Multiple Pregnancy Flashcards
Multiple pregnancy
Refers to a pregnancy with more than one fetus.
Monozygotic
Identical twins (from a single zygote)
Dizygotic
Non-identical (from two different zygotes)
Monochorionic
Share a single placenta
Dichorionic
Two separate placentas
What conditions give the best outcome
Diamniotic, dichorionic twin pregnancies
How is a multiple pregnancy diagnosed
Diagnosed on the booking ultrasound scan.
USS can be used to determine the:
- Gestational age
- Number of placentas (chorionicity) and amniotic sacs (amnionicity)
- Risk of Down’s syndrome (as part of the combined test)
How do dichorionic diamniotic twins present on USS
Have a membrane between the twins, with a lambda sign or twin peak sign
How do monochorionic diamniotic twins present on USS
Have a membrane between the twins, with a T sign
How do Monochorionic monoamniotic twins present on USS
Have no membrane separating the twins
Risks of a multiple pregnancy to the mother
Anaemia Polyhydramnios Hypertension Malpresentation Spontaneous preterm birth Instrumental delivery or caesarean Postpartum haemorrhage
Risks of a multiple pregnancy on the fetus
Miscarriage Stillbirth Fetal growth restriction Prematurity Twin-twin transfusion syndrome Twin anaemia polycythaemia sequence Congenital abnormalities
Twin-Twin Transfusion Syndrome pathophysiology
When the foetuses share a placenta, one fetus (the recipient) may receive the majority of blood from the placenta while the other fetus (the donor) is starved
What happens to the recipient in twin to twin transfusion
The recipient can become fluid overload
- Heart failure
- polyhydramnios
- large size
What happens to the donor in twin to twin transfusion
Growth restriction
Oligohydramnios
Anaemia
Small size
Management of twin to twin transfusion
Referred to specialist fetal medicine centre
Severe - laser treatment to destroy the connection between the 2 blood supplies
Twin Anaemia Polycythaemia Sequence
One twin becomes anaemic whilst the other develops polycythaemia (raised haemoglobin)
More gradual
Monitoring for multiple pregnancies
Additional ultrasound scans:
- 2 weekly scans from 16 weeks for monochorionic twins
- 4 weekly scans from 20 weeks for dichorionic twins
Planned birth for multiple pregnancy
Planned birth is offered between:
32 - 33 + 6 weeks for uncomplicated monochorionic monoamniotic twins
36 - 36 + 6 weeks for uncomplicated monochorionic diamniotic twins
37 and 37 + 6 weeks for uncomplicated dichorionic diamniotic twins
Before 35 + 6 weeks for triplets
What is given before the birth in a multiple pregnancy
Corticosteroids
Monoamniotic twins delivery
Require elective caesarean section at between 32 and 33 + 6 weeks
Diamniotic twins delivery
Vaginal delivery - possible when the first baby has a cephalic presentation
Caesarean section - may be required for the second baby
Elective caesarean - advised when the presenting twin is not cephalic presentation
