Twin pregnancy Flashcards
Incidence of multiple pregnancy?
1 in 60 pregnancies
Of twins, how many are dichorionic and monochorionic ?
DC: 70%
MC: 30%
For a twin pregnancy, what do you see on the 1st trimester ultrasound?
Gestational age - determine GA from largest twin to avoid estimating it from a baby with early growth pathology
Chorionicity and amnionicity
Before 14 wks
Number of placental masses
Membrane thickness
Lambda & T sign
After 14 weeks
Additional - fetal sex
Lambda sign seen in ?
DCDA
T sign is seen in
MCDA
What if difficult to detect chorionicity or amnionicity ?
2nd opinion from senior or
Referral to a competent health-care professional
If still difficult after referral - manage as monochorionic
Due to high risk of anemia in multiple pregnancy, when do you perform an additional CBC apart from at booking and 28 wks ?
20-24 W
How many antenatal appointments for
DCDA twins ?
TCTA triplets ?
Twins or triplets with a shared chorion ?
Twins or triplets with a shared amnion ?
8
9
11
Shared amnion - Individualise from tertiary level fetal medicine unit
How do you screen for chromosomal anomalies in twins ?
Same as singleton
Maternal age + NT + Double marker or if late booking - Quad marker
How do you screen for chromosomal anomalies in triplets?
Maternal age + NT
No 2nd trimester serum markers
TriTri - fetus specific risk calculated
If high chance - refer to fetal medicine
For screening of dichorionic and monochorionic triplets- refer to fetal medicine
How many twin & triplet pregnancies have a spontaneous Preterm birth ?
60% before 37 wks for twins
75% before 35 wks for triplets
How is monitoring for FGR done ?
Can it be done in the 1st trimester ?
- SFH and abdominal palpation not used
- Ultrasound done
- 24 wks onwards - in TriTri and DiDi
Rest - from 16 wks onwards
Not in 1st trimester
