Embryology: Teratogens

Question 1

What is the 4 effects of teratogens

Answer 1

1. Fetal loss (miscarriage & spontaneous abortion)
2. Growth restriction
3. Birth defects
4. Impaired neurological function

Question 2

What is the definition of teratogens

Answer 2

Substances that cause production of physical defect in development fembryo

Question 3

What is dysmorphogen

Answer 3

Agent/factor cause structural abnormality

Question 4

What is 6 examples of teratogens

Answer 4

1. Drugs
2. Substance abuse
3. Radiation
4. Chemicals
5. Maternal illness
6. Infectious agents

Question 5

What is the 6 organs/organs systems affected

Answer 5

1. CNS (ectoderm)
2. Heart
3. Renal
4. Abdominal wall
5. GIT
6. Skeleton

Question 6

What is 3 examples of congenital deformaties

Answer 6

Dislocation of hip, clubfoot or facial anomalies

Question 7

What causes disruption

Answer 7

Arise from mechanical or physiological factors

Question 8

What is 5 examples of congenital disruption

Answer 8

Amniotic band syndrome, fetal vascular occlusion, placental emboli, localised/general hypoxia or vascular insults

Question 9

When is the most sensitive period of embryological development & why

Answer 9

Embryonic period week 3-8 when organs are forming

Question 10

When does the risk for gross structural defect decrease

Answer 10

Fetal period week 8

Question 11

What structural defects can still occur in fetal period

Answer 11

Organ systems

Question 12

In what period does the brain develop

Answer 12

Fetal period

Question 13

What 2 things does toxic exposure result in

Answer 13

Learning & intellectual disability

Question 14

What is thalidomide

Answer 14

Drugs used for anti-emetic & anxiolytic drugs

Question 15

What is the 2 effects of thalidomide

Answer 15

Limb deformities: amelia (absence) micromelia (short) & phocomelia (abnormal)
Anti-angiogenesis: affect blood vessel during limb development

Question 16

What is 5 examples of infectious agents affecting fetal development

Answer 16

Toxoplasmosis
Other like varicella & congenital syphillis
Rubella
Cytomegalovirus
Herpes simplex virus/HIV

Question 17

What is 3 examples of environmental chemical

Answer 17

Organic mercury from fish
Polychlorinated biphenyls from fish
Lead from pork

Question 18

What is Minamata disease & the cause

Answer 18

Neurological disease
Caused by severe mercury poisoning

Question 19

What is 6 signs & symptoms of Minamata disease

Answer 19

Ataxia, numbness in hands, feet, general muscle weakness, loss of peripheral vision & damage to hearing & speech.

Question 20

To what is insulin dependent maternal diabetes linked to

Answer 20

Multiple congenital abnormalities

Question 21

What is 3 examples of multiple congenital abnormalities caused by diabetes

Answer 21

1. Cardiac & skeletal malformation (appendicular & axial)
   2.CNS alteration (holoprosencephaly)
2. Caudal dysgenesis (agenesis of sacral vertebrae & hind limb hypoplasia)

Question 22

What is the cause of 25% polyhydramnios

Answer 22

Maternal diabetes

Question 23

What is 3 consequences of disturbed CHO metabolism

Answer 23

Increased risk of stillbirths
Neonatal deaths
Abnormal large infants (macrosomia)

Question 24

What is used to control maternal diabetes & why

Answer 24

Insulin
Reduce congenital malformation risk

Question 25

What is the teratogens in maternal diabetes

Answer 25

Changes in glucose levels not insulin

Question 26

Why is stable glucose levels essential during pregnancy

Answer 26

Required for neurulating/gastrulating embryo

Question 27

What is holoprosencephaly

Answer 27

Cephalic disorder which prosencephalon fails to develop into 2 hemispheres