Flashcards in Twin Gestations Deck (14)
Rate of twins
3.3% of all live births
If monozygotic twins cleave in first 0-4 days after fert you get
Dichorionic diamniotic twin
2 morula --> 2 blastocysts in own layer of trophoblast cells --> own chorion --> own amnion
If monozygotic twins cleave in 4-8 days after fert you get
monochorionic diamniotic twin
*most common of the monozygotic twins (75%)
If monozygotic twins cleave in 8-12 days after fert you get
monochorionic monoamniotic twin
How many twin pregnancies are conceived spontaneously?
Risk of twin pregnancies (12)
2. Hyperemesis (high hCG)
3. high risk of aneuploidy and anomalies
4. Prenatal screening tests less sensitive and diagnostic procedures more difficult
5. Maternal anemia
6. Gestational diabetes ( high hPL)
7. Gestational hypertension/preeclamsia
8. Intrauterine growth restrictions
9. Preterm birth (~36 weeks)
10. Higher rate of Cesarean delivery
11. Postpartum hemorrhage
12. High perinatal mortality (first week)
Twin twin transfusion syndrome
- what is it?
- What does the recipient twin do?
- What does the Donor twin do?
20% of mo-di twins have unbalanced flow through connected vessels
1. Recipient twin (larger)
- increases urine production to reduce blood volume
2. Donor twin (smaller)
- Reduces urine production to retain blood volume
When do you have to treat TTTS by?
Prior to 24 weeks or else mortality of one or both twins in 80-90% of cases
WHAT causes death of donor twin
decreased blood vol --> lower Urinary output to maintain blood vol --> oligohydramnios --> shunt away nutrients and cant support fetal growth
What causes death of recip twin
getting too much bv --> huge strain on babys heart (HF) --> too much urine prod --> polyhydramnios --> uterine distention and early deliver
- sometimes fetal hydrops
Twin peak/ Lamda sign = ?
Thick dividing membrane = DI Di
- 0-4 days
T sign ?
- 4-8 days
TTTS, which twin is smaller, which is larger?
Recipient twin is larger
DOnor twin is smaller