LECTURE 30 - infertility Flashcards
What are the requirements for fertility?
- production of normal sperm (maturation)
- production of normal eggs
- sperm traverse the female tract to reach egg - capacitation must occur within time constraints
- sperm penetrate and fertilise the oocyte
- implantation of embryo into uterus
What is the clinical definition of infertility?
Failure to conceive after regular unprotected sexual intercourse for 2 years in the absence of known reproductive pathology
What are the main female factors that cause infertility?
- Ovulatory disorders (~60%)
- Disorders of the female tract
- Implantation, growth and development (during pregnancy)
What is tubal obstruction?
- one of the most common disorders of the female tract
- usually secondary consequence of pelvic infection (blocks uterine tubes)
- increased incidence after STIs
- scarring and adhesions in uterine tubes –> impaired oocyte and sperm transport
- diagnosed by HysteroSalpingoGram (HSG), Hystero Contrast Sonogarphy (HyCoSy) or laparoscopy
What is endometriosis?
- endometrial tissue growth in ectopic sites; uterine tubes, ovary or peritoneal cavity –> scarring/ adhesions
What is a separate or bicornuate uterus?
- type of uterine abnormality
- congenital anomaly
- divided uterus
- uterus may be partial or incomplete
- can cause miscarriage, pre-term birth, malpresentation
- can be surgically removed or wait and have C-section
What are uterine leiomyomas (fibroids)?
- affects 1/3 people
- benign smooth muscle tumours driven by oestrogen (as more common in obese people and during menopause they normally leave)
- develop within uterine wall
- can lead to menorrhagia, subfertility, miscarriage
- treated with hormone therapy or surgery
What can occur in males to cause infertility?
- Production of spermatozoa
- Transport of spermatozoa through male tract
- Transmission of sperm to the female
- Sperm function in the female tract
How are male problems with infertility diagnosed?
- most through semen analysis
- a few violent bloody analysis (testosterone, FSH/LH)
- genetic screening
- many cannot be diagnosed
What can be deduced from semen analysis?
- Normozoospermic = >15 million spermatozoa/ml, >32% rapid forward progressive motility, >4% normal morphology
- Oligozoospermic = <15 million spermatozoa/ml
- Asthenozoospermic = <32% progressive motility
- Teratozoospermic = <4% spermatozoa with normal morphology
- Azoospermic = no sperm in ejaculate
How can issues with production of spermatozoa arise?
Genetic = Y chromosome deletions (10% of men presenting with severe oligozoospermic or azoospermic)
Cryptorchidism (1/100) = failure of testes to descend, reduced spermatogenesis and increased risk of testicular cancer
Acquired = trauma, orchitis (mumps), lifestyle (e.g. alcohol/smoking)
How can failure in transport in male tract occur?
- Azoospermic semen can have 2 causes, obstructive (something stopping sperm going from testes to ejaculate) or non-obstructive (doesn’t produce any sperm)
Can occur from
- post infection (bilateral epididymal/ vas occlusion)
- congenital bilateral absence of vas deferens (CBAVD)
What is CBAVD?
Congenital Bilateral Absence of Vas Deferens
- improper development of vas deferens
- linked to CFTR gene mutations
- > 95% of men with CF have CBAVD
- 85% of men with CBAVD are heterozygous for CFTR mutation - no or mild symptoms of CF
What issues can arise in failure in transmission in males?
- erectile dysfunction (1/10 men)
- ejaculatory dysfunction (retrograde ejaculation or defects of accessory sex glands that produce seminal plasma)
What happens in normal ejaculation and what is retrograde ejaculation?
Normally
- contraction of musculature of prostate, seminal vesicles and vas deferens –> seminal fluid and sperm –> urethra = emission
- contraction of urethral and pelvic floor musculature –> ejaculation
- urethral sphincter closes bladder neck
Retrograde
- incompetence of urethral sphincter
- ejaculation into bladder
- ejaculate volume nil or low
- confirmation in urine
