Assisted reproductive technology Flashcards
What is infertility?
Failure to achieve clinical pregnancy after 12 months of regular unprotected sex.
What are the types of infertility?
- Primary infertility: Infertility with no previous pregnancies.
- Secondary infertility: Infertility with previous pregnancies (including abnormal pregnancies)
What is fecundability?
Probability of woman engaging in regular unprotected sex conceiving within a menstrual cycle.
What is fecundity?
Probability of conceiving and achieving live birth within a menstrual cycle.
What are the types of male infertility?
- Aspermia: No semen in ejaculate
- Azoospermia: No sperm in ejaculate (but seminal fluid present)
- Oligospermia: Low numbers of sperm in ejaculate
- Asthenospermia: Poor sperm mobility
- Teratospermia: Malformed sperm
- Necrozoospermia: Dead or immobile sperm in ejaculate
- Oligoasthenoteratospermia (OATS): Combination of sperm defects
What are the categories of causes of male infertility?
- Pre-testicular: When infertility is caused by inadequate nutritional/endocrine support to the testes resulting in production of poor quality sperm.
- Testicular: Dysfunction of testicular tissue leading to abnormal production of sperm, even in presence of adequate nutritional/endocrine support.
- Post-testicular: Dysfunction of the male genital ducts so that even when good quality semen is produced, it cannot be delivered to the female.
What are the treatments for male infertility?
- Pre-testicular: Hormonal treatments may be given (e.g. hormone replacement).
- Testicular:
- IVF
- Intracytoplasmic sperm injection (ICSI)
- Percutaneous epididymal sperm aspiration (PESA) - Post-testicular:
- Surgical correction of blockage
- Viagra (erectile dysfunction)
What is the sequence of events that occur during the and ART cycle?
- Pituitary down-regulation using continuous administration of GnRH agonist (causes desensitisation).
- Baseline assessment to confirm down-regulation.
- Ovarian stimulation with recombinant FSH.
- Monitoring of follicular development using ultrasound.
- hCG injection to trigger ovulation.
- Collection of oocytes using ultrasound-guided oocyte retrieval
- ART technique (IVF or ICSI)
- Embryo transfer
- Luteal support and providing endocrine support using progesterone injections
What are the sequence of events that take place for IVF?
- Processing of maternal sample and identification of oocytes collected by OCR.
- Oocytes are placed in cell culture.
- Paternal semen sample is processed.
- Sperm mixed with oocytes in culture for 24-48 hours.
- Fertilised oocytes are identified and left to divide under supervision until blastocyst stage reached.
- Embryo (or embryos, to maximise chance of implantation) is transferred to mother or surrogate mother.
What is zona drilling?
Artificial introduction of holes in zona pellucida of oocytes to aid low motility sperm access to oocyte
What is the sequence of events that take place during ICSI?
- Hyaluronidase added to oocyte to remove surrounding cumulus cells.
- Procedure can only be carried out when metaphase II is reached in the oocyte (when 1st polar body is extruded).
- A single sperm is injected into egg using micropipette.
What is the sequence of events that place during artificial insemination?
- The semen sample is processed so that only the most mobile sperm are selected.
- In the woman, ovulation can occur naturally, or can be stimulated using FSH and hCG.
- The sperm is inserted into the uterus via catheter.
What are the common side effects of ART procedures?
- Ovarian hyperstimulation syndrome (OHSS): Overstimuation of ovaries causes over secretions of oestrogen, progesterone and other hormones/cytokines. This causes number of problems including abdominal bleeding, oedema (leading to ascites, pleural effusion…), nausea, vomiting…
- Multiple pregnancies, if multiple embryos are transferred into mother.
- Negative response to ovarian stimulation drugs.
- Post-operative bleeding and infections.
- Negative psychological impacts of failed ART attempts.
