Infertility Flashcards
What proportion of couples are affected by infertility at some point in their lives?
1 in 6
What is the World Health Organisation definition of infertility?
inability of couple to achieve clinical pregnancy within 12 months of beginning regular unprotected sexual intercourse
What are 2 types of infertility?
- Primary infertility
- Secondary infertility
What is primary infertility?
No previous pregnancies within the relationship
What is secondary infertility?
Couple has had at least one pregnancy in the past
What proportion of the normal fertile population will conceive within 1 year, and what proportion by the end of 2 years?
84% by end of 1 year, 92% by end of 2 years
What are the terms used to express the chance of conception within a given time interval?
- Cumulative pregnancy rates
- Live birth rates
Chance of realising a family with one child with + without IVF with advancing maternal age in image
What is the definition of fecundability?
percentage of women exposed to the risk of a pregnancy for one menstrual cycle, who will subsequently produce a live-born infant
What is the normal range of fecundability for one menstrual cycle?
15-28%
What is the trend of fecundability over time?
usually diminishes slightly with each passing month of not conceiving
What single factor causes fertility to decline?
age
What is the rough number of oocytes a woman is born with?
1 million
By puberty how many oocytes does the average woman have?
approximately 250 000
How many oocytes does the average woman have by menopause?
below 1000
How many mature oocytes will a woman typically release during her life?
only 500
What happens to the remaining oocytes that are lost throughout a woman’s life, that are not released as a mature oocyte?
undergo atresia or apoptosis
How many functioning oocytes remain at the menopause (average age 51 years)?
no functioning oocytes
What causes the decline in fertility with increasing age?
directly related to declining oocyte population and the eggs’ inherent quality
increased risk of miscarriage with advancing maternal age
From what age does a very steep decline in fecundity occur?
from age 40 (but small declines from 31 and 36 also)
How does the effect of male age on fertility compare with female?
effect of age on men’s fertility is less pronounced
What are 5 groups of causes of infertility?
- Ovuation disorders
- Male factor
- Unexplained
- Tubal factors
- Others including endometriosis
What are 6 things to look for during examination of a woman for infertility and why for each?
- Heigh and weight for BMI: high or low associated with lower fertility
- Body hair distribution: hyperandrogenism
- Galactorrhoea: hyperprolactinaemia
- Uterine structural abnormalities: may be assoc/ w infertility
- Immobile and/or tender uterus: endometriosis or PID, assoc/ w tubal damage
- Visual fields: pituitary adenoma causing hyperprolactinaemia
What is the easiest way to determine uterine structural abnormalities?
most usefully determined by transvaginal ultrasound
What are 4 things to look for in the examination of a man in infertility?
- Scrotum - varicocele/ swellings
- Size (volume) of testes - small testes associated with oligospermia
- Position of the testes - undescended testes
- Prostate - chronic infection
- Outline of epididymis - for presence of vas deferens
What is the range for normal BMI?
19-25
What type of change in weight can cause anovulation/menstrual disturbance leading to infertility?
Change in weight of >10%
What is the commonest cause of hyperandrogenism?
PCOS
When should examination of the man be performed in infertility?
only in presence of any relevant history
or genitalia examination if semen analysis abnormal
What are 5 initial investigations which you might perform to investigate infertility?
- F: early follicular phase (e.g. day 2) luteinising hormone (LH), follicle-stimulating hormone (FSH), oestradiol, anti-Müllerian hormone (AMH)
- F: rubella (offer vaccination if not immune)
- F: Day 21 (7 days before menses) serum progesterone (to assess ovulation)
- F: test of tubal patency (laparoscopic hydrotubation, hysterosalpingo-contrast sonography (HyCoSy) or hysterosalpingography (HSG)
- M: semen analysis x1
What are 4 early follicular phase hormones to measure in the female for initial investigations for infertility?
- LH
- FSH
- Oestradiol
- Anti-Müllerian hormone (AMH)
What are 5 investigations to be selectively performed to investigate female infertility?
- Pelvic ultrasound scan for ovarian morphology and uterine abnormalities
- Laparoscopy for diagnosis of endometriosis, may be combined with tubal patency
- Hysteroscopy for intrauterine anomalies
- Prolactin and thyroid function tests
- Testosterone, androstenedione, 17-hydroyprogesterone and sex hormone-binding globulin (SHBG, to calculate Free Androgen Index, when raised is an indicator of hyperandrogenism)
What are 4 types of hormones which may be selectively measured, and are usually performed together, when investigating female infertility?
- Testosterone
- Androstenedione
- 17-hydroxyprogesterone
- Sex hormone-binding globulin (SHBG)
What are 4 investigations for male infertility to be selectively performed, in addition to semen analysis?
- Sperm function tests if initial test consistently abnormal
- Mixed agglutination reaction test or immunobead test for antisperm antibodies
- FSH, LH, testosterone if low sperm count (oligospermia) (raised FSH if testicular failure, low if central nervous system cause)
- Transrectal ultrasound for suspected abnormalities of the seminal vesicles and prostate
What are 3 ways to classify male factors for infertility?
