Large for Dates

Question 1

What defines a large for date baby?

Answer 1

symphyseal-fundal height >2cm for gestational age

Question 2

What can cause a large for date baby?

Answer 2

fetal macrosomia
polyhydraminos
diabetes
multiple pregnancy

Question 3

How is fetal macrosomia diagnosed?

Answer 3

on ultrasound

• estimated fetal weight >90th centile
• estimated abdominal circumference >97th centile

Question 4

What are the risks of fetal macrosomia?

Answer 4

clinician and maternal anxiety
labour dystocia - difficult birth
shoulder dystocia - more common in diabetics - anterior shoulder gets caught above the mothers pubic bone
post partum haemorrhage

Question 5

How do you manage fetal macrosomia?

Answer 5

exclude diabetes
reassure
c/section if baby >4.5kg

Question 6

What is polyhydraminos?

Answer 6

excess amniotic fluid

Question 7

How is polyhydraminos defined?

Answer 7

amniotic fluid index >25mm

deepest pool >8cm

Question 8

What causes polyhydraminos?

Answer 8

maternal diabetes - most common
idiopathic - 2nd most common
fetal anomaly - GI atresia, cardiac, tumours
monochorionic twin pregnancy
hydrops fetalis
viral infection

Question 9

How does polyhydraminos present?

Answer 9

abdo discomfort
pre labour rupture of the membranes
preterm labour
cord prolapse

Question 10

What are the signs of polyhydraminos?

Answer 10

large for date
malpresentation
acute shiny abdomen
inability to feel foetal parts

Question 11

How is polyhydraminos diagnosed?

Answer 11

USS for AFI and DP

Question 12

What investigations should be done for polyhydraminos?

Answer 12

OGTT - to exclude diabetes
serology - toxoplasmosis, CMV, parvovirus
antibody screen

Question 13

How is polyhydraminos managed?

Answer 13

induce labour by 40 weeks

serial ultrasounds

Question 14

What’re the risks of polyhydraminos?

Answer 14

malpresentation
cord prolapse
preterm labour (before 37 weeks)
PPH

Question 15

What are the spontaneous risks of twins and triplets?

Answer 15

twins = 1 in 80

triplets 1 in 10,000

Question 16

What increases your chances of having multiple pregnancies?

Answer 16

assisted conception
race - african more common
family history
increased maternal age
increased parity
tall women >short women

Question 17

What is more common - dizygotic or monozygotic?

Answer 17

dizygotic - 70%

Question 18

What are dizygotic twins?

Answer 18

fertilisation of two ova by two sperm

Question 19

What are monozygotic twins?

Answer 19

splitting of a single fertilised egg

Question 20

What are the two types of chorionicity?

Answer 20

dizygotic chorionic - 1 placenta (dichorionic diamniotic DCDA)
monozygotic chorionic - 2 placentas - can be MCMA, MCDA o

Question 21

What do DCDA twins come from?

Answer 21

morula

day 0-3 after implantation

Question 22

What do MCMA twins come from?

Answer 22

implanted blastocyst

day 8-14 after implantation

Question 23

What do MCDA twins come from?

Answer 23

blastocyst

day 4-7 after implantation

Question 24

How is chorionicity determined?

Answer 24

ultrasound

Question 25

What do dizygotic chorionic look like on USS?

Answer 25

lambda sign

Question 26

What do monozygotic chorionic look like on USS?

Answer 26

T sign

Question 27

What type of twins are at highest risk of pregnancy complications?

Answer 27

MCMA and MCDA

Question 28

What are the symptoms of multiple pregnancy?

Answer 28

exaggerated pregnancy symptoms - ie sickness

Question 29

What are the signs of multiple pregnancy?

Answer 29

high AFP large for dates uterus multiple foetal poles

Question 30

When are multiple pregnancies confirmed on USS?

Answer 30

12 weeks

Question 31

What are the foetal complications that may occur due to multiple pregnancy?

Answer 31

congenital abnormalities eg acardiac twin intrauterine death growth restriction - both or disconcordant cerebral palsy - twinsx8 higher, tripletsx4 higher twin-twin transfusion - oligohrydroaminos+polyhydraminos

Question 32

What are the maternal complications that may occur due to multiple pregnancies?

Answer 32

``` hyperemesis gravidarum anaemia pre eclampsia antepartum haemorrhage preterm labour cesarean section ```

Question 33

How does the antenatal management of monochorionic twins differ?

Answer 33

clinic appointments every 2 weeks | ultrasounds 2 weekly from 16/40

Question 34

How does the antenatal management of dichorionic twins differ?

Answer 34

clinic appointments every 4 weeks | ultrasounds every 4 weeks

Question 35

What are monochorionic twin complications?

Answer 35

``` single fetal death selective growth restriction twin to twin transfusion syndrome (TTTS) twin anaemia - polycythermia sequence (TAPS) absend EDV or reversed EDV ```

Question 36

What is twin to twin transfusion syndrome (TTTS)?

Answer 36

syndrome with artery-vein astamoses | donor twin perfuses the recipient twin

Question 37

When should DCDA twins be delivered?

Answer 37

37-38 weeks

Question 38

When should MCDA twins be delivered?

Answer 38

after 36+0 weeks with STEROIDS

Question 39

How should MCMA, triplets etc be delivered?

Answer 39

c/section

Question 40

What time should be aimed for between twins birth?

Answer 40

<30mins | syntocinon after twin 1