Is embryo cryopreservation causing macrosomia and what else?
Transcript of Is embryo cryopreservation causing macrosomia and what else?
Is embryo cryopreservation causing
macrosomia – and what else?
Raoul Orvieto M.D.
- Department of Obstetrics and Gynecology,
Chaim Sheba Medical Center, Ramat Gan, Israel
- The Tarnesby-Tarnowski Chair for Family Planning and Fertility
Regulation, Sackler Faculty of Medicine, Tel-Aviv University, Israel.
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No relevant financial relationships
to disclose
Ratio of FET VS fresh cycles RR live birth FET/fresh
Frozen ET
Improvement in Cryopreservation
technology
Transferring fewer embryos
Advantages of Cryopreservation
• Increase cumulative pregnancy rate per cycle
• Facilitate elective single ET
• Prevent late OHSS
• Endometrial pathology / substandard endometrium
• Simplify donor oocyte process
• Fertility preservation
PR/LBR Pregnancy complications
Fresh vs Frozen ET
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FETFresh
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(2019)
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The underlying mechanisms
-----------------------------------------------------ART procedures Maternal factors
COH- high E2
Culture media
The length of time in culture
Manipulation of gametes and embryos
Freezing….
Subfertile women who conceived
without the aid of ART and yet
exhibited an increased risk of
obstetrics complications (Hayashi et al 2012; Marino et al 2014; Zhu et al 2006; 2007).
14Luke et al 2017
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(2019)
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The supraphysiological hormone levels produced by ovarian stimulation in fresh
cycles may affect implantation as well as growth and development of the embryo.
(Imudia et al 2012)
Synchronization between the endometrium and embryos at the time of transfer is
more accurate in frozen cycles and that the uterine environment in frozen cycles
is generally more natural than that following hormonal stimulation of the ovaries
in fresh cycles.
Epigenetic changes during the early embryonic stages as a result of the freezing
and thawing procedures might alter developmental processes and intrauterine
growth potential in FET offspring .Frozen embryos yielding epigenetic patterns
and gene expression more similar to natural conception. (Estill et al 2016; Ghosh et al 2017)
The cause of increased risk of macrosomia and
LGA
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IVF group- mice embryos
resulting from superovulation,
IVF, in vitro culture, and
embryo transfer
Vitrified group- embryos that
were vitrified
Control group- day 14 fetuses
that arose from copulation
Both IVF groups showed loss of methylation in both genes’ DMDs, although a greater loss
was seen in the vitrified group.
This suggests a potential mechanism of vitrification resulting in reversal of the epigenetic
effects of superovulation on the oocyte, with consequentially larger babies.
(2010)
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FET and other pregnancy complications
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Type of endometrial preparation
(2013)
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(2017)
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(2019)
(2019)
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(2019)
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THANK YOU
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