Assisted reproduction: IVF and ICSI Flashcards
What is IVF
In vitro fertilization
Been successfully used since 1978
What are the main steps of IVF
stimulation
egg retrieval
insemination and fertilization
embryo transfer
What is involved in the stimulation step
Super ovulation
Ovaries stimulated by hormones like FSH and LH to produce eggs
During this time, the woman will have transvaginal ultrasounds to examine ovaries
What is involved in egg retrieval
Invasive surgery-follicular aspiration (suck liquid and follicle with oocyte)
Needle inserted into mature follicles- connected to suction device
What is involved in insemination and fertilization
Sperm placed with eggs and put in incubator
The mixing of sperm and egg is called insemination
What is involved in embryo transfer
After several days , embryos ready to be transferred into uterus by flexible cannula
In most cases, 4-10 cell stage embryos are transferred. In some special cases,
the incubation in vitro is longer, and blastocysts are transferred.
What can be done if fertilization is so low even IVF will not work
eg sperm cant penetrate egg due to defect
Intracytoplasmic sperm injection
ICSI- directly inject sperm into egg
In what cases is ICSI recommended
- Male very low sperm count
- poor morphology/motility of sperm
- several unsuccessful in vitro attempts
- the male partner has had a vasectomy and sperm must be collected from the testicles or epididymis
- the male partner has had problems obtaining an erection and ejaculating. This includes men with spinal cord
injuries, diabetes and other disorders.
How are the oocytes cultivated
- Petri dishes 37’C (mimick body temp)
- liquid parafin prevents evaporation of the drop
- pH indicator shows change in colour, when it turns red put straight into incubator (they have to be manipulated fast)
Why do you need to know the position of the polar body when doing ICSI
When we inject sperm, you CANNOT destroy spindle so you have to inject away from the polar body
What type of nuclei does zygote have
HAPLOID (24 hrs after mixing of gametes)
Zygote is never diplod as the 2 pronuclei never fuse
Where does sperm capacitation occur
In vagina of female
Breaks down cholesterol layer of sperm head
ATP generating system starts working so sperm becomes hyperactive- flagellum starts to move
sperm become functionally mature in women