Multiple pregnancy Flashcards
What are monozygous twins?
Division of a fertilised egg so you have:
IDENTICAL TWINS
What percentage of twins are monozygotics?
20%
What are dizygous twins?
two eggs fertilised by 2 different sperm
NON IDENTICAL
What does chorionicity mean?
Chorionicity: Number of placentas in the multiple pregnancy
Can be:
Monochorionic = sharing single placenta
Dichorionic = two separate placenta
What does it mean by dichorionic?
Two seperate placentas
Which type of chorionicity can cause twin-twin transfusion syndrome?
Monochorionic
= one fetus (recipient) with recieve the majority of placental blood wilst other (donor) is starved
discrepancy in baby size
In twin-twin transfusion syndrome what impact can it have on the recipient?
Recipient : fluid overloaded, heart failure and polyhydramnios
In twin-twin transfusion syndrome what impact can it have on the donor?
Donor: growth restriction, anaemia and oligohydramnios
How is twin-twin transfusion syndrome treated?
= laser ablation to destroy connection between the two blood supplies
The timing of the zygote splitting has an impact on the twins
<day 4?
<day 4 = DCDA (dichorionic diamniotic)
day 4 - 8 = MCDA (monochorionic, diamniotic)
day 8 - 12 = MCMA (monochorionic, monoamniotic)
> day 13 = conjoined twins
What types of amniocity are there?
Monoamniotic : single amniotic sac
or
Diamniotic : two seperate amniotic sacs
The timing of the zygote splitting has an impact on the twins
day 4 - 8 ?
<day 4 = DCDA (dichorionic diamniotic)
**day 4 - 8 = MCDA (monochorionic, diamniotic) **
day 8 - 12 = MCMA (monochorionic, monoamniotic)
> day 13 = conjoined twins
The timing of the zygote splitting has an impact on the twins
day 8 - 12 ?
<day 4 = DCDA (dichorionic diamniotic)
day 4 - 8 = MCDA (monochorionic, diamniotic)
**
day 8 - 12 = MCMA (monochorionic, monoamniotic)**
> day 13 = conjoined twins
Tags
The timing of the zygote splitting has an impact on the twins
day 13+ ?
<day 4 = DCDA (dichorionic diamniotic)
day 4 - 8 = MCDA (monochorionic, diamniotic)
**
day 8 - 12 = MCMA (monochorionic, monoamniotic)**
> day 13 = conjoined twins
Risk factors of having twins?
Advanced maternal age
OVF
Previous multiple pregnancy
Statistical prevalence of twin pregnancy?
1/80
gotta more cautious than in singleton pregnancy
Air travel and multiple pregnancy?
Avoid travel once 32+ weeks
singleton : 37 weeks
Signs of multiple pregnancy in 1st trimester?
3 signs
Incidental USS findings
Hyperemesis
Increased bHCG
Signs of multiple pregnancy in 2nd trimester?
think signs in later pregnancy
Large for dates
Multiple foetal parts on abdo exam
Pregnant abdominal examination for multiple pregnancy findings
3 signs
Increased symphysical fundal height
Multiple foetal parts
More than one heart beat
Ultrasound sign for dichorionic diamniotic twins?
LAMDA sign = showing the membrane between the twins
Ultrasound sign for monochorionic diamniotic twins?
T sign
Specific bloods for multiple pregnancies?
FBC at 20 weeks
AND
repeat at 28 weeks
Due to the increased risk of anaemia
Serial growth and doppler US for multiple pregnancies for monochorionic and dichorionic
Monitoring for IUGR and TTTS
Monochorionic : 2 weekly scans from 16 week onwards
Dichorionic : 4 weekly scans from 20 weeks onwards
The scans between w16-w24 for TTTS
24 weeks onwards for IUGR
