Restricted Maximum Likelihood Method (REML) was applied; to identify the heterogeneity among the studies, the Q test was used, and, to quantify the heterogeneity between the studies I² statistics was employed. Based on the statistics analysis, it is inferred that embryos cultivated with forskolin at a 10µM concentration are 71% more likely to re-expand when compared to the control group, considering 95% confidence interval, between 27% and 132%. There was no statistically significant difference on the chance to suffer embryonic re-expansion when comparing the embryos treated with 5µM concentration forskolin and the control group, leading to the comprehension that 10µM concentration increases the quality of cryopreserved bovine embryos. Despite the results, more experiments are needed.


Delipidation; Cryotolerance; in vitro fertilization.

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ABE, H.; YAMASHITA, S.; SATOH, T.; HOSHI, H. Accumulation of cytoplasmic lipid droplets in bovine embryos and cryotolerance of embryos developed in different culture systems using serum-free or serum-containing media. Molecular Reproduction and Development v.61, p.57–66, 2002. Available from: Accessed: 24/04/2022 doi: 10.1002/mrd.1131. PMID: 11774376.

AKSU, D.A.; AGCA, C.; AKSU, S.; BAGIS, H.; AKKOC, T.; CAPUTCU, A.T.; et al. Gene expression profiles of vitrified in vitro- and in vivo-derived bovine blastocysts. Molecular Reproduction and Development. v.79(9), p.613–25. 2012. Available from: Accessed: 17/08/22. Doi 10.1002/mrd.22068

BORENSTEIN, M.; HEDGES, L.V.; HIGGINS, J.P.; ROTHSTEIN, H.R. Introduction to meta-analysis. New York: John Wiley & Sons; 2009

CARRO, M.; BUSCHIAZZO, J.; RÍOS, G,L.; ORESTI, G.M.; ALBERIO, R.H. Linoleic acid stimulates neutral lipid accumulation in lipid droplets of maturing bovine oocytes. Theriogenology v.79, p.687–94, 2013. Available from: Accessed: 13/02/22 doi: 10.1016/j.theriogenology.2012.11.025. Epub 2012 Dec 27. PMID: 23273433.

CUELLO, C.; GOMIS, J.; ALMIÑANA. C. et al. Effect of MEM vitamins and forskolin on embryo development and vitrification tolerance of in vitro-produced pig embryos. Animal Reproduction Science, v.136(4), p.296–302, 2013. Available from: Accessed: 01/02/22 doi: 10.1016/j.anireprosci.2012.11.003. Epub 2012 Nov 12. PMID: 23238049.

DALCIN, L.; SILVA, R.C.; PAULINI, F.; SILVA, B.D.M.; NEVES, J.P.; LUCCI, C.M. Cytoskeleton structure, pattern of mitochondrial activity and ultrastructure of frozen or vitrified sheep embryos. Cryobiology. v.67(2), p.137–45. 2013. Available from: Accessed: 17/08/22. doi 10.1016/j.cryobiol.2013.05.012

HIGGINS, J.P.T. THOMPSON S G, DEEKS J J, ALTMAN D G. Measuring inconsistency in meta-analyses. BMJ. v.327, p.557, 2003. Accessed: 17/08/22. doi:10.1136/bmj.327.7414.557

HIGGINS, J.; GREEN, S.; EDITORS. Cochrane handbook for systematic reviews of interventions. Version 5.1.0. Oxford: Cochrane Collaboration; 2011. Available from: Accessed: 17/08/22

KARAGENC, L.; SERTKAYA Z.; CIRAY, N.; ULUG, U.; BAHCECI, M. Impact of oxygen concentration on embryonic development of mouse zygotes. Reproductive BioMedicine Online. v.9, p.409-417, 2004. Available from: < > Accessed: 21/02/22. doi: 10.1016/s1472-6483(10)61276-x

MENEGHEL, M.; DALL’ACQUA, P.C.; AMBROGI, M.; LEÃO, C.S.; ROCHA-FRIGONI, N.A.S.; MINGOTI, G.Z. "Lipid Content and Cryotolerance of in Vitro-produced Bovine Embryos Treated with Forskolin before Vitrification." Pesquisa Veterinária Brasileira. v.37.p.4: 395-400, 2017. Available from: < > Accessed: 21/02/22. doi: 10.1590/S0100-736X2017000400015

