Infertility Flashcards
What is the definition of fertility?
The ability to conceive
What is the definition of fertility rate?
Number of births per female
What is the definition of fecundability?
The probability of conception in a month or in one menstrual cycle
What is the definition of fecundity?
The probability of a live birth from one menstrual cycle
What is the definition of infertility?
Failure to achieve pregnancy following 12 months or more of unprotected sex
What is the definition of subfertility?
Reduction in fertility
What is the definition of sterility?
Permanent loss of fertility
What is the global prevalence of infertility?
Approximately 1 in 6 people suffer from infertility at some point in their lives
What might be behind the decline in global fertility rate? (3)
- Increased access to education
- Lower child mortality
- Increased cost of raising children
Why did fertility rate decline so dramatically in South Korea?
Introduction of a one-child policy
What might be behind the slight upward trend in infertility prevalence between 1990-2017? (2)
- Increased reporting of clinical infertility due to improvements in assisted reproductive technologies
- Lessening taboo of infertility
What might be behind the data showing declining sperm counts? (2)
- Suggested factors include exposure to hormones and chemicals that interfere with spermatogenesis
- Some scientists argue that trend is due to changes in counting assays
How does fecundity change with age?
Declines with age
Where does infertility originate? (4)
- 30% male
- 30% female
- 20% combined
- 20% unexplained
What factors can be involved in male infertility? (3)
- Sperm production
- Sperm transport
- Sexual dysfunction
What is oligozoospermia? (3)
- Low sperm count
- 1 in 20 males
- Accounts for around 1/3 of couples with difficulty conceiving
What is asthenozoospermia? (2)
- Low sperm mobility
- Sperm movement is impeded meaning they can’t reach the egg
What is teratozoospermia? (2)
- Abnormal sperm
- May have an unusual shape making it harder to move and fertilise an egg
What is azoospermia? (2)
- No sperm
- 1 in 100 males
What issues with sperm production can cause male infertility? (5)
- Varicoceles (40% cases of male primary infertility)
- Undescended testes (1-9% full-term male infants)
- Chromosomal abnormalities e.g. Klinefelter’s (XXY)
- Hormonal problems e.g. hypogonadotrophic hypogonadism
- Lifestyle e.g. stress, diet, alcohol, drugs, heat
What issues with sperm transport can cause male infertility? (4)
- Infection e.g. chlamydia
- Tube blockages e.g. vasectomy
- Tumours
- Congenital absence of vas deferens e.g. in cystic fibrosis
What issues with sexual dysfunction can cause male infertility? (4)
- Retrograde ejaculation
- Spinal cord injury
- Prostate surgery
- Some medications
What is a varicocele? (3)
- Most common in the left testicle because blood flows backwards down the internal spermatic vein causing dilation of the veins in the left testicle
- This increases blood flow and therefore temperature and reactive oxygen species (ROS) (Agarwal et al., 2006) which interferes with normal spermatogenesis
- Varicocele repair surgery improves rates of pregnancy, live births and sperm retrieval (Birowo et al., 2020)
What factors can be involved in female infertility? (3)
- Oogenesis and ovulation
- Oocyte/zygote transport and implantation
- Issues with pregnancy
What issues with oogenesis and ovulation can cause female infertility? (5)
- Age due to decreased ovarian reserve and decline in egg quality
- Hormone imbalance e.g. PCOS
- Over or underactive thyroid
- Premature ovarian failure (menopause before 40)
- Genetic causes e.g. Turner syndrome (female born with 1 X chromosome)
What issues with oocyte/zygote transport and implantation can cause female infertility? (5)
- Tubal damage due to infection or previous ectopic pregnancy
- Endometriosis
- Fibroids
- Surgical damage during previous pregnancy
- Pelvis inflammatory disease
What issues with pregnancy can cause female infertility? (4)
- Chromosomal abnormalities
- Structural issues with the uterus
- Autoimmune conditions
- Lifestyle factors e.g. drugs, alcohol, high BMI
What is polycystic ovarian syndrome (PCOS)? (6)
- Most common endocrine disorder in females of reproductive age
- Associated with irregular or absent menstrual cycles
- Hormonal balance leads to over recruitment but underdevelopment of follicles so ovaries have lots of half-developed follicular cysts
- Pituitary produces lots of LH which causes thecal cell expansion and therefore high androgen (testosterone) production causing acne and hirsutism
- Also impacts insulin resistance and liver enzyme function resulting in weight gain
- Low FSH production by the pituitary causes early follicular arrest
How is infertility diagnosed? (5)
- Full patient history: lifestyle, STIs, length of time trying to conceive, previous oral contraceptive use (post-pill amenorrhoea), family history
- Physical examination: BMI, pelvic infection, tenderness, testicle structure
- Males: semen analysis initially then hormone analysis
- Females: blood hormone analysis
- Test for chlamydia
