[17] Causes of Infertility Flashcards
What is infertility?
The inability to become pregnant after one year of intercourse without contraception involving a male and female partner
80% of couples will conceive in year if what criteria are met?
- woman is under 40
- Don’t use contraception
- Have regular intercourse (every 2-3 days)
What is the cumulative pregnancy rate over 2 years with the same criteria?
90%
What happens with natural female fertility over time?
Declines with age
What are the 2 types of infertility?
- Primary
- Secondary
What is primary infertility?
When someone who has never had a child has difficulty conceiving
What is secondary infertility?
When someone who has had 1 or more pregnancies has difficulty conceiving
What are the broad causes of infertility?
- Ovulation disorders
- Tubal disease
- Uterine or cervical causes
- Coital dysfunction
- Male factor
- Unexplained infertility
What % of infertility cases are due to ovarian disorders?
25%
How many groups of ovulation disorders are there?
4
What are the 4 groups of ovulation disorders?
- Type I
- Type II
- Type III
- Type IV
What are Type I ovulation disorders also known as?
Hypothalamic-pituitary failure
Where are LH and FSH produced?
Anterior pituitary gland
What are FSH and LH responsible for?
Stimulating ovulation each month
What happens to LH, FSH and oestradiol in type I ovulation disorders?
Lowered
What can cause type I ovulation disorders
- Excess weight gain
- Very high or very low body weight
- Recent substantial weight gain
What can happen to menses as a result of type I ovulation disorders?
Absent or very infrequent
What is type II ovulation disorder also known as?
Hypothalamic-pituitary-ovarian dysfunction
What is the most common cause of type II ovulation disorders (and the majority of ovulation disorders)?
PCOS
What happens to levels of FSH in Type II ovulation disorders?
Normal
What happens to levels of LH in Type II ovulation disorders?
Normal or raised
What other hormones can be raised in Type II ovulation disorders?
- Serum anti-mullerian hormone
- Serum tesosterone
- Free androgen index
What are Type III ovulation disorders also known as?
Premature ovarian failure
What is premature ovarian failure?
Cessation of ovulation due to depletion of the ovarian follicle pool before 40
What happens to serum gonadotrophin levels in premature ovarian failure?
Greatly raised
What happens to levels of AMH in premature ovarian failure?
Low/undetectable
What happens to levels of Oestradiol in premature ovarian failure?
Low
What can cause premature ovarian failure?
- Autoimmune conditions
- Genetics
- Chemotherapy
What are Type IV ovarian disorders also known as?
Hyperprolactinaemia
What happens in Type IV ovarian disorders?
Pituitary gland produces too much prolactin leading to low oestrogen and may cause infertility
What is often the cause of hyperprolactinaemia?
Pituitary micoradenoma
What is an important cause of hyperprolactinaemia to rule out?
Space occupying macroadenoma
What is an iatrogenic cause of hyperprolactinaemia?
Medications e.g. antipsychotic drugs
What happens to prolactin levels in hyperprolactinaemia?
They go up obviously
What happens to levels of LH and FSH in hyperprolactinaemia?
Low/normal
What % of infertility cases are due to tubal disease?
20%
How do tubal disorders lead to infertility?
Damage or blocked tubes can keep the sperm from getting to the egg or block passage of the fertilised egg into the uterus
What are the potential causes of tubal disease?
- PID
- Previous surgery in abdomen or pelvis
- Pelvic tuberculosis
Give an example of previous pelvic or abdominal surgery that can cause infertility?
Surgery for ectopic pregnancy
What % of cases of infertility are caused by uterine or cervical causes?
10%
How can uterine and cervical disorders lead to infertility?
- Interfere with implantation
- Increase risk of miscarriage
What are some uterine disorders that can cause infertility?
- Benign polyps or tumours
- Endometriosis
- Uterine abnormalities present from birth
What congenital uterine abnormalities can cause infertility?
- Septum
- Bicornuate uterus
How do benign polyps or tumours of the uterus lead to infertility?
