Infertility Flashcards
What are the requirements for fertility?
- Production of normal sperm
- Production of normal eggs
- Sperm needs to traverse the female tract to reach the egg and fertilise it, which requires:
- Capacitation: gaining fertilisation competence
- Time constraints: needs to happen when the egg is in the fallopian tube.
- Sperm needs to penetrate the ZP and fertilise the oocyte
- Implantation of the embryo into the uterus
- A healthy normal pregnancy
What is fertility?
Fertility is a measure of the actual outcome of the reproductive process, i.e., the number of children born to an individual or couple.
What is fecundability?
Fecundability is the probability of conceiving each month, or the monthly chance of pregnancy, either for an individual or for a population.
What is fecundity?
Fecundity is a measure of the ability to conceive and produce a live birth.
What is infertility?
Infertility is the inability to conceive after a period of unprotected intercourse or the inability to carry a pregnancy to term.
The National Institute for Clinical Excellence (NICE) defines infertility as failing to get pregnant after two years of regular unprotected sex.
What is subfertility?
Subfertility is a state of reduced fertility, generally prompting people to seek medical advice after one year of trying to conceive.
What data supports the definition of subfertility?
Of 100 couples without a fertility issue trying to conceive naturally:
- 20 will conceive within one month
- 70 will conceive within six months
- 85 will conceive within a year
- 90 will conceive within 18 months
- 95 will conceive within two years
Is infertility a big problem?
Most couples are unaware of their fertility status until they wish to reproduce. It is estimated that one in six couples have difficulty conceiving.
What are the causes of infertility?
Around 35% of infertility has a male basis, 35% has a female basis, 15% has a basis in both partners, and 15% has no known cause.
What are self-inflicted factors that affect fertility?
Self-inflicted factors include:
1. Age
2. Smoking status
3. Obesity
4. Increasing prevalence of STIs such as chlamydia
What is the first step if a couple presents with perceived infertility?
Step 1: Take a history, including:
- How long have they been trying?
- Family history of infertility?
- Current sexual history?
- Past sexual history?
What are some female factors that could cause infertility?
Female factors include:
1. Ovulatory disorders
2. Tubal damage
3. Endometriosis
4. Uterine abnormalities
5. Problems with implantation, growth, and development
How can we diagnose the causes of infertility in women?
Diagnosis can involve blood analysis, surgery, and radiography, such as measuring FSH or progesterone levels, HSG, and laparoscopy.
What are some ovulation disorders that can cause fertility problems?
Ovulation disorders account for 40% of fertility problems and may include:
1. Absent cycles (Primary or Secondary amenorrhoea)
2. Irregular cycles (Oligomenorrhoea)
3. Anovulatory cycles
What can ovulation disorders be associated with?
Ovulation disorders can be associated with stress, obesity, strenuous exercise, anorexia nervosa, and drug use.
What are disorders of the female tract that can affect fertility?
Disorders include:
1. Tubal obstruction (often due to pelvic infection)
2. Endometriosis (ectopic endometrial tissue growth)
What are some maternal problems that can affect fertility?
Maternal problems account for 40-50% of fertility issues and can include:
1. Cervical incompetence
2. Implantation defects
3. Autoimmune effects
4. Immunological incompatibility
How is a biochemical pregnancy tested?
A biochemical pregnancy is tested by the presence of hCG in blood and urine 18-30 days after the initiation of the last period.
How is a clinical pregnancy detected?
A clinical pregnancy is detected on ultrasound, with a sac visible at 5 weeks and a fetal heart at 7 weeks.
What are reasons for spontaneous pregnancy loss?
4/5 cycles involving unprotected intercourse do not result in pregnancy. Up to 15-25% of clinical pregnancies fail, usually in the first trimester.
What percentage of pregnancy losses are due to abnormal conceptus?
50-60% of losses are due to genetic abnormalities in the conceptus.
What categories can chromosomal abnormalities be split into?
Chromosomal abnormalities can be categorized into:
1. Translocations
2. Errors of ploidy
3. Errors of chromosome number or ‘somy’
What is the effect of delayed reproduction on fertility?
Aneuploidy in oocytes becomes more common with increasing maternal age, leading to higher miscarriage rates and lower live birth rates.
What are emerging diagnostics for females in IVF?
Emerging diagnostics include tests for endometrial receptivity to determine the optimal time for embryo placement.
