Principles of infertility

Question 1

What are the types of anatomical causes of infertility in females

Answer 1

Congenital / development
Acquired

Question 2

Give examples of pathophysiological causes of infertility in females

Answer 2

Ovarian pathology:
- Anovulatory anoestrus
- Cystic ovarian disease
- Persistent CL

Uterine infection:
- Pyometra, endometritis, metritis

Failure to establish pregnancy

Question 3

Describe management causes of infertility in females

Answer 3

Nutrition
Oestrus detection
Genetic
Timing/management of mating/AI
Expectation
Stress

Question 4

Give examples of anatomical causes of infertility in females that present at birth/puberty of first breeding

Answer 4

Ovarian hypoplasia (1)
Reproductive dysplasia
Free-martinism / Inter-sex (2,3)
Persistence of hymen (mare) (4)

Question 5

Give examples of acquired anatomical causes of infertility in females

Answer 5

Adhesions (e.g. Ovario-bursal, hydrosalphinx) (5)
Endometrial fibrosis
Cystic endometrial hyperplasia (bitch) (6)
Reproductive tract neoplasia (uncommon)

Question 6

What are the typical presentations of a pathological ovary?

Answer 6

Oestrus not observed (ONO)
Barren/empty at pregnancy diagnosis
Persistent oestrus
Irregular oestrous cycle

Question 7

What are the possible underlying causes of a pathological ovary?

Answer 7

Lack of normal follicular growth / oestradiol1
Lack of GnRH / gonadotrophin
Lack of an LH surge
Lack of endometrial PGF2A production

Question 8

How is a pathological ovary diagnosed?

Answer 8

Hormone analysis i.e. progesterone
Ovarian (uterine) palpation
Ovarian (and uterine) ultrasonography – range of presentation from small, inactive ovaries to gross enlarged follicular structure

Question 9

What are the types of pathological ovary?

Answer 9

Anovulatory oestrus - cow, dog, pig, mare
Cystic ovarian disease - cows, sows
Persistent CL - cows, mares

Question 10

Describe the features of anovulatory anoestrus

Answer 10

Lack of cyclicity
Delayed return post-partum / season
Associated with NEB (-ve energy balance)
After pregnancy failure (mare)

Question 11

Describe the features of cystic ovarian disease

Answer 11

Follicular structure that fail to ovulate and persist
Follicular or Luteal

Question 12

Describe the features of persistent CL

Answer 12

Failure to return to oestrus
CL persists in absence of pregnancy

Question 13

Describe the treatment option for pathological ovary

Answer 13

Promote ovarian function i.e. gonadotrophin via GnRH / ECG
Mimic luteal phase (with progesterone)
Induce luteinisation (ovulation) via GnRH / LH
Induce luteolysis (if luteal tissue is present) - prostaglandin F2A

Question 14

When is repro tract infection/inflammation likely to occur in females?

Answer 14

Ovaritis is very rare
Endometritis, cervicitis, vaginitis common in cows, mares and dogs
Typically presented post-partum (associated with retained fetal membranes, dystocia) or post-mating

Question 15

How does repro tract infection/inflammation cause infertility in females?

Answer 15

Reduced conception / pregnancy establishment
Adverse effects on ovarian function

Question 16

What is the treatment for repro tract infection/inflammation

Answer 16

Stimulation of uterine contractions
Antibiotics

Question 17

Describe the ways in which pregnancy fails to establish

Answer 17

Conception failure:
- inappropriate mating/AI timing
- delayed or lack of ovulation
- chromosomal abnormalities
Early embryonic death:
- poor embryonic development
- failure to secrete maternal recognition signal

Question 18

Describe the nutritional influences on infertility

Answer 18

Specific mineral deficiencies/toxicities:
- Copper
- molybdenum
- Selenium
Management of pregnant / transition animal
Oestrogenic substances in plants
Dietary proteins leading to increased plasma urea

Question 19

Describe second litter syndrome

Answer 19

anovulatory anoestrus:
- still in negative energy balance post-partum
- reduced gonadotrophin/IGF1 levels
- causes weaker, less viable puppies in second litter

Question 20

define fertility

Answer 20

capability of producing offspring

Question 21

define sterility

Answer 21

absolute inability to producing offspring

Question 22

Define subfertility

Answer 22

less than average ability to produce offspring

Question 23

Describe infertility in veterinary medicine

Answer 23

Can be classified using different systems:
- anatomical, physiological, management causes
- obstructive, non-obstructive, coital
- inability to achieve coitus, inability to fertilise

Question 24

Give examples of abnormalities of coitus that may cause in or sub fertility

Answer 24

Immaturity and inexperience
Inability or unwillingness to mount
Inability to achieve intromission
Haemospermia

Question 25

What are possible causes of failure of fertilisation in males

Answer 25

Testicular disease Sperm abnormalities (may be associated with gross testicular or epididymal disease) Epididymal lesions Accessory gland disease (remember not all species have every type of accessory gland)

Question 26

Give examples of reasons for a male to be unable to achieve intromission

Answer 26

Question 27

What is abnormal in this semen sample?

Answer 27

mid piece deviation & some dead sperm