Embryology 4

Question 1

Biochemical Pregnancy

Answer 1

defined as an elevation in βhCG. Approximately 60% of all (+) hCG
never develop to live birth.

Question 2

“Clinical Pregnancy”

Answer 2

is defined as the first presence of a heartbeat.

Question 3

• Pre-Implantation Genetic Testing (PGT)

Answer 3

Removal of cells as early as the blastomeres of the ICM.

Question 4

Pre-Implantation Genetic Diagnosis (PGD)

Answer 4

Looking for a specific disease.

Question 5

Pre-Implantation Genetic Screening (PGS)

Answer 5

Looking for chromosomal normalcy and not a specific disease.

Question 6

• Congenital Malformations

Answer 6

Anomalies and disruptions to normal development which occur in utero or prior to birth. Often a result of “genetic abnormalities” particularly mutations
of genes for transcription factors, transduction factors and inducing factors.

Question 7

Trisomy 21 or “Down’s Syndrome”

Answer 7

results from an extra chromosomal segment at
position 21. The incidence of Down’s Syndrome increases significantly at the maternal age
of 35+ years.

Question 8

• Pleiotropy

Answer 8

Phenotypic effects produced by one gene expression.

Question 9

Mosaic Pleiotropy

Answer 9

an abnormal gene “independently” affects different organs/systems.

Question 10

Relational Pleiotropy

Answer 10

abnormal gene only affects a single organ development but then other organs are affected by that organs “normal/abnormal” development.

Question 11

• Infertility

Answer 11

Inability to conceive after one full year of attempts

Question 12

Assisted Reproductive Technologies (ART)

Answer 12

lab techniques used to assist in fertilization such as
drug therapy and in-vitro fertilization.

Question 13

• In-Vitro Fertilization (IVF)

Answer 13

Louise Brown” (1978), The worlds first “Test Tube Baby”

Question 14

• Gamete Intrafallopian Transfer (GIFT) & Zygote Intrafallopian Transfer (ZIFT)

Answer 14

Modified versions of IVF involving retrieval of eggs. Considered faster processes because of the timing of the transfer (implantation). GIFT & ZIFT require a surgical procedure to access the fallopian tube(s) that IVF does not.

Question 15

• GIFT

Answer 15

Sperm and the eggs are mixed together in-vitro then re-implanted into the fallopian tube with the hope that fertilization will then occur.

Question 16

• ZIFT

Answer 16

Fertilization occurs in-vitro then the zygote (fertilized egg) is placed into the fallopian tube.

Question 17

• Intracytoplasmic Sperm Injection (ICSI)

Answer 17

Injecting sperm cells into the eggs in-vitro to create a fertilized egg. Generally used in cases of male factor infertility such as “Kartagener’s Syndrome” where there is a decreased or absence of sperm motility.

Question 18

Gonal F® & Follistim®

Answer 18

Drugs which hyperstimulate the ovaries to increase the quality (and quantity) of egg productio

Question 19

Gonal F®

Answer 19

Generally least expensive of the two drugs and will typically produce more eggs.
Studies have found that in some cases, the drug may make the uterus less receptive to
the implantation of the embryo.

Question 20

Follistim®

Answer 20

Will generally produce better “quality” eggs than does Gonal F®.

Question 21

Better media

Answer 21

has been developed that will mimic the Ampulla region during the in-vitro period of fertilization. This allows for the embryo to be kept in the dish for an extended period of time (2-3 days) or until the Blastocyst stage. Can provide for a selection of the “better” embryos which will be more likely to implant and survive.

Question 22

Uterus Transplants

Answer 22

In cases of uterine cancer or where the uterus has been removed and in situations of excessive fibroid tissue

Question 23

Microscopic Testicular Sperm Extraction (micro-TESE)

Answer 23

Identifying areas of the testicle that has the best sperm (number & quality) production. Sperm are removed for use in various ART.

Question 24

Diets, Exercise, Sleep, & Lifestyle

Answer 24

An improvement in all categories may improve the gamete production and fertility in both women & men

Question 25

Pre-Eclampsia

Answer 25

Typically presents with high blood pressure and the presence of high protein levels in the urine of pregnant women, indicative of kidney damage and other organ failures or damage.
However, some women may present with only organ damage and not the classical signs of high blood pressure and protein in the urine, therefore the definition of pre-eclampsia was rewritten in 2014.
The causes of pre-eclampsia are not well understood however it is thought to be due in part to poor blood flow and improper functioning of the placenta in conjunction with a high fat diet and overall poor nutrition.
Research study (2017) found that the use of daily aspirin could reduce the chances of developing pre-eclampsia, however high doses of aspirin may also cause bleeding tendencies with a loss of pregnancy or congenital birth defects.

