8.11 Multiple Pregnancy Flashcards
What does monozygotic twins mean?
Monozygotic: identical twins (from a single zygote)
What does dizygotic twins mean?
Dizygotic: non-identical (from two different zygotes)
What does monoamniotic twins mean?
Monoamniotic: single amniotic sac
What does diamniotic twins mean?
Diamniotic: two separate amniotic sacs
What does monochorionic twins mean?
Monochorionic: share a single placenta
What does dichorionic twins mean?
Dichorionic: two separate placentas
What type of twins have the best outcomes?
diamniotic, dichorionic - each have their own nutrient supply
What feature identifies dichorionic diamniotic twins on US scan?
they have a membrane between the twins:
“LAMBDA sign or twin peak sign”
What feature identifies monochorionic diamniotic twins on US scan?
they have a membrane between the twins:
with a “T-sign”
What feature identifies dichorionic diamniotic twins on US scan?
no membrane separating the twins
What are the risks of twins to the mother?
- anaemia
- polyhydramnios
- hypertension
- malpresentation
- spontaneous preterm birth
- instrumental delivery / caesarean
- postpartum haemorrhage
What are the risks of being a twin?
- miscarriage
- stillbirth
- FGR
- prem
- twin-twin transfusion syndrome
- twin anaemia polycythaemia sequence
- congenital abnormalities
What is another name for twin-twin transfusion syndrome?
feto-fetal transfusion syndrome
What happens / causes in twin-twin transfusion syndrome?
The twins share a placenta.
Recipient fetus receives majority of blood, whilst donor fetus is starved of blood.
What happens to a the recipient twin in feto-fetal transfusion syndrome?
Can become fluid overloaded; heart failure and polyhydramnios.
What happens to a the donor twin in feto-fetal transfusion syndrome?
Donor can have growth restriction, anaemia and oligohydramnios.
What is twin anaemia polycythaemia sequence?
Similar to twin-twin transfusion syndrome but less acute:
one twin becomes anaemic whilst the other is polycythaemic (raised Hb)
Mum carrying twins get which extra bloods tests and when?
Additional FBC monitoring for anaemia at:
- booking, 20 weeks, 28 weeks
Twins get extra scans for FGR, unequal growth and twin-twin transfusion syndrome, when?
- 2 weekly scans from 16 weeks for monochorionic twins
- 4 weekly scan from 20 weeks for dichorionic twins
Twins pregnancies are offered planned births between which dates depending on the type of twin?
Between:
32 and 33+6 for uncomplicated monochorionic monoamniotic twins
36 and 36+6 for uncomplicated monochorionic diamniotic twins
37 and 37+6 weeks for uncomplicated dichorionic diamniotic twins
before 35+6 for triplets
How can twins be delivered?
Monoamniotic twins require elective c-section (between 32 and 33+6 weeks)
Diamniotic - vaginal if 1st baby is in cephalic position.
