Subfertility and assisted Conception Flashcards
Definition of fecundity
The chance of conception for a couple over 1 month
Average fecundity for a couple under 32 y/o
20% per month
Statistics for rates of natural conception
20% of couples will conceive within 1 month
80% within 1 year
86% within 2 years
90% within 3 years
When do you begin to investigate subfertility
In all couples after 1 year of failing to conceive
Earlier should be offered to higher risk couples:
- women older than 35y
- history suggestive of anovulation, tubal disease or male factor problems
How common are male factor problems in fertility, what is the main cause
5% of men are subfertile
85% of these have suboptimal semen quality
Topics of causes of infertility
Oocytes: ovulation, ovarian reserve, timing of sexual intercourse Tubal factors (patency) Other female factors: abnormal uterine anatomy Male factors: suboptimal sperm, azoospermia, coital dysfunction, immune factors
Causes for anovulation/impaired ovulation
HPO axis disruption:
- BMI higher than 29 or less than 19
- PCOS (most common cause)
- Hyper- or hypothryroidism
- Hyperprolactinaemia
Cycle of ovulation
Primordial follicles - Pre-antral (primary) follicles - secondary follicles (oocyte + granulosa cells) - antral follicles (zonal pellucida) - dominant follicle - Ovulation - Corpus luteum development
Spermatogenesis cycle
Begins at puberty and continues throughout life
74 days to produce sperm
10 days to travel to head of epididymis
70% of mature sperm stored in head
Ejaculation - passage of sperm through vas deferens into urethra adjacent to prostate
7 day lifespan in uterus
What is azoospermia
Absence of MOTILE sperm in semen
Causes of fallopian tube obstruction
Previous pelvic inflammatory disease (e.g. chlamydia)
As a result of any inflammatory process in abdomen/pelvis ( surgery, endometriosis, IBD - all cause adhesions)
Causes of unsuccessful implantation
Abnormal endometrium:
- Fibroids
- Uterine adhesions (Asherman’s syndrome)
- Uterine polyps
Cycle of oocytes in female lifetime
highest number in 2nd trimester of pregnancy in a female foetus
Sharp decrease during third trimester
Progressive decline in number of oocytes after birth
Complete depletion at menopause
Pre-conception advice
Stop smoking Moderate alcohol (no binges) Avoid drugs (especially cones) Moderate exercise Optimise BMI Avoid occupational exposures Female: folic acid, vitamin B6 & B12, omega 3 Males: Vitamin E, selenium
Optimal timing of intercourse for conception
few days before ovulation to a few days after (ovulation always occurs 14 days before start of period)
How to tell when ovulating
Clear endocervical mucous (spinbarket - stringy and pliable)
Ferning on slide
Basal body temperature rises
Investigations of ovulation
Day 21 progesterone - rises in response to ovulation
Basal body temperature - rises in response to progesterone
LH kits - detect LH surge prior to ovulation
Cycle tracking - measure of oestrogen, progesterone and LH throughout cycle, performed by fertility specialist, can determine when ovulation has occurred
Investigating ovarian reserve
Relatively new, specialist test
“Egg timer test”
- perform on day 3-5 of cycle
- FSH, AMH and US of ovarian volume and antral follicle count
high FSH and low AMH indicates low reserve
Age-based test - compare to likely parameters at that age
History required when assessing sperm-related factors of subfertility
Fathered other pregnancies
Congenital issues (e.g. cryptorchidism)
Previous surgery/trauma/hernias/torsion
Infections (mumps orchitis, STIs - obstructed vas)
Other illnesses (cancer, CTx, CF)
Smoking, drinking, drugs
Occupational exposures (Solvents, radiation, mining chemicals)
When to perform semen analysis
3-4 days after sexual abstinence
2 abnormal results required to diagnose male subfertility
Normal parameters for semen analysis
Volume more than 2mL pH more than 7.2 Sperm conc more than 20M/mL total sperm count more than 40M/ejaculate Motility more than 50% grade a and b Morphology more than 30% normal forms
Tests indicated if low sperm count or azoospermia
testosterone levels
LH and FSH
screen for CF gene (congenital bilateral absence of vas deferens)
Most common causes for subfertility and how common are they
Ovulatory dysfunction 30% Tubal Pathology 15% Male factor 20% Unknown cause 20% Endometriosis 7% Uterine causes 3% Cervical causes 2% Multiple causes 3%
How common is subfertility
Affects 1 in 7 couples