Artificial Reproduction Techniques Flashcards
what is ovarian stimulation
- stimulation of ovaries to produce oocytes
- and prevention of premature ovulation
how is ovarian stimulation done
- injections of FSH to increase oocyte production (multiple oocytes at once instead of just one)
- ## start on day 2 of cycle, take onwards
- (still injecting FSH)
- from day 6 onwards
- injections of an antagonist to reduce LH release that triggers ovulation -> delay ovulation
- ## allowing recruitment of multiple oocytes during an IVF cycleie/ making extra eggs using FSH, but not releasing those eggs
- taking both (antagonist from day 6) for up to 2 weeks
[ovarian stimulation] how do we monitor follicles growing in overly stimulated ovaries - utilise 2 ways together
- ultrasound scanning: follicle number and size measured in each ovary
- bloods (hormone levels): oestrogen and progesterone monitored every 2 days from day 8
[ovarian stimulation] what does monitoring the follicles allow us to know and do
- know if patient is ready for oocyte retrieval
what is given for oocyte retrieval
- trigger injection hCG given to release oocytes
(note: hCG detected by LH receptors; used in assisted reproduction to trigger ovulation)
in oocyte retrieval, what monitoring reports are expected to schedule for egg pick up
- once follicles developed to correct size
- bloods corresponding with cycle
- patients scheduled for theatre
in oocyte retrieval, when are eggs collected & how are they collected
- eggs collected 36hrs post hCG
- eggs collected transvaginally with ultrasound guidance
what happens to collected eggs after procedure in oocyte retrieval
- oocytes stored in warming incubator
- mimics their developmental env in vivo
- number of collected oocytes are counted (from the aspirated follicles)
- then oocytes given to IVF lab (if far, transported in incubator)
while oocytes being collected (ovarian stimulation + oocyte retrieval) what other sample needs to be prepared
- sperm sample
what happens at Specialised Andrology facility
- semen sample received and prepared within strict timeframe
- there are different sperm preparation methods
why is sperm sample prepared in a strict timeframe
to ensure best possible sperm quality (mainly sperm concentration, sperm motility)
what do use of varied sperm preparation methods depend on
sperm preparation method based on:
- initial sperm concentration and sperm motility parameters which are measured
- insemination method
[sperm sample preparation] if there is none - little amount of sperm in ejaculate, what can be done?
- Surgical Sperm Retrieval (SSR)
how many types of Surgical Sperm Retrieval (SSR) are there & their names with brief description
3 types
- Testicular Sperm Aspiration (TESA): sperm aspirated from testes
- Percutaneous Epididymal Sperm Aspiration (PESA): sperm aspirated from epididymis
- Testicular Sperm Extraction (TESE / Testicular biopsy): take tissue where sperm can be found from further methods
what are the 2 ways of inseminating eggs
- standard insemination (IVF)
- intracytoplasmic sperm injection (ICSI)
describe standard insemination / IVF method regarding oocytes
- majority of supporting cells (cumulus cells) surrounding oocyte are trimmed from oocytes
- only leaving a few layers around oocyte as still need supporting cells
describe standard insemination / IVF method regarding semen
- sperm sample processed to achieve a certain high motility parameter & diluted to a specific concentration
in standard insemination at what point are oocyte and sperm put together
- 4hrs after oocytes been collected
- prepared sperm placed near oocytes
- in lab
- then these dishes (of fluid mimicking in vivo env) placed back into incubator
what is main insemination method
intracytoplasmic sperm injection (ICSI)
why is intracytoplasmic sperm injection (ICSI) the most common insemination method
- since majority of patients that come in have a semen defect
describe intracytoplasmic sperm injection (ICSI) regarding oocytes
- 3hrs after oocyte collected, lab will remove all cumulus cells from oocyte
describe intracytoplasmic sperm injection (ICSI) regarding sperm
- sperm sample processed to ensure sufficient sperm available
in intracytoplasmic sperm injection (ICSI) at what point are oocyte and sperm put together
- 4hrs after oocytes collected
- egg held in place, one sperm directly injected into egg
- injected eggs placed in dish (of fluid mimicking in vivo env) and placed into incubator
what is embryo selection for transfer based on
is this grading relevant to embyro freezing
- morphology (what it looks like)
- yes, if good enough to transfer then good enough to freeze
what happens during [fresh] embryo transfer
- embryo loaded into very thin catheter by scientist
- placed into uterus (in certain area of thicker part of uterine lining) by clinician under ultrasound guidance
- similar process to papsmear
when would embryo freezing occur
- if patients have more embryos than they are having transferred (ie/ doing both - fresh embryo transfer & embryo freezing of leftover)
- or if they not having embryo transfer - option of freezing
are any embryos frozen?
- no
- only frozen if are of suitable quality
what are embryos frozen in and why
- one embryo per one straw
- frozen into high security straws
- to protect embryo whilst in storage
what happens to embryo in embryo freezing / what is the aim of freezing embyros
- aim is to remove water within embryo (dehydrate it) & replace it with cryoprotectant (antifreeze)
- turning embryo into glass-like state & looks after embryo
- placed into liquid nitrogen and soted
how would you describe the pregnancy rates of frozen embryo transfers to fresh embyro transfers
similar
what day of culture is usually last day for most IVF clinics
- day 6 (after oocyte and sperm been put together)
how long can embryo be stored for after frozen
- as long as you want them
- or as long as its legal timeframe depending on state / country legislation
how is embyro transfer done after embyro freezing
- embyro is thawed
- embyro is rehydrated
- perform as uaul