OLIVEIRA, C.S.; FEUCHARD, V.L.D.S.; MARQUES, S.C.S.; SARAIVA, N.Z. Modulation of lipid metabolism through multiple pathways during oocyte maturation and embryo culture in bovine. Zygote. v.18, p.1-9, 2021. Available from: Accessed: 06/02/22. doi: 10.1017/s0967199421000629

PASCHOAL, D.M.; SUDANO, M.J.; GUASTALI, M.D.; DIAS MAZIERO, R.R.; CROCOMO, L.F.; MAGALHÃES, L.C.; DA SILVA RASCADO, T.; MARTINS, A.; DA CRUZ LANDIM-ALVARENGA, F. Forskolin effect on the cryosurvival of in vitro-produced bovine embryos in the presence or absence of fetal calf serum. Zygote. v.22(2), p.146-57. 2014. Available from: Accessed: 09/03/22. doi: 10.1017/S0967199412000354

PAGE, M.J.; MCKENZIE, J.E.; BOSSUYT, P.M.; BOUTRON, I.; HOFFMANN, T.C.; MULROW, C.D.; ET AL. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. doi: 10.1136/bmj.n71 Online. Available from: Accessed: 17/08/22.

PASCHOAL, D.M.; SUDANO, M.J.; SCHWARZ, K.R.L.; MAZIERO, R.R.D.; GUASTALI, M.D.; CROCOMO, L.F.; MAGALHÃES, L.C.O.; MARTINS, A. JR.; LEAL, C.L.V.; LANDIM-ALVARENGA, F.D.C. Cell apoptosis and lipid content of in vitro-produced, vitrified bovine embryos treated with forskolin. Theriogenology. v.1; p.87:108-114, 2017. Available from: <> Accessed: 03/03/22. doi: 10.1016/j.theriogenology.2016.08.011

PANYABORIBAN, S.; THARASANIT, T.; CHANKITISAKUL, V.; SWANGCHAN-UTHAI, T.; TECHAKUMPHU, M. Treatment with chemical delipidation forskolin prior to cryopreservation improves the survival rates of swamp buffalo (Bubalus bubalis) and bovine (Bos indicus) in vitro produced embryos. Cryobiology. v.84, p.46-51, 2018. Available from: Accessed: 21/02/22. doi: 10.1016/j.cryobiol.2018.08.003.

RODRIGUES, C. & ZIEGELMANN, P. Metanálise: um guia prático. Revista Clinical & Biomedical Research. v.30(4), p.435-446, 2010. Available from: <> Accessed: 20/02/22.

SANCHES, B.V.; MARINHO, L.S.; FILHO, B.D.; PONTES, J.H.; BASSO, A.C.; MEIRINHOS, M.L.; SILVA-SANTOS, K.C.; FERREIRA, C.R.; SENEDA, M.M. Cryosurvival and pregnancy rates after exposure of IVF-derived Bos indicus embryos to forskolin before vitrification. Theriogenology. v.1;80(4), p.372-7, 2013. Available from: <> Accessed: 19/02/22. doi: 10.1016/j.theriogenology.2016.08.011

SEIDEL, G.E. Modifying oocytes and embryos to improve their cryopreservation. Theriogenology, v.65, n.1, p. 228–35, 2006. Available from: < > Accessed: 08/04/22. Doi: 10.1016/j.theriogenology.2005.09.025

SUDANO, M.J.; PASCHOAL, D.M.; RASCADO T.D.S. et al. Lipid content and apoptosis of in vitro-produced bovine embryos as determinants of susceptibility to vitrification. Theriogenology, v.75, n.7, p.1211–20, 2011. Available from: < > Accessed: 04/03/22. doi: 10.1016/j.theriogenology.2010.11.033

SUTTON, A. J.; ABRAMS, K. R.; JONES, D. R.; SHELDON, T. A.; &AMP; SONG, F. Methods for meta-analysis in medical research. 2000.

VIANA, J. Statistics of embryo production and transfer in domestic farm animals. International Embryo Technology Society, v. 36, n. 4, pág. 8-25, 2018. Available from: Accessed: 29/03/22

YIN, H.; SANCHETI, Z.; LIU, E. Cadenas Mitochondrial function in ageing: coordination with signalling and transcriptional pathways J. Physiological. 2015. Available from: <> Accessed: 22/02/22. doi:10.1113/JP270541