- Sperm production
- Sperm function
- Sperm delivery
What words are used to desribe absent sperm production?
azoospermia
What is the term for a reduced count of sperm of normal appearance?
oligospermia
What is the word used to describe poor sperm motility, lacking the normal forward progressive movement?
Asthenospermia
What is the word for sperm which appear morphologically defective with abnormalities of head, midpiece or tail?
teratospermia
Overall what are 4 examples of disorders of sperm production?
- Azoospermia
- Oligospermia
- Asthenospermia
- Teratospermia
What can cause azoospermia?
Testicular failure
What is meant by normal sperm function?
ability of sperm to reach, bind and fertilise the oocyte
What methods are available to measure sperm function?
no reliable methods currently available other than monitoring proportion of sperm moving and assessing speed of their progress
What factor can affect sperm motility?
antisperm antibodies
What are 4 causes of problems with sperm delivery?
- Absence or blockage of vas deferens or epididymis
- Impotence
- Premature ejaculation
- Physical inability to have normal sexual intercourse
To summarise what are the 3 types of male factors of infertility and examples of causes?
- Sperm prodcution: azoospermia, oligospermia, asthenospermia, teratospermia
- Sperm function: antisperm antibodies
- Sperm delivery: absent/blocked vas/epididymis, impotence, premature ejaculation
What information does semen analysis provide about sperm?
spermatogenesis (production) and aspect of sperm delivery, but gives little information about sperm function
What are the 6 parameters that are measured by semen analysis?
- Volume
- Concentration
- Total motility
- Progressive motility
- Normal forms
- Vitality
What is the lower limit of reference range for 1. sperm volume 2. concentration 3. total motility 4. progressive motility 5. normal forms 6. vitality?
- Volume: 1.5ml
- Concentration: 15 x 106 / ml
- Total motility: 40%
- Progressive motility: 32%
- Normal forms: 4%
- Vitality: 58%
What should be done when a man’s sperm count is found to be abnormal?
second count should be arranged, as individual man’s result varies considerably- should be at least 3 months apart as spermatogenesis takes approximately 3 months to complete
What time should there be in between sperm samples and why?
3 months, as spermatogenesis takes approximately 3 months to complete
How should sperm samples for semen analysis be taken?
Masturbation or sexual intercourse into non-lubricated condom
What period of abstinence is required prior to obtaining a sperm sample for semen analysis?
between 3 and 5 days prior
How commonly are tests of sperm function performed?
no longer used routinely, more emphasis now placed on identification of number of abnormal/normal sperm
some sperm function tests, such as ability of sperm to swim through culture medium, employed in specialised reproductive medicine units where more complicated treatment may be considered
What are 3 examples of tests of sperm function?
- Ability of sperm to swim through culture medium
- Post-coital test
- Antibodies against sperm
What is the post-coital test of sperm function?
involves asking the couple to have sexual intercourse timed to the woman’s mid-cycle
6-12 hours later sample of endocervical mucus is taken, looking for presence or absence of sperm
Why is the post-coital test sometimes considered for testing sperm function?
some studies show positive correlation between finding of motile sperm in mucus and chance of subsequent pregnancy
Why have most centres abandoned the post-coital test of sperm function?
some studies show finding positive or negative result doesn’t alter chance or timing of pregnancy
What can cause antibodies to develop against sperm and what is the commonest cause?
- injury or infection to the testis and epididymis
- Vasectomy and attempted reversal are commonest
What types of antibodies can form against sperm and how do they attach to them?
- serum IgA or bound IgA
- Attach principally to tail, midpiece or head of sperm
What are 2 examples of the tests used to identify antisperm antibodies?
- Mixed agglutination reaction test
- Immunobead test
What levels of antisperm antibodies detected are thoguht to affect fertility?
- 17-49%: likely to be associated with fall in fertility
- >50%: significantly affect fertility
What are 2 key things which ovarian failure may be associated and what proportion of these conditions are associated with ovarian failure?
- Primary amenorrhoea: 50% have ovarian failure
- Secondary amenorrhoea: 15%
What are 2 examples of causes of primary amenorrhoea, which may be associated with infertility (50% of time)?
- Genetic causes e.g. Turner syndrome (45, XO)
- Autoimmune
What are 3 examples of causes of secondary amenorrhoea, 15% of which may present with infertility?
- Previous ovarian surgery
- Abdominal radiotherapy
- Chemotherapy
What is the term given to ovarian failure with no identifiable cause?
Idiopathic premature menopause
What are 4 key causes of anovulation as a cause of female fertility?
- Weight-related anovulation
- Polcystic ovary syndrome
- Luteinised unruptured follicle syndrome
- Hyperprolactinaemia
What degree of body fat is considered needed to maintain ovulatory cycles?
minimum 22% of body weight
How does substantial weight loss affect ovulation?
