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Vitrification of embryos allows IVF clinics to achieve higher success rates
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Dr Aniruddha Malpani, MDDr Anjali Malpani, MD
www.drmalpani.com
Post Thaw
After 6 Hrs Post Thaw
Why freeze embryos?Superovulation = many eggs = many embryos
! What do we do with the spare embryos ?Better to freeze than to discard !
Reduces risk of OHSSImproves pregnancy ratesAdditional option for embryo adoption
( regular adoption becoming much harder these days !)
Principle of freezing embryosStore in liquid nitrogen at - 196 C.
Suspended animation – no metabolic activity
To move the embryo from 37 C to -196 C, we need to use nontoxic cryoprotectants to prevent cold induced damage to the cells , as a result of their exposure to low temperatures
Glycerol, sucrose, ethylene glycol
Slow freezing protocolControlled programmed chillingSurvival rates of about 50%, even in the best
clinicsBlastomere damage because of ice crystal
formationMany embryos did not survive the thaw
Reason for lower pregnancy rate ?The slow freezing and thawing process
damaged and killed a lot of cellsHowever, those embryos which were intact
after freezing and thawing had the same implantation rate as fresh embryos
Need to improve the freezing technologyVitrification = Flash freezing. Rapid
freezing minimizes chilling injury and osmotic shock to the blastomeres
Excellent survivalOnly problem - Steep learning curveSome embryologists who were
proficient at slow freezing found it hard to learn new skills
Vitrification
Teaching tools
Free videos at www.kitazatoindia.com
FreezingCan freeze embryos at any time - from Day 0 –
Day 6It’s useful to freeze only good quality Grade A
embryosPoor quality embryos do not survive the process
well – just provide false hopes !We will freeze even if there is just 1 good quality
blastocystCan freeze for as long as you wantNeed to counsel patients re: what they want to
do with their supernumerary embryosTake informed consent
Many benefits of vitrificationReduce the risk of high order multiple birthsReduces OHSS – we can freeze all embryos,
rather than transfer In the fresh cycle , we need to transfer only
1-2 embryos ( since the rest are being frozen, the patient is not worried that her embryos are being wasted)
Cumulative success rate is very highWe are now doing more frozen transfers in
our clinic than fresh transfers !
Higher success rateParadoxical – but trueReason ? The endometrium is more
receptive in a frozen thaw cycleNot exposed to the
supraphysiological levels of estrogen and progesterone induced by superovulation
Frozen cycleMuch easier for the patient – and for
the clinicMuch less expensive2 options
Natural cycle protocol ( for patients with regular ovulatory cycles)
Endometrial preparation protocol
Natural cycleNo medicationMonitor ovulation ( scans and LH urine
strips)Embryo transfer 48 hours after ovulation,
once the uterine lining is thick and trilaminar
Progesterone supplementation after ET
When to thaw the embryos ?Can thaw on the day of the transfer itselfEasy to make out if the blastomeres are
alive or not. Dead blastomeres are darkSome clinics will thaw 24 hours in advanceWill allow the thawed embryos to cleave in
vitro – this confirms the embryos are viable and helps them to select the best embryos !
Endometrial preparationDownregulation ( with Lupride) is optionalCheck scan on Day 2/3Prepare uterine lining with Progynova
( estradiol valerate, 2 mg)One option - gradually increasing doses every
3 daysWe use 6 mg per day from Day 2 and scan
after 7 daysOnce the lining is trilaminar and more than 8
mm, we start progesterone and do the transfer
Endometrial preparationMay need to increase the Progynova
dosePatients with poor uterine lining can
be difficult to manage !Benefit of frozen cycle – we do not
have to worry about the eggs – can focus purely on improving the endometrium !
Strategies for patients with a poor liningHysteroscopyEndometrial injury ( to improve uterine blood
flow)Bromelain ( enzyme), 200 mg dailyIntrauterine perfusion of recombinant G-CSF
(Granuloyte Colony Stimulating Factor, Filgrastim), active ingredient of Neukine, 300 ug.
Successful treatment of unresponsive thin endometrium. Gleicher, et al. Fertil Steril, Feb 2011
After the transferLuteal phase support with progynova and
progesterone pessaries, 200 mg, thrice a day
Measure progesterone levels after 3 daysShould be more than 10 ng/mlMay need to increase progesterone
supplementation( Try gel or an increased dose)? Injectables ( very painful !)
Kato protocol – world’s busiest IVF clinic !No fresh transfers at all !Electively freeze all embryosTransfer only in the next cycleOnly blastocystsOnly vitrificationThis is now the new gold standard
Need to work towards thisGradual processNeed to master the technical skillsDevelop confidence in your IVF lab !
TrainingMonitoringQuality Control
Doctors cannot afford to be ignorant about what happens in the IVF lab !You do not need to become an embryologist -
but you need to be very knowledgeable !The IVF lab is the heart of the IVF clinic.Treat your embryologist with love and respect
- so he will love and respect your patient’s embryos
Each embryo should be treated as a patient !
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