Multiple Gestation Flashcards
What does zigosity refer to?
Number of fertilized eggs
What does chorionicity refer to?
number of placenta
What does amniocity refer to?
Amniotic sacs
What percent of Monochorionic Diamniotic result in TTTS?
10%
What is the mortality rate with Mono-Mono Twins?
20%
For Di-Di twins: What is the days of zygote division?
Day 2-3
What percent of twins are Di-Di?
25%
For Mono-Di twins: What is the days of zygote division?
Day 4-7
What percent of twins are mono-Di?
75%
For Mono-Mono twins: What is the days of zygote division?
8 - 12%
What percent of twins are mono-mono?
1-2%
What gestational age is it best to determine chorionicity and amnionicity?
6-8 weeks
In general the number of yolk sacs is equal to the number of ____
Amniotic sacs 6
What characteristic findings on US do you see with Di-Di Twins?
Lamda, Twin peak sign
What characteristic findings on US do you see with Mono-Di Twins?
T sign
How does the rate of preE change with twin gestation?
3 fold higher in twin pregnancy
GA matched twins have a ___ fold increase in CP than singletons
4 fold
When should you start serial growth evaluation for Dichorionic twins?
24 weeks
How often should you monitor growth in Dichorionic twins?
q 4-6 weeks
When should you start serial growth evaluation for Monochorionic twins?
16 weeks
How often should you monitor growth Monochorionic twins?
q 2 weeks
True or false: Antenatal testing does not improve outcomes in uncomplicated dichorionic twins and thus is not indicated
True
Is discordance an indication for fetal testing in Di-Di TIUP if both twins are AGA
No
When is Antenatal testing indicated in twin gestations?
All monochorionic pregnancies
When should Antenatal testing start for mono-Di Pregnancies
32 weeks
When should you deliver Di-Di Twins?
38.0 - 38.6
When should you deliver Mono-Di Twins?
34.0 - 37.6
When should deliver Mono-Mono Twins?
32.0 - 34.0
How should you deliver mono- mono twins?
Cesarean section
What gestational age can you consider a vaginal delivery?
> 32wga
What is the baseline risk for fetal malformations in SIUP pregnancies?
2-5%
What is the risk of fetal malformations in twin pregnancies
4-10%
What is the rate of vanishing twin in di-di twins in the first trimester?
20%
What is the rate of vanishing twin in the second trimester for Di-Di twins?
2-5%
True or False: A vanishing twin decreases the risk of PTB and mortality for remaining twin
True
In the setting of IUFD of one twin in Monochorionic what are the major risk factors for the surviving twin?
Neurologic injury, Multi-organ damage
True or false: With IUFD of one twin in a monochorionic pregnancy immediate delivery of the other twin is indicated
False
What is the definition of discordance in the setting of TIUP?
EFW difference of > 20%
in what percentage of Mono di pregnancies does TTTS occur?
10%
What are the two criteria for diagnosing TTTS?
- Monochorionic, Diamniotic pregnancy
2. MVP > 8 in one fetus and MVP < 2 in other fetus
What is the definition of Stage 1 TTTS based on Quintero staging?
Amniotic Fluid, MVP > 8 and < 2
What is the definition of Stage 2 TTTS based on Quintero staging?
Absent bladder of donor twin
What is the definition of Stage 3 TTTS based on Quintero staging?
Abnormal dopplers, AEDF or REDF
What is the definition of Stage 4 TTTS based on Quintero staging?
Hydrops in one or both twins
What is the definition of Stage 5 TTTS based on Quintero staging?
Fetal Death
How do you manage stage 1 TTTS?
Expectant
What percentage of stage 1 TTTS will progress to a higher stage?
15%
How do you manage stage II - IV TTTS if less than 26 wga?
fetoscopic laser photocoagulation of placental anastomoses
How do you manage stage II - IV TTTS if greater than 26 wga?
Delivery
What is the rate of fetal mortality in monoamniotic twins?
10 - 20%
When do you start fetal surveillance for Mono-Mono TIUP?
24 - 28 wga
When do you delivery mono- mono TIUP
32 - 34wga
