L19 - Multiple Pregnancy COPY

Question 1

MULTIPLE PREGNANCY AETIOLOGY & EPIDEMIOLOGY

i) what type of egg release results in multiple pregnancy?
ii) give four things can contribute to someone being more likely to have a multiple pregnancy?
iii) why has >3 baby multiple pregnancy fallen in last 10 years?
iv) why has there been an increase in twins since 1978?
v) define zygosity, chorionicity and amnionicity

Answer 1

i) super ovulation
ii) ethnicity, increased maternal age, increased parity, FH, IVF
iii) laws to limit how many embryos can be put back in IVF
iv) IVF was introduced in 1978

v) zygosity - how many eggs
chorionicity - how many placentas
amnionicity - how many amniotic sacs

Question 2

MONOZYGOTIC TWINS

i) which type of chorionic/amniotic twins result from the embryo splitting early on (2 cell or blastocyst stage) and come from two seperate inner cell masses?
ii) which type of chorionic/amniotic twins result from the embryo splitting later on and come from one inner cell mass?

Answer 2

i) splitting in early stages > 2 ICMs
- dichorionic diamniotic
- monochroionic, diamniotic

ii) splitting later > 1 ICM
- monochorionic, monoamniotic

Question 3

DIAGNOSING TWIN PREGNANCY

i) give two ways which this can be done?
ii) what may be seen on imaging for dichorionic twins?
iii) what may be seen on imaging for monochorionic twins?

Answer 3

i) ultrasound or uterine size (if imaging now available)
ii) dichorionic - lamba sign
iii) monochori and diamni - T sign

Question 4

COMPLICATIONS

i) what may be seen, especially in the first trimester?
ii) how may blood be affected?
iii) how may BP be affected?
iv) how may baby growth be affected?
v) what may happen at time of delivery?

Answer 4

i) hyperemesis
ii) anaemia
iii) high BP
iv) interuterine growth restriction
v) pre term labour and delivery problems

Question 5

FIRST TRIMESTER MANAGEMENT

i) what should be discussed with parents?
ii) what should be determined? how is this done?
iii) what may need to be discussed if triplets or more?

Answer 5

i) screening for chromo abnormalities
ii) chorionicity - lamba (di) or T sign (mono)
iii) fetal reduction

Question 6

SECOND TRIMESTER MANAGEMENT

i) what scan takes place between 18-22 wks?
ii) which type of scans are just given to twins? what are these for?
iii) from what week do dichorionic twins get scanned monthly?
iv) between which weeks are monochorionic twins scanned twice weekly? if everything is ok then how often are they scanned after this?
v) which complication is scanned for in MC twins?

Answer 6

i) fetal anomaly scan
ii) serial scans for growth for all twins and for TTTS for MC twins
iii) from week 24
iv) MC twins scanned twice weekly 16-24 weeks then monthly if everything is ok
v) screen for twin to twin transfusion syndrome

Question 7

COMPLICATIONS IN MC TWIN PREGNANCY

i) name four things there is a higher risk of

Answer 7

i) miscarriage, fetal malformation, fetal growth restriction, twin to twin transfusion

Question 8

TWIN TO TWIN TRANSFUSION SYNDROME

i) what happens?
ii) why does this happen?
iii) how much blood does the donor twin and recipient twin recieve proportionally?
iv) which twin has a higher likelihood of mortality?
v) how can this be treated?
vi) how must the twins be delivered?

Answer 8

i) shunting in the umbilical cord branching leads to more blood going to one twin
ii) happens due to unbalanced placental vascular anatomoses

iii) donor twin = less blood
recipient twin = more blood

iv) recipient twin has higher likely mortality (lots of blood > HF)
v) laser abherrant vessels
vi) early caesearian

Question 9

THIRD TRIMESTER AND DELIVERY PLANNING

i) what needs to be monitored in the 3rd trimester especially?
ii) when should DC twins be delivered? can this be vaginal or will they need CS?
iii) what does delivery largely depend on?
iv) when should MC twins be delivered?

Answer 9

i) blood pressure

ii) 37-38 weeks
- can be vaginal

iii) delivery depends on how twin I is laying in the uterus
iv) 36-37 weeks

Question 10

LABOUR MANAGEMENT

i) how may baby I and baby 2 be managed? what is measured?
ii) why may there be a problem delivering twin 2? what can be done to help this?
iii) what is there risk of to the mother? why does this happen more in twin pregnancies?

Answer 10

i) baby 1 with fetal scalp electrode and twin 2 by CTG
- measure contractions and heart rate

ii) twin 2 may be high in the uterus
- squeeze abdomen to keep baby in a longitudinal position

iii) post partum bleeding
- more common with twins as usually uterus contracts down to stop bleeding but in twins its overstretched and may not be able to do this