Ultrasound Imaging in Multifetal Pregnancies

53 Pages·2013·3.53 MB·English

by  Anthony Johnson

“Ultrasound Imaging in
Multifetal Pregnancies:
Its More than Chorionicity”
Anthony Johnson, DO
Professor, UTHSC, Houston, TX
Co-Director, Texas Fetal Center, CMHH
1
Disclosures
• I have no relationships with commercial companies
that could be perceived as a conflict of interest.

• I will not be discussing the use of products that are
investigational or approved devices that are being
used “off label
”
Perinatal mortality
MC vs. DC twins
Dutch cohort study 1995-2004

Outcome MC DC Hazard Risk
(n = 198) (1107) (95%CI)
Perinatal 11.6% 5.0% 2.44
Mortality (1.73-3.44)
Stillbirth 7.6% 1.5% 5.21
(3.18-8.51)
Screening protocol:
-  1st trimester ultrasound for chorionicity
-  20 wks anatomic survey
-  Serial ultrasounds (fortnightly) for growth, AFV and Doppler assessment
Hack KEA et al BJOG 2008;115:58-67
Outcome of MCDA twin gestations in the
era of invasive fetal therapy

Survival
Twin live births 172 85%
Singleton 15 7%
Double demise 15 7%
Complication
TTTS 18 9%
sIUGR 30 15%
Losses
Total 11% (TTTS ~ 42%)
< 24 weeks 84%
> 24 weeks 16%
> 32 weeks 1%
Extra loss in MC twins is due to complications placental anastomoses
Lewi et al., 2008
Complications in Monochorionic
Multi-Fetal Pregnancies
Twin-Twin Transfusion Syndrome
• 
- Oligo/Polyhydramnios Sequence ~ TOPS
- Twin Anemia Polycythemia Sequence ~ TAPS
•  Twin Reverse Arterial Perfusion

•  Growth Discordance

•  Discordant malformations

-  Structural
-  Chromosomal
•  Monoamnioitc
Diagnosis
There is NO diagnosis of twins.”
"
“The only diagnosis is a monochorionic or
dichorionic twin gestation.

This should be written in capital red letters
on the front of the chart at 8 - 10 weeks".

K Nicolaides, 02/27/09
Multifetal Pregnancies
Ultrasound Determination of
Amnionicity & Chorionicity
1st Trimester Ultrasound Examination:
-  Amnionicity and chorionicity should be documented for all
multiple gestations when possible.

2nd & 3rd Trimester Ultrasound Examination:
-  Multiple gestations require the documentation of additional
information: chorionicity, amnionicity, comparison of fetal
sizes, estimation of amniotic fluid volume on each side of
the membrane, and fetal genitalia (when visualized).

AIUM PRACTICE GUIDELINES, Oct 2007
ACOG PRACTICE GUIDELINES, #101, Reaffirmed 2011
Ultrasound techniques for determining
chorionicity & amnionicity
Umbilical cord entanglement
Fetal sex
Separate placental discs
No. of layers in membrane
Membrane thickness
Lambda or Twin Peaks or T-sign
No. of yolk sacs
amnionicity
No. of gestational sacs chorionicity
First trimester Second Trimester Third Trimester
J Robinson & AZ Abuhamad Modern Medicine 2002
Multifetal Pregnancies
Chorionicity
Monochorionic
Dichorionic
“T” sign
Lambda or Twin Peak sign
Moise KJ Texas Medicine 2007