Reproductive Technology
Chapter 21
Assisted Reproduction
When a couple is sub-fertile or infertile they
may need Assisted Reproduction to
become pregnant:
• Replace source of gametes
– Sperm, oocyte or zygote donors
• Aid in the fertilization process
• Replace the uterus
– Surrogate mothers
• Treat cause of infertility
Infertility
• Clinically defined as inability to conceive
after more than one year of intercourse
without contraception
• World Health Organization
– Defines sub-fertility as diminished ability to
conceive
– Infertility as complete inability to ever
conceive
• Personally
– Means changing your entire life plan
Infertility Statistics
• Affects about 1 in 6 couples in USA
• Cause can be identified in about 85% of
cases
• Can be treated successfully in about 85 –
90 % of couples
• Problem in female – 50%
• Problem in male – 30%
• Problem in both partners – 20%
Male Infertility
Problems:
• Oligospermia – low sperm count
– Caused by: hormones, environment, physical
• Poor sperm quality
– Motility – sperm can’t swim
– Abnormality – sperm are abnormally shaped
• Antibodies against own sperm
– Autoimmune disorder
Genetics of Male Infertility
• Oligospermia – low sperm count
– Genes: hormones, Y chromosome
abnormalities, testicular/prostrate development
– Environment: drugs, toxins, heat (kills)
• Poor sperm quality
– Genes: hormones, enzymes to harness energy
– Environment: drugs, toxins, heat (mutates)
• Antibodies against own sperm
– Genes: Immune system malfunctioning
Treatment of Male Infertility
• Primary – change environment
– Avoid heat, drugs, toxins
– Timing intercourse
• Secondary – correct hormone levels,
surgery corrects physical problems,
immune suppressants
• Final – Assisted Reproduction
Technologies
Female Infertility
Problems:
• Irregular/malfunctioning ovulation
– Hormone imbalance, malfunctioning or absent
ovaries or tubes
• Physical blockage
– Fibroids or Endometriosis
– Blocked/abnormal Fallopian tubes
• Vaginal secretions
– Hormones or certain diseases
Female Infertility
Genetics of Female Infertility
• Irregular/malfunctioning ovulation
– Genes: Hormones, thyroid, pituitary problems
– Environment: Birth control, stress
• Physical blockage
– Genes: Cancer, developmental defect
– Environment: Cancer or infections
• Vaginal secretions
– Genes: Hormones, mucus disorders, immune
Treatment of Female Infertility
• Primary – change environment
– Timing intercourse - checking for ovulation
– Decrease stress, diet, exercise, etc
• Secondary – correct hormone levels,
surgery to correct physical problems
• Final – Assisted Reproduction
Technologies
– More often necessary for female infertility
Infertility Testing
• Couple seek testing after trying for more
than one year
• Tests:
– Semen Analysis (male)
– Hormone levels checked (female)
– Physical exams (both)
– Hysterosalpingogram (HSG; female)
– Endometrial Biopsy (female)
– Post coital exam (done on female)
Assisted Reproductive
Technologies (ART)
• Donating gametes
• Surrogate mothers
• Helping bring gametes together
(fertilization)
• Putting zygote in correct place
• Preimplantation screening
Donating gametes
• Sperm donation:
– For Lesbian couple or male infertility
– Sperm can be inseminated into uterus or
cervix (artificial insemination)
– Or sperm can be mixed with oocyte and
zygote implanted
• Oocyte donation:
– Mixed with sperm and implanted as zygote
– More costly and harder to come by than
semen
Surrogate Mothers
• Book defines as “donating uterus”
– What else?
