Lecture 13 + 14 ; Infertility and Assisted Reproductive technologies, part 2 Flashcards
What are some ARTs?
Artificial insemination Ovulation induction IVF Cryopreservation Uterus transplantation Ovarian tissue transplantation ICSI
Write some short notes on artificial inseminatation;
- Cheap ($1500) + drugs ($500)
- Might be used for men with low sperm concentration or women with cervical mucous problem
Write some short notes on IUI methodology
Sperm is collected washed and placed directly into the uterus by passing possible cervical blocks
Why would ovulation induction be used in infertility?
Many women who are infertile fail to ovulate
What does ovulation induction do?
Increases the number of follicles produced to be collected for IVF
i.e Clomiphene citrate is used to induce GnRH secretion. Achieved by being an antioestrogen, lowers oestrogen levels, removes negative feedback to the pituitary/hypothalamus, thus FSH/LH secretion
Whats the success of ovulation induction
Approximately 30-50% of infertile women treated with clomiphene will ovulate and become pregnant
Downside; increased twinning rate (1 to 5%) b/c increased double ovulations (fraternal twins)
What are some alternative ovulation induction drugs?
Injected FSH
Leterozole (aromatase inhibitor) reduces estrogen
Whats a problem with ovulation induction?
A problem with ovulation induction particularly when it is used in conjunction with IVF is that naturally occuring gonadotrophins may stimulate early ovulation (thus loss of potential oocytes or multiple pregnancies)
GnRH agonists and antagonists are used to down regulate natural FSH/LH secretion
Whats a condition that can arise from ovulation induction?
Ovarian hyperstimulation syndrome (OHSS)
Endometrium can also become asynchronous with natural cycle while on these drugs
Write some short notes on OHSS
In OHSS capillary permeability is increased such that albumin moves into the extra vascular space and causes colloid osmotic pressure gradient. Thus
- Circulating Hypovolemia
- Abdominal distension with ascites
- Shortness of breath b/c plural effusion
- Severe cases are fatal
Whats a condition that can be treated by drug antagonism?
Hyperprolactemia (prolactinoma, on the pituitary)
- Excess prolactin in blood leads to anovulation
- Treated by bromocriptine, prevents with pituitary release
When was the first IVF baby born?
1978
Describe IVF
Oocytes are removed from the women and incubated in-vitro with sperm.
Once fertilisation has occurred the zygote is then returned to the uterus to implant
How many babies are born in the UK via IVF?
2.2%
Write some short notes on the IVF technique
- Drug induced ovulation
- Invasive surgery to collect many occytes
- Ex vivo culture for several days (system is very sensitive to temperature)
What the consequence of many oocytes being collected?
- The more oocytes collected, the poorer the average quality is
- Question of how many and which ones to return
- Want to avoid multiple pregnancies (4+ can occur some times)
Why are multiple pregnancies bad?
- Multiple pregnancies especially high order pregnancies are not good b/c
- high morbidity due to smaller baby size
- More likely to be delivered earlier
- Require longer time on NICU
Whats the cost of IVF?
$7995 per cycle
2-4k drugs
When it was normal for four embryos to be palced (early ivf) what was the multiple pregnancy rate?
25%
What are the guidelines now to avoid multiple pregnancies?
- Return only two maybe three embryos
- Or selective abortion of foetuses once the pregnancies are clearly established
- or Single Embryo Transfer (SET)
Whats the success rates of IVF?
20-25% not better than natural conception rates
What is cryopreservation?
The cryogenic freezing of tissues, using liquid nitrogen or co2
What can be cryogenically preserved?
Sperm
Oocytes (more difficult than sperm)
Embryos
Why may embryos be cryogenically preserved?
To reduce the number of retrievals in case they want more IVF children
