Assisted Conception

Question 1

Define hypogonadotropic hypogonadism or secondary hypogonadism

Answer 1

A clinical syndrome that results from gonadal failure due to abnormal pituitary gonadotropin levels.
HH may result from either absent or inadequate hypothalamic GnRH secretion or failure of pituitary gonadotropin secretion

Question 2

Mechanism of action and indication for Clomifene citrate

Answer 2

• Selective oestrogen receptor modulator
• Blocks the negative feedback effect of oestrogen on FSH
• Resulting in increased levels of FSH
• First line for PCOS

Question 3

Discuss ways to measure ovarian reserve

Answer 3

• Early follicular FSH (inter cycle variability- not the best test)
• Antral follicule count
• AMH (secreted by granulose cells)
• Response achieved by first round of ART cycle may be best predictor of ovarian reserve

Question 4

Discuss indications for surgical sperm removal

Answer 4

Obstructive Azoospermia
Ejaculatory problems
Spinal cord injuries if electro-ejaculation fails

Question 5

Describe the rationale behind injectable Gonadotropins during an IVF cycle

Answer 5

• Concept of extending FSH window
• FSH remains above threshold required to stimulate follicle growth
• Addition of exogenous FSH overrides the negative feedback effects of increasing oestrogen on the system
• Allows multiple follicles to mature to dominance
• Rescue of smaller follicles that would have otherwise undergone atresia

Question 6

Describe the protocol advised and the rationale behind this for women with high ovarian reserve

Answer 6

• Short protocol (GnRH agonist used as trigger)
• In short protocol GnRH antagonist is used to prevent ovulation early
• GnRH agonist used to trigger ovulation at a controlled time
• This is used to reduce the risk of ovarian hyperstimulation syndrome
• As hCG has a longer half life and greater binding affinity than LH

Question 7

Describe how and why sperm undergo capacitation

Answer 7

o Capacitation is required to render sperm competent to fertilize an oocyte
o The uterus aids the steps in capacitation by secreting sterol-binding albumin, lipoproteins and proteolytic and glycosidic enzymes such as heparin
o Allows sperm to penetrate outer layer of the egg
o The changes are facilitated by removal of glycoproteins resulting in increased membrane permeability to Ca2+
o Influx of Ca2+ leads to inc. cAMP and thus increased sperm motility
o Only capacitated sperm can pass through the corona cells and undergo the acrosome reaction

Question 8

Describe the role of the acrosome reaction

Answer 8

o The acrosome reaction allows sperm to penetrate oocyte coat
o Penetration of the corona radiata by releasing hyaluronidase from acrosome reaction to digest cumulus cells surrounding oocyte, acrosin digests zona pellucida membrane

Question 9

Discuss the prevalence of infertility and chances of pregnancy in natural conception

Answer 9

In the general population up to 90% of couples will have conceived after regular unprotected intercourse for 3 years

• 84% of couples conceive within 1 year
• Of the remainder 50% conceive in the second year (cumulative pregnancy rate over 90%)
• Around 1/7 couples are infertile (15%)
• 50% conceive spontaneously with appropriate advice