– Also time, energy, effort, hormones, blood,
diet, health care
• Surrogate mothers:
– Inseminated with father’s semen, using her
own oocytes
– Or may be implanted with a zygote from
couple’s gametes
• Legal rights of surrogate mothers vary by
state and country
Helping Fertilization
• IVF – in vitro fertilization
– Sperm and oocyte are mixed in Petri dish
– Embryo at 8 or 16 cell stage implanted into
uterus
• ICSI – intracytoplasmic sperm injection
– Sperm actually microinjected into oocyte
– Then embryo implanted into uterus
– Important when father has low sperm count or
large number of abnormal sperm
in vitro Fertilization (IVF)
• Problem is that egg and sperm can’t meet:
– Blocked tubes or abnormal structures
– Not enough healthy sperm
• Put sperm and egg together in dish and
then implant early embryo into uterus
• Costs $5,000 to 15,000 each try
• Success rate ~ 30%
• Children have ~ twice rate of birth defects
ICSI
• IVF where sperm is injected into oocyte
Improving IVF’s chances:
• Use ICSI
• Implanting more than one embryo
– What is the problem there?
• Implant embryos at later stage in
development (blastocysts)
• Culturing zygote with “helper” cells that
normally surround embryo
• Screening embryos for chromosomal
abnormalities
Helping Fertilization
• ZIFT – zygote intrafallopian transfer
– Same as IVF only implanted into fallopian
tube rather than uterus
– Less successful than IVF (~23%)
• GIFT – gamete intrafallopian transfer
– Deposit the sperm directly into fallopian tubes
– Or deposit sperm and oocytes (mother’s or
donor’s) into fallopian tubes
– Like IVF that happens internally (~26%)
Preimplantation Screening
Screening for genetic disorders BEFORE
pregnancy begins:
• One cell of 8 cell embryo is removed
• Single cell is karyotyped and probed with
FISH for specific genetic disorders
• Preimplantation Genetic Diagnosis (PGD)
• Only genetically “healthy” embryo is
implanted (IVF)
• ~ 29% success rate
PGD
• Screen for:
– Large chromosomal abnormalities
– Rare Mendelian Disorders
– Boys with X-linked disorders
• PGD often done on IVF embryos to screen
for chromosomal abnormalities commonly
associated with IVF procedure
• Weigh risk of disease vs. IVF not working
– Who could help make this decision?
“Spares”
• Every time IVF is done more embryos are
made than are used
• ~ 500,000 embryos are currently in deep
freeze in USA today from IVF
• Choices:
– Research – example: stem cells
– Donation to infertile couple
– Discard them
• Who should make this choice?
Adoption
• Domestic Adoptions:
– $5,000 to $40,000
– Must pass stringent screening process:
Salary, housing, marital situation, criminal
records
• International Adoptions:
– $7,000 to $30,000
– Different screening processes
• Foster Care Adoptions:
– Free or subsidized – older and abused children
Lets Talk about Ethics…
• Get into groups of four
Discuss what you think of each of these ART
situations as if you were:
1. One member of couple in question
2. Politician (pro life and pro ART)
3. Insurance company representative
4. Genetic counselor
Ethics of ART
1. A young, married couple is infertile. They
have basically no insurance because he
works as a free lance consultant and she
works two part time jobs. Although they
own a home and can afford to raise a child
they can not afford to undergo the testing
or treatments for their infertility. Neither
can they afford adoption.
Ethics of ART
2. A lesbian couple has one child. The
mother was inseminated from a sperm
donor and carried the baby produced from
her own oocyte. They happily raise the
child together for 6 years, until the mother
suddenly finds religion and decides that
homosexuality is wrong. When they break
up the mother wants the child but so does
her ex.
Ethics of ART
3. An infertile couple has insurance that
covers IVF but they don’t believe in using
ART because of their religion. They would
rather adopt, but their insurance doesn’t
cover adoption (most don’t) and they can’t
afford it.
Ethics of ART
4. An infertile couple uses Clomid (a drug
that stimulates ovulation) to become
pregnant. Suddenly they find themselves
pregnant with 6 embryos. They don’t
believe in selective reduction so they are
going to try to carry all 6 babies to term.
Their doctor knows that the babies won’t
be healthy. The father concurrently loses
his job, so now they have no insurance.
Ethics of ART
5. A couple wants to use PGD to make sure
they have a girl.
What would you think if:
a) They have 5 boys and want a girl
b) They live in China and can only have one
child
c) They know the mother carries an X
linked disease
Next Class:
• Read Chapter 22
• Homework – Chapter 21 Problems;
– Review: 1, 2, 9
– Applied: 1, 4, 5, 6, 10, 11