5 - foetal growth

Question 1

define foetal growth and how its assessed

Answer 1

the increase in mass between the end of the embryonic period and birth

symphysis fundal height (SPH) and US scans

Question 2

what type of cell growth occurs in which weeks

Answer 2

4-20 weeks = cellular hyperplasia
20-28 weeks = hyperplasia and hypertrophy
28-40 weeks = hypertrophy

Question 3

factors that could cause a lower or a higher than expected symphysis fundal height

further consideration of using SPH

Answer 3

lower

• wrong last menstrual period date
• transverse baby position
• complications e.g. SGA or oligohydramnios

higher

• wrong last menstrual period date
• multiple pregnancy
• maternal obesity
• complications: LGA, polyhydramnios, fibroids, molar pregnancy

inter-examiner variability
data base of ‘normal’ size historically based on miscarriages or premature births –> these may be inaccurate of a ‘normal’ size

Question 4

why ultrasound is used/ what is it used for

Answer 4

assess foetal size and progressive growth
sequential measurements important

to identify normal intrauterine growth
detect risk of complications
dating of pregnancy

Question 5

Biometrical parameters to assess baby’s …..

Answer 5

assess estimated foetal weight

biparietal diameter (BPD)
head circumference (HC)
abdominal circumference (AC)
femur length (FL)
crown rump length

Question 6

factors that influence growth

Answer 6

genetic - height and weight of parents and siblings

environmental - placental health (uterine and placental vascularity - hormonal control and substrate exchange)

• maternal nutrition
• maternal age
• m smoking
• m drug use
• m disease - mental and physical

Question 7

small for gestational age is defined as

Answer 7

birthweight below the 10th centile

Question 8

intra-uterine growth restriction definition

Answer 8

failure of infant to achieve its predetermined genetic potential

Question 9

LBW, VLBW and ELBW grams at delivery

Answer 9

LBW <2500g
VLBW <1500g
ELBW <1000g

Question 10

why is it important to distinguish between LBW and IUGR

Answer 10

IUGR babies have greater morbidity and mortality rate

Question 11

IUGR - evidence that…, major cause of, can cause what risks to the mother, when does it normally occur,

screening and diagnosis

management

Answer 11

evidence growth has altered (change in growth trajectory on centile chart)
major cause of foetal death and complications
can cause pre-eclampsia
occurs usually during the 2nd and 3rd trimesters

doppler, US, maternal BP, cardiotocography

manage by balancing growth restriction vs. prematurity
deliver too late and growth restriction continues — foetal demise
deliver too early — prematurity