Question 26

Treatment for Cervical & Endometrial Cancer

Answer 26

Trachelectomy is a surgical removal of the uterine cervix. As the uterine body is preserved, this type of surgery is a fertility preserving surgical alternative to a radical hysterectomy and applicable in selected younger women with early cervical cancer.

Question 27

Cryopreservation of Tissues

Answer 27

Vitrification is sometimes referred to as “fast freezing.” In this process, water molecules are removed and replaced with a higher level of preserving solution before being placed in liquid nitrogen. Freezing occurs in milliseconds and can help prevent cell degradation during the thawing, fertilization, and transfer process.

Question 28

• Teratology

Answer 28

The study of birth defects

Question 29

• Teratogens

Answer 29

Exogenous agents responsible for genetic abnormalities. Maximum susceptibility
occurs during the 3rd – 8th week of embryonic development due to the massive amount of gene
segments that are being expressed for commitment of stem cells to specific cell types.

Question 30

• Teratogenic Agents

Answer 30

Primarily drugs and chemicals that the mother consumes such as alcohol,
and certain antibiotics. May also include viruses, radiation, hyperthermia, and metabolic
conditions occurring in mom.

Question 31

• Fetal Alcohol Syndrome (FAS)

Answer 31

Most commonly occurring teratogen affecting gestational
development. Results in induced apoptosis of the nervous system and underdeveloped brain tissue.

Question 32

• Developmental Cancer

Answer 32

Cells that are developing abnormally and are generally unresponsive
to their environment.

Question 33

• Teratocarcinomas

Answer 33

Malignant cells within the embryo that mimic or behave like the ICM and
therefore affect normal organ development.

Question 34

• Cancer Implications On Development;

Answer 34

1) Cancer cells may change the environment needed for normal development
2) Communication between cells is disrupted
3) Cadherin protein levels may be decreased (downregulated) affecting cell adhesion or binding affinity and allowing bad cells to drift away
4) Abnormal development may lead to abnormal “physiology”
5) Cancer may express the “anti-apoptosis” gene inhibiting normal turnover of cells

Question 35

• Benefits Gained From Study of Cancer

Answer 35

Among the benefits gained from the study of cancerous tumors is their absolute requirement for a
rich blood supply for oxygen and nutrients.

Question 36

Tumor Angiogenesis Factors (TAF

Answer 36

umor cells secrete a product similar to VEGF which
stimulates “angiogenesis”, or blood vessel formation into the tumor site.

• Blocking TAF and angiogenesis is one focus of oncology and the pharmaceutical industry to
  prevent tumor formation. The problem has always been how to avoid destruction of blood
  vessels supplying nearby healthy cells.
• The anatomy of capillaries associated with feeding the carcinoma positions are more permeable than “normal” capillaries of organs and tissue beds. This structural difference has provided an avenue for attacking the tumor sites with newer classes of “chemotherapeutic agents.”
• Multi-component anti-cancer drugs are designed to bypass the vascular supply of healthy tissue surrounding the tumor. Once reaching the tumor site the “outer coat”of the drug blocks the action of TAF destroying blood supply, only within the tumor, while the inner core of the drug exerts cytotoxic action to kill the tumor cells. “Nexavar”© , chemotherapeutic drug designed for renal & liver carcinomas is an example of this type of drug delivery system.

Question 37

• Gene Therapy

Answer 37

The ability to manipulate gene segments during the gestational period.
Somatic Cell Gene Therapy – altering the gene product within the “body” cell DNA of the
host. This will affect only the individual receiving the therapy.

Question 38

Germline Gene Therapy

Answer 38

correcting faulty gene segments in the host as well as their offspring.
This type of therapy would conceivably block the transmission of genetically predisposed or
inherited diseases and disorders.

Question 39

Embryonic Stem Cells

Answer 39

Pluripotent (capable of generating primary germ layers). Derived
from the ICM of the Blastocyst.

Question 40

Adult Stem Cells

Answer 40

Multipotent (capable of generating certain cell types) in humans and so
far only found to be pluripotent in animal models.

Question 41

Umbilical Stem Cells

Answer 41

Cord blood holds pluripotent stem cells. Common practice these days
to freeze a sample of cord blood at the time of birth of the child for future use

Question 42

Maternal Stem Cells

Answer 42

Fetal stem cells are found within the maternal blood circulation.