- leads to disappearance of normal 24h secretory pattern of gonadotrophin-releasing hormone (GnRH) which reverts to nocturnal pattern seen in pubescent girls
- Ovaries develop multifollicular appearance on ultrasound
What will the appearance of ovaries on ultrasound be in weight-related anovluation due to weight loss?
multifollicular appearance
How can excessive exercise cause anovulation?
increases muscle bulk and decreases body fat
(female athletes or ballerinas can be amenorrhoeic)
How does excess weight gain affect fertility?
profound effect:
reduces chance of conception, increases risk of miscarriage and risk of obstetric complications
What is the effect of distribution of weight on fertility?
central (visceral) fat has bigger impact on fertility than peripheral fat distribution
waist-hip ratio, which more reliably picks up visceral fat distribution, is a more reliable guide to impact of fat on fertility than the BMI
What proportion of women presenting with anovulatory infertility will have PCOS?
50%
What is luteinised unruptured follicle syndrome?
oocyte may be retained following luteinising hormone (LH) surge
What will repeated ultrasound scans show in luteinised unruptured follicle syndrome?
will fail to show expected collapse of follicle at ovulation, and follicle persists into the luteal phase
In what proportion of cases of secondary amenorrhoea is hyperprolactinaemia diagnosed?
10-15%
What proportion of women with hyperprolactinaemia will have galactorrhoea?
one third
What are 2 key symptoms of hyperprolactinaemia?
- Galactorrhoea
- Visual impairment (bitemporal hemianopia) due to pressure on optic chiasm from pituitary adenoma
What are 2 types of investigations of ovarian function that can be performed?
- Tests of ovulation
- Tests of ovarian reserve
What is the only way to categorically confirm ovulation?
pregnancy
What are 3 investigations to perform that can imply that ovulation has taken place?
- History: over 90% of women with regular menstrual cycles will ovulate spontaneously
- Urinary LH kit: picks up mid-cycle surge of LH that start cascade reaction leading to ovulation
- Mid-luteal phase progesterone (7 days prior to first day of period)
What is the most commonly used test of ovulation?
Mid-luteal phase progesterone
What is the level of mid-luteal phase progesterone generally regarded as evidence of satisfactory ovulation?
>28 nmol/L
When should the mid-luteal phase progesterone test be timed for?
between 7 and 10 days before next menstrual period (need knowledge of length of patient’s normal cycle)
What is the definition of ovarian reserve?
number of viable oocytes in the ovary
When is testing ovarian reserve particularly important?
women contemplating more complex fertility treatment - may provide guide to their response to treatment
What are 4 ways to test ovarian reserve?
- FSH at start of menstrual cycle (early follicular phase)
- Antral follicle count on ultrasound - number of small developing follicles seen in ovary
- Measuring ovarian volume
- Measuring concentration of anti-Müllerian homrone (AMH)
When should FSH be measured to determine ovarian reserve?
between days 2 and 5 of menstrual cycle
How is the result of early follicular phase FSH interpreted for ovarian reserve?
raised FSH between days 2-5 indicates impaired ovarian reserve and likely poor response to ovarian stimulation
Why can ovarian volume be measured as a way of determining ovarian reserve?
indication of ovarian activity as ovaries decrease in size with advancing age and decline in oocyte number s
What is AMH and why is it measured for determining ovarian reserve?
- produced in small developing follicles
- unlike FSH can be usefully measured throughout menstrual cycle
What is the key benefit of tests of ovarian reserve?
identifying women who may not respond well to fertility treatment or will have shorter reproductive lifespan (not great for predicting overall natural fertility if woman has regular menstrual cycle and is ovulating)
In addition to tests of ovulation and of ovarian reserve, what are 4 further types of investigations for infertility that may be considered in women?
- Pelvic ultrasound
- Chlamydia serology
- Serum testosterone measurement, 17-hydroxyprogesterone, TFTs
- Progestogen challenge test
Why can pelvic ultrasound be useful for identifying causes of infertility?
useful in defining ovarian morphology, more reliable than pelvic examinatino in identifying potentially relevant pelvic pathology e.g. fibroids, ovarian cysts and endometrial polyps
Why might chlamydia serology be performed for female infertility?
screening test for tubal pathology - if positive antibody titre, more likely to have tubal pathology due to link with salpingitis
When is serum testosterone indicated for women with subfertility and what is it to exclude?
- If evidence of hirsutism
- To exclude sinister disorders such as androgen-secreting tumours of ovary or adrenal gland
What further blood test might you perform in women with elevated serum testosterone and why?
17-hydroxyprogesterone - to exclude late-onset congenital adrenal hyperplasia
Why might you perform thyroid function tests for female subfertility?
approx 7% women will have thyroid disorder, which may have impact on pregnancy if not appropriately treated
In which women with subfertility might you consider a progestogen challenge test?
history of amenorrhoea and normal levels of FSH and prolactin - to determine whether the woman is clinically oestrogenised