EAST 501 Lecture Notes - Lecture 9: Ethylene Glycol, Fertility Preservation, Female Infertility
21 Jun 2018
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Jan 26th – Lec 8 Fittzharris
Female infertility: Ovarian aging and aneuploidy
- number of oocytes in cortex decreases with time.
- freezing an embryo is relatively easy clinics are pretty good at this
- taking pieces of ovary and freezing it and putting it back into the mom is very difficult
- age of childbirth has been increasing across the decades
- female fertility preservation broken down into 3 broad approaches: easiest hardest (“do-ability”)
orecovering ovary
oimmature (GV) oocytes
omature (MetII) oocytes, and fertilised embryos
- start with “easiest” part of preservation: Mature eggs and Embryos
oIn what circumstances might this be employed? (What type of patient might opt for this
general type of treatment?) in order to freeze an embryo, you need to do IVF and super-
ovulate the patient
Delay motherhood “waiting until career is established”
Adult females about to have chemotherapy (early 20’s chemotherapeutic patients)
Repeat attempt fertility patients (patients who have undergone IVF already and had a
lot of oocytes collected and fertilized can save these other embryos for a 2nd child)
NOT FOR:
children about to undergo therapy not useful for pre-pubertal girls who won’t
be affected by IVF for the collection of the oocytes
women with hormone sensitive cancers
women with extremely aggressive (time sensitive) cancers
- take oocyte and mix with sperm grow embryo to the blastocyst stage transfer into mom
oif it is to be frozen, do all steps up until the transfer
- Egg vs. embryo – which to store?
oEgg:
good for “keeping you options open:
and is the legal property of the women
oEmbryo:
best in terms of ease of treatment and likelihood of good outcome
good if in stable relationship, or don’t mind suing donated sperm
oit is easier to freeze and thaw embryos compared to eggs
SLOW FREEZING
- Oocyte and embryo (slow) freezing – how does it work?
oput cryoprotectants in
ogradual slow cooling between minus 5 and 30C
oput ice around the embryos H2O diffuses out osmotic pressure increases
Medium outside oocyte has increased molarity and this causes the oocyte to shrink
because water is being sucked out. You don’t want ice crystals inside the oocyte
olong term storage in liquid nitrogen – before thawing
- tiny amounts DMSO and ethylene glycol are used for oocyte and embryo slow freezing
- been used for many years with embryos with good success
- far less successful in oocytes
owhy? smaller cells
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
In order to freeze an embryo, you need to do ivf and super- ovulate the patient. Delay motherhood waiting until career is established . Adult females about to have chemotherapy (early 20"s chemotherapeutic patients) Repeat attempt fertility patients (patients who have undergone ivf already and had a lot of oocytes collected and fertilized can save these other embryos for a 2nd child) Not for: children about to undergo therapy not useful for pre-pubertal girls who won"t be affected by ivf for the collection of the oocytes. Women with extremely aggressive (time sensitive) cancers take oocyte and mix with sperm grow embryo to the blastocyst stage transfer into mom: if it is to be frozen, do all steps up until the transfer. Egg vs. embryo which to store: egg: good for keeping you options open: and is the legal property of the women, embryo:
