Multiple pregnancy & problems Flashcards
What is the natural rate for twinning?
1:90
Why is there an increased incidence in twinning?
Assisted reproductive techniques and ovulation induction
What does the incidence of dizygotic twins increase with?
Age, parity, weight, height, familial
When do you suspect multiple pregnancy?
Large for date uterine size Multiple fetal heart rates detected Multiple fetal parts felt HCG + maternal serum AFP elevated for gestational age Pregnancy with ART Confirmed with USS
What is monozygotic?
Twins derived from single ovum - so identical
What is dizygotic?
Twins derived from two separate ova - not identical
What is diamniotic?
Has its own amniotic sac
What is dichorionic?
Has own chorionic sac
What is a dichorionic, diamniotic pregnancy?
Where each twin has its own chorionic and amniotic sacs - most twins
What does monozygotic depend on?
Cleavage of single fertilized ova
What does placentation of monozygotic twins depend on?
Timing of cleavage determines placentation
What is the timing of cleavage for monzygotix dichorionic/diamniotic twins?
Cleavage in first 3 days after fertilisation
Each fetus has own placenta
Which type of placentation has lowest mortality rate of monozygotic twins?
Dichorionic/diamniotic
What is the timing of cleavage for monozygotic monochorionic/diamniotic twins?
Cleavage between day 4 and 8 after fertilisation
Share single placenta but seperate amniotic sac
What is the timing of cleavage for monozygotic monochorionic/monoamniotic twins?
Cleavage after the 8th day of fertilisation
Share single placenta and single sac
What day does cleavage happen in conjoined twins?
Cleavage after day 12
What is the most common way of conjoined twins being joined?
Chest and/or abdomen
What are complications of multiple pregnancy?
High perinatal mortality and morbidity Abortion Nausea & vomiting Preterm labour IUGR Pre-eclampsia Polyhydramnious Congenital anomalies PPH Placental abruption Placenta praevia Discordant twin growth Malpresentation, cord prolapse, operation delivery
What are some causes of perinatal mortality and morbidity?
Prematurity Birth trauma Cerebral haemorrhage Birth asphyxia Congenital anomalies Still birth
What is a twin-twin transfusion (TTN)?
One fetus donates blood to the other due to vascular anastomosis
What will happen to the recipient twin in TTN?
Heart failure, polyhydramnious and hydrops
What will happen to the donor twin in TTN?
IUGR and oligohydramnios
What is hydrops?
Hydropsfetalis, orhydrops, is a condition that occurs when large amounts of fluid build up in a baby’s tissues and organs causing extreme swelling
What is the management for TTN?
Amnio-reduction of recipient twin
Intra-uterine blood transfusion for the donor twin
Selective fetal reduction
Fetoscopic laser ablation of placental anastomosis
What is the antenatal management of multiple pregnancy?
Adequate nutrition
Prevent anaemia
More frequent antenatal visits
USS: assess chorionicity, nuchal translucency, fetal growth, fetal wellbeing
Multifetal reduction offered
Preterm labour risk: serial cervical length assessment, steroids for fetal lung maturation
What is the twin peak sign characteristic of on USS?
Dichorionic twins
What is the T sign characteristic of on USS?
Monochorionic twin
What is management of labour in multiple pregnancy?
First fetus cephalic - normal delivery Non vertex first - C-section Locked twins (breech-vertex) - C-section
What is the average pregnancy length for twins?
36-37wks
What is the average birth weight for twins?
2.5kg
What are some complications of multiple pregnancy?
Clubfoot Cleft lip/palate TTS Fetal growth problems Preterm labour