Can block fallopian tubes or interfere with implantation
What are some possible cervical causes of infertility?
- Cervical stenosis
- Sub-optimal mucus being produced
What can cause cervical stenosis?
- Inherited malformation
- Damage to the cervix
What sort of mucus is normally produced by endocervical cells at ovulation?
Clear, watery mucus with a high water content and specialised glycoprotein molecules
What does the mucus produced at ovulation normally facilitate?
Passage of sperm into the uterine cavity
What happens to the mucus after ovulation?
It becomes hostile to sperm under the influence of progesterone
What abnormalities of cervical mucus can lead to infertility?
- Cervical infection leading to altered mucus
- Antisperm antibodies in mucus
What problems with coitus can lead to infertility?
- Erectile dysfunction
- Premature ejaculation
- Painful intercourse
- Anatomical abnormalities e.g. hypospadias
- Psychological or relationship problems
What % of infertility cases are due to male factors?
30%
What are some male factors that can lead to infertility?
- Sperm/semen abnormalities
- Varicocele
- Infection
- Ejaculation issues
- Anti-sperm antibodies
- Tumours
- Chemo/radiotherapy
- Undescended testes
- Hormone imbalances
- Defects in tubules
- Genetic defects
- Coeliac disease
- Medications
- Previous surgery
- Environmental causes
- Health and lifestyle
What is a varicocele?
A swelling of the veins that drain the testicle
How do varicoceles cause infertility?
Unknown - possibly related to temperature regulation
What happens to sperm due to a varicocele?
Reduced quality
How common is varicocele as a cause of infertility?
Most common reversible cause of male infertility
What effects can infections have to lead to infertility?
- Interfere with sperm production
- Interfere with sperm health
- Block passage of sperm
What sorts of infections can lead to infertility?
- Epididymitis
- Orchitis
- Some STI’s including gonorrhoea and HIV
What ejaculation issues can lead to infertility?
- Retrograde ejaculation
- Inability to ejaculate
What is retrograde ejaculation?
When semen enters the bladder during orgasm instead of emerging through the penis
What conditions can cause retrograde ejaculation?
- Diabetes
- Spinal injuries
- Medications
- Surgery of bladder, prostate or urethra
What can cause inability to ejaculate?
- Spinal cord injuries
- Certain diseases
What genetic conditions can lead to male factor infertility?
- Klinefelter’s syndrome
- Cystic fibrosis
- Kallmann’s syndrome
- Kartagener’s syndrome
What is the genetic defect in Klinefelter’s syndrome?
Male born with XXY karyotype
What happens as a result of the XXY karyotype in Klinefelter’s?
Abnormal development of the male reproductive organs
What medications can lead to male factor infertility?
- Testosterone replacement
- Long-term anabolic steroid use
- Chemotherapy
- Certain anti-fungal medications
- Some ulcer drugs
What previous surgeries can lead to male factor infertility?
- Vasectomy
- Inguinal hernia repair
- Scrotal or testicular surgeries performed for testicular and rectal cancer
How can the environment lead to male factor infertility?
Exposure to certain elements can lead to reduced sperm production/function
What environmental factors can affect male fertility?
- Industrial chemicals
- Heavy metal exposure
- Radiation or x-rays
- Overheating the testicles
What lifestyle factors can affect fertility in men?
- Drug use
- Alcohol use
- Tobacco smoking
- Emotional stress/depression
- Obesity
What recreational drugs can lead to male infertility?
- Anabolic steroids
- Cocaine
- Marijuana
What effect do anabolic steroids have on male fertility?
Can cause testicular shrinkage and sperm production to decrease
How can cocaine or marijuana affect male fertility?
Temporarily reduce the number and quality of sperm
How can alcohol use lead to male infertility?
- Lower testosterone levels
- Can cause ED
- Decreased sperm production
- Can cause liver disease which can cause further fertility issues
What effect does tobacco smoking have on male fertility?
Lowers sperm count
What % of cases of infertility have no explanation?
25%
What is the likely reason for an unexplainable cause of infertility?
Combination of several minor factors in both partners
