T2 L15:Multiple pregnancies Flashcards
aetiology of twin pregnancy
2-7 Far East
9-20 Europe
20-45 Nigeria
incidence increased since 1980’s due to IVF treatment
Ethnicity
Increasing maternal age
Increasing parity-indicates the number of pregnancies reaching viable gestational age (including live births and stillbirths)
Family history
Fertility treatment
All factors for ‘super ovulation’
what are the 3 factors that are looked at in multiple pregnancies
Zygosity
Chorionicity
Amnionicity
explain the difference between monozygous dizygous
Monozygous = 1 egg = identical (1/3)
Dizygous = 2 eggs = nonidentical (2/3)
describe dizygotc twins
separate amnions, chorions & placentae
DCDA
describe the possible combinations of monozygotic twins
common chorion, separate amnions & “joined” placentae
MCDA
common chorion amnion, & “joined” placentae
MCMA
what gives rise to the difference between mcma and mcda twins and dizygotic twins
Mcda: -splitting in early blastocyst yields 2 inner cell masses -Blastocyst – 4 days after fertilisation, inner cell mass forms (forms part of embryo)
MCMA:
-Later splitting yields
2 embryos from one
inner cell mass
DCDA: -Splitting occurs very early (24 hours after fertilisation)-at 2 cell stage
what is the different combinations with dichorionic twins
All dizygous twins are dichorionic Dichorionic twins must be diamniotic Dichorionic = separate circulations 1:3 monozygous twins are dichorionic
what is the different combinations with monochorionic twins
Monozygous twins may be monochorionic (2/3) or dichorionic MC have vascularly joined placentae MC twins 3x increased loss rate MC twins usually diamniotic
how do you diagnose twin pregnancies
Uterine size
Up to 50% at delivery worldwide
Ultrasound
what does the Lambda sign denote
Dichorionic
what does an ultrasound tell
Whether its MA or DA
what does the T-sign denote
T sign –MONOCHRONIONIC BC NO LAMDA SIGN- ( LAMDA IS A SIGN OF DIFF PLACENTAS
what are the complications with twin pregnancies
“Everything except post-dates” Symptoms of pregnancy Anaemia Hypertension Intrauterine growth restriction Pre-term labour Delivery problems Perinatal mortality
twin pregnancy mortality
Stillbirth – after 24 weeks Early neonatal – first 7 days Neonatal – in first 28 days Perinatal – SB + early neonatal Infant – first year Rates are per 1000 births
how do you manage the first trimester
- Discuss screening for chromosomal anomalies
- Determine chorionicity
- Discuss fetal reduction if triplets or more
what is second trimester management
-Detection of fetal abnormality
-Serial scans for growth for all
DC monthly from 24 weeks
-Serial scans for TTTS if MC twins
2 weekly 16-28 weeks then monthly
-Maternal complications
what risks are specific to monochorionic twins
- More fetal malformation
- More fetal growth restriction
- Twin to twin transfusion
look at slides for quizzes 29-38
How was it?
what does Unidirectionality A-V shunt in twin-twin transfusion, cause ?
Can cause heart failure in fetus receiving too much blood
- Unbalanced placental vascular anastamoses
- Donor smaller, decreased liquor
- High mortality (esp recipient)
how do you treat twin-twin transfusion
Laser treatment:
Rx - laser or amnio-reduction
Early delivery by caesarean
slide 50
how was it
what is the 3rd trimester management
- Scanning as in 2nd trimester
- Monitor blood pressure
- Pre-term labour
- Delivery planning
what are the delivery plans for twins
- 37-38 weeks for DC twins
- -vaginal birth or caesarean
-Presentation of twin 1
- 36-37 weeks for MC twins
- -?all MC twins by caesarean?
what is the labour management of twin pregnancy & monitoring method
- Monitoring both twins
- Problems delivering twin 2
- Risk of postpartum bleed
- