Infertility and assisted reproductive technologies

Question 1

Reasons for the global decline in fertility rate

Answer 1

increased access to education
lower child mortality
increased cost of raising children
exposure to chemicals/hormones interfering with spermatogenesis
could be differences in counting assays

Question 2

Oligozoospermia

Answer 2

low sperm count
occurs in 1/20 of males
accounts for 1/3 of difficulties

Question 3

Asthenozoospermia

Answer 3

low sperm mobility
sperm movement impeded so they can’t reach egg

Question 4

Teratozoospermia

Answer 4

abnormal sperm
may have an unusual shape
harder to move + fertilise

Question 5

Azoospermia

Answer 5

no sperm

Question 6

Possible problems with sperm production

Answer 6

varicoceles
undescended testes
chromosomal abnormalities
hormonal problems
lifestyle

Question 7

Possible problems with sperm transport

Answer 7

infection
tube blockages
tumours
congenital absence of vas deferens

Question 8

Possible problems with sexual dysfunction

Answer 8

retrograde ejaculation
spinal cord injury
prostate surgery
medicines

Question 9

Fecundity

Answer 9

likelihood of conception
drops between 30-40 and 40-45

Question 10

Varicoceles

Answer 10

most common on left side
when blood flows backwards down internal spermatic vein
causes dilation in vein of testes

Question 11

How does varicoceles cuase infertility?

Answer 11

complex and multifactorial reasons
increases ROS is a key factor

Question 12

Problems with oogenesis + ovulation

Answer 12

age decreased ovarian reserve + decline in quality
hormone imbalances
over/under active thyroid
premature ovarian failure
genetic causes

Question 13

Problems with oocyte/zygote transport and implantation

Answer 13

tubal damage- infection or ectopic pregnancy
endometriosis
fibroids
surgical damage
pelvic inflammatory disease

Question 14

Problems with pregnancy

Answer 14

chromosomal abnormalities
structural issues with uterus
autoimmune condition
lifestyle factors

Question 15

Polycystic ovarian syndrome

Answer 15

most common endocrine disorder in females of reproductive age
associated with absent/irregular menstrual cycles

Question 16

What is PCOS caused by?

Answer 16

imbalance in HPG axis
too much GnRH produced

Question 17

How does increased GnRH cause polycystic ovarian morphology?

Answer 17

increased levels of LH
thecal cells expand + produce androgens but granulosa cells don’t due to lack of FSH in comparison
ovaries become full of half developed oocytes

Question 18

What other effects does PCOS have?

Answer 18

higher testosterone- impacts insulin
hyperinsulinemia
impact on liver enzyme production

Question 19

Diagnosis of infertility in males

Answer 19

semen analysis
then hormone analysis

Question 20

Diagnosis of female infertility

Answer 20

blood hormone analysis

Question 21

Assisted reproductive technologies

Answer 21

used to treat infertility and usually involves treatments where gametes are handled outside the body

Question 22

IVF

Answer 22

in vitro fertilisation
mature eggs removed and fertilised in vitro before reinsertion into uterus

Question 23

IVM

Answer 23

in vivo maturation
oocytes collected at antral phase and cultured in vivo in presence of FSH + other factors

Question 24

ICSI

Answer 24

intra-cytoplasmic sperm injection
sperm/spermatids injected directly into egg cytoplasm

Question 25

CT

Answer 25

cytoplasmic transfer giving infertile women’s oocytes a boost with donor oocytes mixed or heteroplasmic population of mitochondrial DNA banned due to developmental worries

Question 26

GIFT

Answer 26

gamete intra-fallopian transfer eggs+ sperm combined in vitro and immediately inserted into fallopian tube through abdomen incision

Question 27

ZIFT

Answer 27

zygote intra-fallopian transfer same as GIFT but wait until fertilisation occurs

Question 28

NT

Answer 28

nuclear transfer

Question 29

What is the benefit of IVM?

Answer 29

women can avoid use of drugs important if vulnerable to ovarian hyperstimulation syndrome

Question 30

Why does IVF require fertility drugs?

Answer 30

suppression of HPG axis + natural cycle stimulation of oocyte production by ovaries suppression of ovulation also addition of sperm capacitation factors

Question 31

Stages of IVF treatment

Answer 31

ovarian hyperstimulation → egg retrieval → sperm preparation → co-incubation → embryo transfer → pregnancy

Question 32

Benefits of ICSI

Answer 32

bypasses normal fertilisation + allows use of non-motile sperm successful procedure possibility for azoospermic patients if late stage spermatids used instead

Question 33

What are the benefits of GIFT?

Answer 33

fertilisation happens inside the body + embryo transplants naturally can be important for religious reasons

Question 34

Methods of cyropreservation

Answer 34

slow freezing- traditional vitrification- use of high initial cryoprotectants and ultra rapid cooling

Question 35

Ethical and legal considerations for cryopreservation

Answer 35

unclaimed embryos couples breaking up death of partner

Question 36

Mitochondrial transfer

Answer 36

similar to CT aimed at people who have a high risk of passing on debilitating/fatal genetic diseases to their children

Question 37

MT techniques

Answer 37

spindle transfer pronuclear transfer polar body transfer

Question 38

Spindle transfer

Answer 38

metaphase II spindle removed from both of the eggs patient chromosomes are inserted into the egg fertilisation occurs and embryo forms

Question 39

Pronuclear transfer

Answer 39

patients oocytes are fertilised pronulcei are removed + transferred to enculceated egg with normal mitochondria

Question 40

Problems with mitochondrial transfer

Answer 40

mutated mitochondria may gradually increase and reintroduce disease

Question 41

Somatic cell nuclear transfer

Answer 41

similar to mitochondrial transfer no recombination of chromosomes associated with much higher levels of abnormalities/illness

Question 42

Therapeutic cloning

Answer 42

embryo created using SCNT → pluripotent ESCs are harvested from inner cell mass of blastocyst → can differentiate in vitro into specific lineage