Large/Small for Gestational Age

Question 1

define large for gestational age

Answer 1

> 90th percentile of estimated foetal weight

Question 2

LGA also known as

Answer 2

macrosomia

Question 3

birth weight of a baby considered large for gestational age

Answer 3

> 4.5kg at birth

Question 4

other than constitutional, give some reasons that a foetus may be large for gestational age

Answer 4

maternal diabetes

maternal obesity

maternal rapid weight gain

previous macrosomal baby

overdue

Question 5

6 risks to the mother as a result of macrosomia

Answer 5

shoulder dystosia

failure to progress

perineal tears

uterine rupture (rare)

necessity of instrumental delivery

PPH

Question 6

4 complications to the child as a result of macrosomia (2 immediate and 2 long term)

Answer 6

increased risk of birth complication e.g. Erb’s palsy

neonatal hypoglycaemia (due to raised insulin?)

obesity

T2DM

Question 7

other than macrosomia, what else will cause a larger than normal uterus?

Answer 7

polyhydramnios

multiple pregnancy

Question 8

mothers with macrosomal babies should be investigated for

Answer 8

polyhydramnios

multiple pregnancy

Question 9

true or false: the vast majority of LGA babies will have complicated births

what is the implication of this?

Answer 9

false; most LGA babies will have a normal vaginal delivery

NICE does not recommend induction of labour on the grounds of macrosomia alone

Question 10

main risk of vaginal delivery with a LGA baby

Answer 10

shoulder dystocia

Question 11

define SGA

Answer 11

below the 10th centile for their gestational age

Question 12

how is foetal size estimated? (2)

Answer 12

USS can be used to determine:

estimated foetal weight

abdominal circumference

Question 13

suggest 4 factors which need to be taken into account when considering if a foetus is SGA (4 maternal factors)

Answer 13

ethnicity

weight

height

parity

Question 14

define severe SGA

Answer 14

below the third centile

Question 15

define low birth weight

Answer 15

<2500 g

Question 16

2 broad causes of SGA

Answer 16

constitutionally small (matching the mother/the family; normal growth velocity)

IUGR

Question 17

2 broad causes of IUGR

Answer 17

placental problems e.g. pre-eclampsia, maternal anaemia

foetal problems e.g. chromosomal abnormalities, foetal infections

Question 18

4 indications of IUGR as opposed to constitutionally small

Answer 18

reduced foetal movements

abnormal CTGs

reduced amniotic fluid volume (basically means oliguria)

abnormal doppler studies

Question 19

4 short term complications of SGA

Answer 19

foetal death

birth asphyxia

neonatal hypothermia

neonatal hypoglycaemia

Question 20

4 long term complications of SGA

Answer 20

cardiovascular disease

mood disorders

T2DM

obesity

Question 21

which serum marker can indicate that a foetus is SGA?

Answer 21

PAPPA (low PAPPA = small foetus)

Question 22

which extreme of age is more likely to have a SGA foetus?

Answer 22

older mothers

Question 23

which extreme of age is more likely to have a SGA foetus?

Answer 23

older mothers

Question 24

when are pregnant patients assessed for their risk of having a SGA baby?

Answer 24

at the booking clinic

Question 25

how are patients who are considered low risk of having a SGA foetus monitored for IUGR?

Answer 25

with serial symphysis fundal height measurements | if these are abnormal then proceed to serial growth scans

Question 26

how are patients who are considered high risk of having a SGA foetus monitored for IUGR?

Answer 26

serial growth scans

Question 27

in addition to foetal weight and abdominal circumference, what else is taken at the time of a serial growth scan? (2)

Answer 27

umbilical artery doppler amniotic fluid volume

Question 28

3 reasons to use serial growth scans over symphysis/fundal height

Answer 28

1 major risk factor 3 minor risk factors difficult to measure SFH (BMI >35, large fibroids)

Question 29

suggest the management of static growth

Answer 29

early delivery

Question 30

suggest the management of abnormal doppler results

Answer 30

early delivery (remove the foetus from the hostile uterus)

Question 31

which drugs are given when delivery is planned early? is this still true for cesaerean?

Answer 31

corticosteroids yes - it is especially the case for caesarean