9. developmental pathologies

Question 1

what percentage of fertilised eggs result in healthy outcomes

Answer 1

~33%

Question 2

what percentage of fertilised eggs do not implant

Answer 2

~40%

Question 3

how many babies born in NZ are affected by birth defects

Answer 3

~2-3%

Question 4

most common birth defect in NZ

Answer 4

congenital heart defects

Question 5

cryptorchidism

Answer 5

undescended testes

Question 6

malformation

Answer 6

a structural defect of a part of or an entire organ or body region
- primary errors of morphogenesis
- intrinsically abnormal developmental process

Question 7

disruption

Answer 7

a defect in an organ or body part caused by process that interferes with an originally normal development
- extrinsic disturbance

Question 8

deformation

Answer 8

a structural abnormality caused by mechanical forces
- extrinsic disturbance

Question 9

dysplasia

Answer 9

an abnormality of a tissue caused by an abnormal intrinsic developmental process

Question 10

sequence

Answer 10

a cascade of anomalies triggered by one initiating aberration

Question 11

syndrome

Answer 11

a group of malformations of different structures
- due to a single primary cause acting through multiple developmental pathways

Question 12

aneuploidy

Answer 12

abnormal chromosome number

Question 13

polyploidy

Answer 13

higher multiple than 2x haploid number of chromosomes
- not viable

Question 14

triploidy

Answer 14

3x 23 chromosomes likely due to
- fertilisation by more than one sperm
- lack of seperation of oocyte polar body

Question 15

monosomy

Answer 15

lack of one member of a chromosome pair

Question 16

trisomy

Answer 16

a triplet instead of a pair of chromosomes

Question 17

cause of Cri du chat

Answer 17

short arm of chromosome 5 missing

Question 18

transcervical infections

Answer 18

around time of birth

Question 19

transplacental infections

Answer 19

most parasitic and viral infections can cross the placenta
- can occur at any point

Question 20

high androgens during pregnancy

Answer 20

• masculinisation of female offspring
• accelerated genital development in male offspring

Question 21

synthetic estrogen in pregnancy

Answer 21

• cervical and uterine abnormalities
• cryptochordism in males
• cancers
• third generation effects?

Question 22

what percentage of natural pregnancies result in twins

Answer 22

~3%

Question 23

preconception diagnosis

Answer 23

carrier screening

Question 24

pre implantation diagnosis

Answer 24

• genetic screening (PGS)
• genetic diagnosis (PGD)

Question 25

prenatal diagnosis

Answer 25

- amniocentesis or chorionic villus sampling - ultrasound - maternal blood test

Question 26

neonatal diagnosis

Answer 26

apgar test and guthrie test

Question 27

how does a fetus acquire a transcervical infection

Answer 27

- inhaling infected amniotic fluid - from infected birth canal during delivery

Question 28

common result of transcervical infections

Answer 28

preterm birth - damage and rupture of amniotic sac due to inflammation - infiltrating neutrophils releasing prostaglandins

Question 29

when are transcervical infections most commonly transmitted to the fetus

Answer 29

very late in pregnancy

Question 30

when do transplacental infections most commonly get transmitted to the fetus

Answer 30

at any time during gestation

Question 31

CRS risk over pregnancy

Answer 31

reduces over the course of

Question 32

maternal infection of rubella in first trimester

Answer 32

fetal infection rate is ~85%

Question 33

maternal infection of rubella after 16 weeks

Answer 33

fetal infection rate ~50%

Question 34

maternal rubella infection results

Answer 34

- abortion - stillbirth - fetal growth restriction - CRS

Question 35

CRS congenital malformations

Answer 35

defects in - ocular - auditory - CVS - CNS

Question 36

prevention of CRS

Answer 36

immunisation prior to pregnancy

Question 37

covid-19 risks in pregnancy

Answer 37

mostly to mother, not to the fetus

Question 38

when does the neural tube anterior pore close

Answer 38

day 25

Question 39

when does the neural tube posterior pore close

Answer 39

day 28

Question 40

how common is neural tube pore fusion failure

Answer 40

~1/1000 births

Question 41

what are some causes of NTD

Answer 41

- genetic mutations - maternal infections - irradiation - maternal diabetes - low folic acid

Question 42

anencephaly

Answer 42

underdeveloped brain and incomplete skull

Question 43

spina bifida

Answer 43

spinal cord fails to develop and close normally

Question 44

when are fetuses most susceptible to NTD

Answer 44

first month of gestation when neural tube is forming and closing

Question 45

types of spina bifida

Answer 45

- spina bifida occulta - meningocele - myelomeningocele

Question 46

folic acid

Answer 46

essential B vitamin - synthesis of nucleotides for DNA synthesis, repair and methylation

Question 47

how many GDM mothers develop type II diabetes

Answer 47

50%

Question 48

results of GDM

Answer 48

fetal macrosomia birthing complications

Question 49

FASD discriminating craniofacial anomalies

Answer 49

- microcephaly - short palpebral fissures - smooth philtrum - thin upper lip

Question 50

foetal alcohol spectrum disorder

Answer 50

an umbrella term for a range of disabilities that result from exposure to alcohol during pregnancy

Question 51

amniocentesis time frame

Answer 51

15 to 20 weeks

Question 52

chorionic villus sampling time frame

Answer 52

10 to 14 weeks

Question 53

class I and II CFTR variants

Answer 53

little to no CFTR proteins

Question 54

Class III CFTR variants

Answer 54

gating defects

Question 55

Class IV CFTR variants

Answer 55

conductance defect

Question 56

Class V and VI CFTR variants

Answer 56

reduced CFTR proteins