Prenatal & Infertility Procedures

Can you think of some ways we can learn about a developing fetus before it is born?

What do you think can be discovered through these tests? Gene mutations Incorrect chromosome numbers (nondisjunction) Physical abnormalities Gender (male or female) Would you use a prenatal procedure? Why might such screening be considered unethical?

Ultrasound  sound waves to create a 3D image (sonogram)

Amniocentesis A syringe removes amniotic fluid containing fetal cells DNA used for a karyotype of the chromosomes high risk pregnancies

Chorionic Villus Sampling catheter inserted through vagina into uterus to sample villi of placenta more fetal cells, earlier in pregancy

Egg Collection Eggs removed to be tested before in vitro fertilization Whose genes are tested?

Which procedure would you choose? Any risks?

Would you want to know if you are carrying a mutated gene that will produce a disease? Ex. Huntington’s Disease – a mutated gene produces an abnormal protein needed for nerve cell functioning Nervous system deteriorates (loss of memory, involuntary jerky movements) but does not produce symptoms until 30 – 50 years of age No cure  death usually within years due to complications (ex. falling or choking) There is a test to determine the base sequence of the gene on chromosome 4 Would you get tested if your parents had Huntington’s disease?

What are some reasons why people cannot conceive (are infertile) Unhealthy sperm or eggs Low sperm or egg count Ovaries or testes not functioning to produce eggs or sperm Not enough hormones for egg production Uterus unable to carry a fetus to term Age

Can you think of some reproductive technologies to treat infertility?

Fertility Drugs Stimulates hormones so more eggs produced Increases chance of conception Would you risk the chance of multiple births?

Artificial or Intrauterine Insemination Sperm placed in vagina or uterus Ex. when low sperm count or from sperm bank

Gamete Intrafallopian Transfer Eggs removed from ovary, then reinserted into the oviduct with sperm (where fertilization normally occurs)

In Vitro Fertilization Eggs and sperm are fertilized in a petri dish Embryo is inserted in uterus of mother or surrogate mother

Intracytoplasmic Sperm Injection A single sperm is injected into an egg When sperm count very low or can’t swim properly

Surrogacy Would you use a surrogate mother if you or your partner could not carry the child? Who would you ask? Would you be a surrogate mother to fund your college tuition? Who gets to make the decisions when there are complications during pregnancy? Does surrogacy exploit the female body? Is surrogacy a selfish idea when there are many orphans to be adopted?

Ch. 4 Test on Tuesday (next class) Make sure your notes are complete Read the Chapter Summary on pages 140 – 141 Try Questions from the Review on pages 142 – 143