In Vitro Fertilization Flashcards
what is the definition of infertility?
inability to conceive within 12 months without contraception
what is unexplained infertility? how is it treated?
evaluation fails to identify the problem
patients are treated for the most likely cause
what are the common reasons for male infertility?
low sperm count, problems with quality of sperm, lack of sperm motility or genetic mutations
what are the common causes of female infertility?
failure to ovulate, low supply of follicles, blocked fallopian tubes, endometriosis or uterine problems
what are the three causes of problems with male fertility? overall what do they cause?
pathologies of reproductive system, environmental or lifestyle factors and systemic pathologies
cause oxidative stress to the sperm
what does the ovarian reserve refer to? what causes its depletion?
the amount of viable follicles that a woman has. depleted mainly by follicular atresia and partially by ovulation
when does fertility usually decline and at what point are spontaneous pregnancies rare? why does this occur?
declines at 35 and pregnancy is rare after 45
occurs because of a decreased number and quality of eggs
what are the four treatments of infertility?
ovulation induction, reproductive tract surgery, intrauterine insemination and assisted reproduction
what is intrauterine insemination? how are sperm chosen for this procedure?
refers to injecting sperm into the uterus of a woman. sperm are chosen by allowing a tube of them to settle. the ones that are at the bottom are most likely viable because they are the best swimmers
what types of problems are indicated for in vitro fertilization?
male fertility problem or tubal factors that would not allow normal fertilization to occur
how is reproduction controlled by a physician in in vitro fertilization?
by downregulating the HPO axis to bypass it and control ovarian stimulation
what is mullerian agenesis?
lack of mullerian structures with presence of ovaries (fallopian tubes and uterus)
what types of molecules are used to downregulate the hypothalamic-pituitary-ovarian axis?
GnRH agonists (for the long protocol) and antagonists (for the short protocol)
why do GnRH agonists down regulate LH and FSH secretion?
because receptors for GnRH are downregulated
what is involved in controlled ovarian hyperstimulation?
a superphysiologic amount of FSH is given to the patient to stimulate many dominant follicles. hCG is used to mimic the LH surge because it has a longer half life and then follicles are harvested
how are oocytes retrieved from follicles?
with ultrasound guidance
what fertilization techniques are employed with in vitro fertilization?
standard oocyte insemination- put egg with many sperm
ISCI- intracytoplasmic sperm injection
how does a doctor decide when to implant an embryo?
if there are many embryos, the doctor may wait until the blastocyst stage (day 5) because it is more likely to take
if there are only a few embryos, the doctor will implant at the 4-8 cell stage so they have a higher chance of survival
what nuclear feature should be checked after fertilization and before implantation? when is this a concern?
should make sure that there are only two pronuclei after fertilization
this is a concern with dispermy that could occur in standard oocyte insemination
what feature of the zona pellucida can inhibit embryo implantation?
the embryo may have a difficult time hatching from the zona pellucida (must happen before implantation)
where should an embryo be placed to implant?
should be deposited 1 cm from the fundus
do not put it too close to the fallopian tubes for risk of ectopic pregnancy
what determines the number of embryos transferred in IVF?
age of the mother and embryo quality. Also altered if the patient has had previous failed IVF cycles
what are the four options for excess embryos?
freeae them, donate them for research, adopt them or discard them
what age is the limiting factor of success for IVF?
age of the eggs (not age of the uterus)
what danger comes with donating oocytes?
hyperstimulation- pelvic edema from overproduction of follicles leading to hemoconcentration and high hematocrit. Can cause many problems
what are the indications for gestational surrogacy?
absent or anatomically abnormal uterus, medical contraindication, recurrent pregnancy loss and repeated IVF failures with good embryos
what are the indications for preimplantation genetic diagnostics?
single gene defects, balanced translocation, advanced maternal age, repetitive IVF failure, recurrent pregnancy loss or embryo selection
what are three parent embryos?
the nucleus from an egg with mitochondrial abnormalities is transplanted into another enucleated egg. this egg is then fertilized giving it DNA from three parents
what is human cloning?
taking a differentiated adult cell and implanting it into an egg and stimulating it to divide to make an entirely new individual
