In Vitro Fertilization

Question 1

what is the definition of infertility?

Answer 1

inability to conceive within 12 months without contraception

Question 2

what is unexplained infertility? how is it treated?

Answer 2

evaluation fails to identify the problem

patients are treated for the most likely cause

Question 3

what are the common reasons for male infertility?

Answer 3

low sperm count, problems with quality of sperm, lack of sperm motility or genetic mutations

Question 4

what are the common causes of female infertility?

Answer 4

failure to ovulate, low supply of follicles, blocked fallopian tubes, endometriosis or uterine problems

Question 5

what are the three causes of problems with male fertility? overall what do they cause?

Answer 5

pathologies of reproductive system, environmental or lifestyle factors and systemic pathologies
cause oxidative stress to the sperm

Question 6

what does the ovarian reserve refer to? what causes its depletion?

Answer 6

the amount of viable follicles that a woman has. depleted mainly by follicular atresia and partially by ovulation

Question 7

when does fertility usually decline and at what point are spontaneous pregnancies rare? why does this occur?

Answer 7

declines at 35 and pregnancy is rare after 45

occurs because of a decreased number and quality of eggs

Question 8

what are the four treatments of infertility?

Answer 8

ovulation induction, reproductive tract surgery, intrauterine insemination and assisted reproduction

Question 9

what is intrauterine insemination? how are sperm chosen for this procedure?

Answer 9

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

Question 10

what types of problems are indicated for in vitro fertilization?

Answer 10

male fertility problem or tubal factors that would not allow normal fertilization to occur

Question 11

how is reproduction controlled by a physician in in vitro fertilization?

Answer 11

by downregulating the HPO axis to bypass it and control ovarian stimulation

Question 12

what is mullerian agenesis?

Answer 12

lack of mullerian structures with presence of ovaries (fallopian tubes and uterus)

Question 13

what types of molecules are used to downregulate the hypothalamic-pituitary-ovarian axis?

Answer 13

GnRH agonists (for the long protocol) and antagonists (for the short protocol)

Question 14

why do GnRH agonists down regulate LH and FSH secretion?

Answer 14

because receptors for GnRH are downregulated

Question 15

what is involved in controlled ovarian hyperstimulation?

Answer 15

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

Question 16

how are oocytes retrieved from follicles?

Answer 16

with ultrasound guidance

Question 17

what fertilization techniques are employed with in vitro fertilization?

Answer 17

standard oocyte insemination- put egg with many sperm

ISCI- intracytoplasmic sperm injection

Question 18

how does a doctor decide when to implant an embryo?

Answer 18

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

Question 19

what nuclear feature should be checked after fertilization and before implantation? when is this a concern?

Answer 19

should make sure that there are only two pronuclei after fertilization
this is a concern with dispermy that could occur in standard oocyte insemination

Question 20

what feature of the zona pellucida can inhibit embryo implantation?

Answer 20

the embryo may have a difficult time hatching from the zona pellucida (must happen before implantation)

Question 21

where should an embryo be placed to implant?

Answer 21

should be deposited 1 cm from the fundus

do not put it too close to the fallopian tubes for risk of ectopic pregnancy

Question 22

what determines the number of embryos transferred in IVF?

Answer 22

age of the mother and embryo quality. Also altered if the patient has had previous failed IVF cycles

Question 23

what are the four options for excess embryos?

Answer 23

freeae them, donate them for research, adopt them or discard them

Question 24

what age is the limiting factor of success for IVF?

Answer 24

age of the eggs (not age of the uterus)

Question 25

what danger comes with donating oocytes?

Answer 25

hyperstimulation- pelvic edema from overproduction of follicles leading to hemoconcentration and high hematocrit. Can cause many problems

Question 26

what are the indications for gestational surrogacy?

Answer 26

absent or anatomically abnormal uterus, medical contraindication, recurrent pregnancy loss and repeated IVF failures with good embryos

Question 27

what are the indications for preimplantation genetic diagnostics?

Answer 27

single gene defects, balanced translocation, advanced maternal age, repetitive IVF failure, recurrent pregnancy loss or embryo selection

Question 28

what are three parent embryos?

Answer 28

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

Question 29

what is human cloning?

Answer 29

taking a differentiated adult cell and implanting it into an egg and stimulating it to divide to make an entirely new individual