Subfertility

Question 1

what is the WHO definition of infertility?

Answer 1

failure to achieve clinical pregnancy after 12 months or more of regular unprotected sexual intercourse (in absence of known reason) in a couple who have never conceived a child

Question 2

where are sertoli cells found?

Answer 2

in the seminiferous tubules of the testes

Question 3

which cell creates the blood testes barrier and what do this barrier do?

Answer 3

sertoli cells
protects the spermatozoa from antibodies and ensures the fluid composition within the testes is suitable for development of the sperm

Question 4

what do the sertoli cells provide for the developing cells?

Answer 4

nutrients, destory defective sperm and remove excess cytoplasm from the seminiferous tubules

Question 5

what do sertoli cells secrete?

Answer 5

seminiferous tubule fluid
androgen binding globulin
inhibin hormone
activin hormone

Question 6

what does seminiferous tubule fluid do?

Answer 6

essential for carrying spermatozoa to epididymis

Question 7

what does androgen binding globulin do?

Answer 7

essential for sperm production (binds testosterone)

Question 8

what do inhibin and activin hormones do?

Answer 8

essential for regulation of FSH secretion and contorl of spermatogenesis

Question 9

where does spermatogensis occur?

Answer 9

inside the seminiferous tubules

Question 10

where are developing sperm stored?

Answer 10

epididymis

Question 11

what is the vas deferens?

Answer 11

a muscular tube that transports te spermatozoe from the epididymis through the spermatic cord, through the inguinal canal, past the bladder and to join the seminal vesicle and forms the ejaculatory duct

Question 12

what is the function of the bulbourethral gland (cowper’s gland)?

Answer 12

produces and releases fluid which lubricates urethra and neutralises any acidity, prior to ejaculation

Question 13

what is the function of the seminal vesicle?

Answer 13

produces and releases majority of seminal fluid containing

• fructose (nourishes sperm cells)
• prostaglandins (triggers contraction of vaginal muscles for sperm motility)
• fibrinogens (clot precursors)

Question 14

what is the function of the prostate gland?

Answer 14

produces and releases

• acid phosphatase
• citric acid
• inositol
• calcium, zinc and magnesium

Question 15

what is the hormonal control of spermatogensis?

Answer 15

• GnRH is released in bursts every 2-3 hours from the hypothalamus
• GnRH stimulates the Ant Pit to release LH and FSH
• LH stimulations testosterone secretion from leydig cells
• testosterone and FSH surges stimulate spermatogenesis with seminiferous tubules
• inhibin released from sertoli cells decreases secretion of FSH and testosterone released from the Leydig cells decreases the release of GnRH adn therefore, decreases LH, providing negative feedback, inhibiting spermatogenesis

Question 16

what is capacitation?

Answer 16

the series of biochemical and electrical events that take place to allow the sperm cell to penetrate the cell layer that surrounds the oocyte, by giving the sperm cell the ability to bind to the zona pellucida via the acrosome reaction

Question 17

why does cystic fibrosis cause male infertility?

Answer 17

• obstruction or absence of the vas deferens bilaterally, known as CBAVD where the VD failed to develop properly

Question 18

what is cryptochidism?

Answer 18

one or both testes being undescended into the dependant part of the scrotal sac

Question 19

what is klinefelter’s syndrome?

Answer 19

47 XXY
genetical male with no extra X chromosome - developmental delays, reduced facial hair, poo muscle tone + gynaecomastia
- infertile

Question 20

what is a robertsonian translocation?

Answer 20

affects the acrocentric chromosomes (13, 14, 15, 21, 22), and can result in extra or missing chromosomes
- increases risk of infertility and miscarriage

Question 21

what is the triad for PCOS?

Answer 21

anovulation
polycystic ovaries
hyperandrogenism (clinical or biochemical)

Question 22

what are uterine polyps?

Answer 22

occur when the endometrial lining inside the uterus overgrows and as a result a polyp forms inside the uterus
- abnormal uterine bleeding
removed by hysterectomy

Question 23

what are uterine fibroids?

Answer 23

benign tumours of the myometrium that can grow in the uterus
main types: subserosal, intramural and submucosal
removed surgically by myomectomy

Question 24

describe intrauterine insemination (IUI)?

Answer 24

directly places the sperm inside the uterus to facilitate fertilisation
only possible when the sperm is healthy, ovulation is taking place and there is no tubal disease

Question 25

when would you use intrauterine insemination (IUI)?

Answer 25

sexual dysfunction (ejaculation dysfunction, erectile dysfucntion, sexual pain disorders) 
female same sex relationships (donor sperm) and male same sex relationships (surrogacy)

Question 26

what are the 4 steps involved in IVF/ ICSI?

Answer 26

1. down regulation
2. ovarian stimulation
3. oocyte collection
4. fertilisation

Question 27

what is in involved in down regulation?

Answer 27

synthetic GnRH analogues are given to ‘shut down’ the natural menstrual cycle, causing a temporary artificial menopause
this enables IVF cycles to be schedules and manages
TVUS carried out to ensure endometrium is thin and ovaries are inactive

Question 28

what is involved in ovarian stimulation?

Answer 28

inducing ovarian follicular development and oocyte maturation, by administering gonadotrophin hormone as an injection
it also helps endometrial wall to thicken in preparation for implantation of the embryo
GnRH agonist is used to prevent LH surges and prevent follicles from releasing the oocyte before it fully matures

Question 29

what is involved in oocyte collection?

Answer 29

it takes place in theatre under US guidance
the needle is inserted transvaginally and the ovarian follicles are aspirated, collecting the oocyte
they’re brought to the embryology lab where the embryologist uses a microscope to identify the oocytes = places in a culture and incubated at 37degrees

Question 30

how does fertilisation occur in IVF?

Answer 30

fertilisation
IVF - sperm places in petri dish with the oocyte = the successful sperm undergo capacitation and fuses with the zona pellucida, eventually the fertilising ovum and creating the zygote

Question 31

what are the indications for IVF?

Answer 31

unexplained fertility (longer than 2 years) 
pelvic disease (tubal disease, endometriosis, fibroids etc) 
anovulatory infertility (after failed ovulation induction

Question 32

how does fertilisation occur in ICSI?

Answer 32

one sperm cell is imobilised and injected directly into the cytoplasm of the oocyte, bypassing stages of the sperm travelling to the ovum, undergoing capacitation, the acrosome reaction and fusing with the ovum

Question 33

what are the indications for ICSI?

Answer 33

severe male factor infertility, previous failed fertilisation with IVF, pre-implantation genetic diagnosis

Question 34

what is surgical sperm aspiration?

Answer 34

used in male fertility with little or no sperm in the semen

Question 35

in surgical sperm aspiration, where the the sperm extracted from?

Answer 35

obstrucitve cause eg CF= epidydmis

non-obstructive = testicular tissue

Question 36

what is stage 5, embryo transfer?

Answer 36

occurs on day 5 (blastocyst stage)
embryo is inserted into the uterus, progesterone suppositories then used for 2 weeks
pregnancy test performed 16 days after oocytre recovery

Question 37

what causes ovarian hyper-stimulation syndrome?

Answer 37

occurs in response to the ovarian stimulation medications given in stage 2 of IVF and ICSI protocols

Question 38

how does ovarian hyper-stimulation syndrome occur and what are the symptoms?

Answer 38

large numbers of growing follicles and high oestradiol levels can lead to release of inflammatory markers and vasoactive substances
these cause fluid shift from within the blood vessels to the 3rd compartment leading to fluid build up in the abdomen
bloating, abdominal distension, nausea and vomiting