Assisted Conception Techniques

Question 1

Describe the menstrual cycle

Answer 1

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

Question 2

Describe the path of the egg

Answer 2

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

Question 3

What is IUI

Answer 3

Intrauterine insemination- sperm is injected directly into the uterus

Question 4

IUI success rate

Answer 4

5-10% - same as natural conception

Question 5

NICE indications for IUI

Answer 5

same sex couple- sperm donation
inability to have sex due to pain or erectile dysfunction etc
male with HIV
mild male infertility, endometriosis, unexplained

Question 6

Steps of natural cycle IUI

Answer 6

ultrasound tracks follicle growth

around day 14 sperm is injected

Question 7

Steps of drug induced IUI

Answer 7

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

Question 8

What is IVF

Answer 8

In vitro fertilisation -stimulate ovaries to produce lots of eggs, harvest eggs, add/mix sperm and insert embryos into uterus for implantation

Question 9

Indications for IVF

Answer 9

tubal disease 
anovulatory disease (PCOS)
unexplained
endometriosis - scarring of tubes, problems with implantation 
PGD

Question 10

Steps for IVF

Answer 10

1. counselling and consent- psychologically ready (success rate)
2. pituitary suppression with GnRH analogues to prevent premature LH surge and ovulation
3. ovarian stimulation with recombinant FSH for multi follicular development
4. HCG triggering creating LH surge
5. egg collection (transvaginal/transabdominal)
6. insemination with sperm
7. embryo culture
8. embryo transfer under ultrasound guidance
9. luteal support-given progesterone as corpus letup isn’t working no too thick endometrium
10. 2 weeks later- pregnancy test

Question 11

What is ICSI

Answer 11

intracytoplasmic sperm injection -problem with sperm fertilising

Question 12

Benefits of using 5-6 day embryo culture over a shorter time frame

Answer 12

allows blastocyst to develop past significant stages-

1. switching on embryonic genome
2. stages of totipotency to differentiation

Question 13

Problems with IIVF

Answer 13

1. multiple pregnancies
2. Ovarian hyperstimulation syndrome (OHSS)
3. needle insertion can cause damage to bladder, bowel, blood vessels and infection
4. congenital abnormalities and long term maternal risk
5. very expensive
6. very invasive

Question 14

OHSS

Answer 14

ovarian hyperstimulation syndrome- too much FSH can cause over stimulation can cause system VC, ascites, oedema

Question 15

PGD

Answer 15

pre-implantation genetic diagnosis

cystic fibrosis, huntingtons, sickle cell, DMD

Question 16

PAS

Answer 16

pre-implantation aneuploidy screening

Question 17

Ethical arguments against IVF

Answer 17

same sex couples- no fertility problem so no funding
sex selection
couple splitting up before embryo transfer
fate of other embryos
should IVF be NHS funded
PGD- designer babies?