Assisted Conception Techniques Flashcards
Describe the menstrual cycle
Day 1- start of gradual increase in FSH driving follicular development. With this development, granulose cells form and secrete oestrogen lowering LH and FSH through negative feedback.
Day 12- oestrogen peaks, above the threshold so LH surge due to positive feedback.
36h after LH surge ovulation occurs and follicle becomes corpus luteum secreting progesterone (start of luteal phase) causing endometrium to be receptive to embryonic implantation.
Oestrogen + progesterone high = low LH and FSH
No fertilisation then corpus luteum degenerates so low oestrogen and progesterone = high LH and FSH so endometrium sheds
Describe the path of the egg
Day 1- released from ovary into uterine tube
Day 2/3- egg moves through uterine tube to be fertilised in ampulla
Day 4/5- blastocyst moves into uterine cavity
Day 5/6- blastocysts implants into wall
What is IUI
Intrauterine insemination- sperm is injected directly into the uterus
IUI success rate
5-10% - same as natural conception
NICE indications for IUI
same sex couple- sperm donation
inability to have sex due to pain or erectile dysfunction etc
male with HIV
mild male infertility, endometriosis, unexplained
Steps of natural cycle IUI
ultrasound tracks follicle growth
around day 14 sperm is injected
Steps of drug induced IUI
given GnRH analogies to suppress natural oestrogen so FSH is high to increase the no. of mature follicles. HCG trigger given to tiger ovulation as mimics the LH surge
What is IVF
In vitro fertilisation -stimulate ovaries to produce lots of eggs, harvest eggs, add/mix sperm and insert embryos into uterus for implantation
Indications for IVF
tubal disease anovulatory disease (PCOS) unexplained endometriosis - scarring of tubes, problems with implantation PGD
Steps for IVF
- counselling and consent- psychologically ready (success rate)
- pituitary suppression with GnRH analogues to prevent premature LH surge and ovulation
- ovarian stimulation with recombinant FSH for multi follicular development
- HCG triggering creating LH surge
- egg collection (transvaginal/transabdominal)
- insemination with sperm
- embryo culture
- embryo transfer under ultrasound guidance
- luteal support-given progesterone as corpus letup isn’t working no too thick endometrium
- 2 weeks later- pregnancy test
What is ICSI
intracytoplasmic sperm injection -problem with sperm fertilising
Benefits of using 5-6 day embryo culture over a shorter time frame
allows blastocyst to develop past significant stages-
- switching on embryonic genome
- stages of totipotency to differentiation
Problems with IIVF
- multiple pregnancies
- Ovarian hyperstimulation syndrome (OHSS)
- needle insertion can cause damage to bladder, bowel, blood vessels and infection
- congenital abnormalities and long term maternal risk
- very expensive
- very invasive
OHSS
ovarian hyperstimulation syndrome- too much FSH can cause over stimulation can cause system VC, ascites, oedema
PGD
pre-implantation genetic diagnosis
cystic fibrosis, huntingtons, sickle cell, DMD