What can cause male infertility?
Male infertility can be caused by issues with:
1. Production of spermatozoa
2. Transport of spermatozoa
3. Transmission of spermatozoa to female
4. Sperm function in the female tract
5. Competency for fertilization
How can we evaluate an infertile male?
Evaluation aims to identify:
1. Correctable conditions
2. Irreversible conditions requiring assisted reproductive techniques
3. Life-threatening conditions
4. Genetic abnormalities affecting offspring health
What is the initial diagnostic approach for a male with fertility issues?
Initial steps include:
1. Taking a reproductive history
2. Conducting a semen analysis
3. Possibly performing additional blood analyses
What does examination of the male involve?
Examination includes:
1. General health assessment
2. Genital examination
3. Checking for signs of endocrine disease
4. Abdominal examination
When is an endocrine evaluation done for males?
An endocrine evaluation is done if sperm concentration is abnormally low, if there are reports of impaired sexual function, or if there are clinical findings suggestive of endocrinopathy.
What indicates a need for further evaluation in male fertility?
If man has abnormally low sperm concentration especially if < 5 million/ml, impaired sexual function, or other clinical findings suggestive of a specific endocrinopathy.
What are the WHO reference values for sperm analysis based on?
The reference values are set by the WHO manual and refer to the chance of what you’re seeing as being a normal result.
What is the significance of the WHO sperm analysis reference values?
Data comes from contraceptive trials and describes 95% of men that have a conception within 6 months of trying.
What does it mean if a man has a sperm analysis result worse than the WHO reference values?
It does not tell you a man can’t have his own genetic children; better to think about them as being atypical.
What are the categories of ejaculate grading?
Normozoospermic, Oligozoospermic, Asthenozoospermic, Teratozoospermic, and Azoospermic.
What defines a Normozoospermic ejaculate?
> 15 million spermatozoa/ml; >32% rapid forward progressive motility and >4% normal morphology.
What defines an Oligozoospermic ejaculate?
<15 million spermatozoa/ml.
What defines an Asthenozoospermic ejaculate?
<32% rapid and medium forward progressive motility.
What defines a Teratozoospermic ejaculate?
<4% spermatozoa with normal morphology.
What is Azoospermic?
No sperm present in the ejaculate.
What are some causes of failure in sperm production?
Congenital testicular deficiency, maldescended testes, acquired injury, and endocrine disorders.
What additional tests can be done on sperm besides basic analysis?
Leucocyte count, sperm viability tests, anti-sperm antibodies, and computer-aided sperm analysis.
What are non-standard tests for sperm function?
DNA damage tests, aneuploidy tests, oxidative stress tests, cervical mucus penetration tests, hemizona assay, acrosome reaction tests, and zona-free hamster egg sperm penetration tests.
What can cause failure in the transmission of sperm from penis to vagina?
Erectile dysfunction and ejaculatory dysfunction.
What is the process of normal ejaculation?
Contraction of musculature of prostate, seminal vesicles, and vas deferens propels seminal fluid and sperm down the urethra.
What is retrograde ejaculation?
Incompetence of internal urethral sphincter resulting in ejaculation into the bladder.
When is post-ejaculatory urine analysis done?
Indicated for low volume ejaculate or absent ejaculate.
What could cause a total failure in sperm transport?
Post infectious causes or congenital bilateral absence of vas deferens (CBAVD).
When is genetic testing done in male infertility?
In men with non-obstructive azoospermia or oligozoospermia.
What are some male chromosomal disorders linked to infertility?
Abnormal karyotypes, Y chromosome microdeletions, and conditions like Klinefelter’s syndrome.
What is Congenital Bilateral Absence of the Vas Deferens (CBAVD)?
Linked to CFTR gene mutation, causing improper development of vas deferens.
What is necessary for men with CBAVD seeking reproduction?
Sperm can be taken from testes or epididymis for assisted reproduction, and partner screening for CF mutation is necessary.
What are the post-fertilization processes of sperm?
Sperm delivers centriole to oocyte, chromatin decondensation, protamine exchange, pronuclear fusion, and activation of genes for placenta formation.
How can we define unexplained infertility?
Normal frequency of intercourse, no obstructions, normal sperm concentration, and no signs of inflammation.
What do assisted reproduction techniques aim to do?
Move or avoid different barriers that exist in natural conception.
