8.1: Reproductive system (embryology) 3

Question 1

why can things go wrong in transport of substances from mother to foetus?

Answer 1

1. placenta is NOT a true ‘barrier’
2. teratogens access the foetus via placenta
3. unintentional outcomes from physiological process (normal)

Question 2

what are teratogens?

Answer 2

agents causing malformation of embryo

Question 3

what are examples of teratogens that can access the foetus via placenta?

Answer 3

DRUGS:
thalidomide
alcohol
therapeutic drugs

Question 4

what are drugs that access the foetus via placenta? (non-teratogenic)

Answer 4

drugs of abuse

maternal smoking

Question 5

why can alcohol access the foetus via placenta and how does it cause damage?

Answer 5

small molecule

can damage CNS - lead to developmental defects e.g. slow reflexes, mental retardation, stunt skeletal growth

Question 6

how does tobacco affect foetus?

Answer 6

detrimental to foetal growth and development

Question 7

why is the foetus’ CNS vulnerable to damage during gestation?

Answer 7

takes a very long time to develop - large window for drug interference

Question 8

what does dysfunction in antibody transport of the foetus lead to?

Answer 8

haemolytic disease of the newborn

Question 9

what is haemolytic disease of the newborn?

Answer 9

rhesus blood group incompatibility of mother and foetus e.g. mother rhesus negative, foetus rhesus positive

Question 10

why is haemolytic disease of the newborn uncommon now-a-days?

Answer 10

because of prophylactic treatment given to the mother

Question 11

what are infectious agents which can cross the placenta and affect the foetus?

Answer 11

varicella zoster
cytomegalovirus (causes common flu in adults)
Treponema pallidum
Toxoplasma gondii
RUBELLA (but fine now due to mass immunisation)