History of IVF

Question 1

Who is Dr. Berry Bavister?

Answer 1

1. Professor at U. New Orleans & EVMS
2. Expertise in mammal physiology and biochemistry (gametes, fertilization, preimplantation embryogenesis)
3. Research interests = sperm capacitation & mechanism for oocyte maturation
4. Wrote “Early History of IVF, Reproduction” in 2002.

Question 2

When was IVF first conceived in a mammal, by whom, and in which species?

Answer 2

1. 1959
2. M.C. Chang
3. Rabbit

Question 3

What is a strict definition of fertilization, and when does it start and finish?

Answer 3

Fusion of male and female gametes to form a zygote? If this is the correct definition then it starts perhaps after the sperm reaches the oocyte and ends after the two pronuclei become one. CHECK THIS DEFINITION before exam?

Question 4

Was GIFT performed first in human patients or in animals? What does GIFT stand for?

Answer 4

1. In rabbits (1934) but on accident; they thought they succeeded at IVF
2. GIFT = gamete intra-fallopian transfer

Question 5

Was human IVF based on earlier success in monkeys?

Answer 5

No, au contraire monkey IVF milestones came more slowly than human IVF. Human IVF was preceded by successes in mice, rats, hamsters, rabbits, and other little furries instead.

Question 6

In the 1960’s was sperm capacitation thought to be a barrier to IVF?

Answer 6

Yes, and Robert Edwards believed that his IVF attempts in 1964-65 failed because the sperm was not capacitated.

Question 7

Is capacitation required for fertilization in all mammals? And in non-mammals also?

Answer 7

So far, all mammals tested have needed capacitation for fertilization to occur. As for non-mammals it depends on whether or not they reproduce via external fertilization or internal fertilization. The sea urchin, for example, does not need capacitation (check on this to make sure?) because sperm needs to immediately fertilize the eggs on contact.

Question 8

Where does capacitation occur in the body?

Answer 8

Capacitation occurs in the female reproductive tract (uterus and oviducts) after progesterone stimulations begin to trigger events in some sperm that help prepare them for fertilization.

Question 9

Is there a trade off between sperm capacitation and longevity?

Answer 9

Not sure if I understand this question but some studies indicated a shorter sperm lifespan that comes with premature capacitation and so it’s logical that this is true. A sperm has no use after capacitation and the acrosome reaction is completed and so the length of time it takes for it to reach this point really does affect its lifespan.

Question 10

Is capacitation time species-specific?

Answer 10

Yes; mice capacitation occurs very quickly and human capacitation can take hours or even days.

Question 11

Is sperm capacitation required for hyperactivity?

Answer 11

Kind of–it’s an issue of semantics and arbitrary categorization, really. Hyperactivity does occur during the beginning stages of capacitation but there can be sperm with poor motility that are capacitated and used in ICSI, so it’s possible technically to bypass the physical signs of hyperactivity while still maturing enough for fertilization to occur.

Question 12

Does capacitation involve a morphological change?

Answer 12

Yes and no; the hyper activation stage does not but if the acrosome reaction is to be considered the terminal phase of capacitation then the morphological change would be the exocytosis of the acrosomal content and the loss of the sperm acrosome above the equatorial line. (check this info before test)

Question 13

What is the relationship between capacitation and the acrosome reaction?

Answer 13

Different publishers seem to disagree on the actual relationship because some (2002) suggest that the acrosome reaction is an independent event occurring post capacitation, but most textbooks today refer to the acrosome reaction as the terminal phase of the sperm capacitation.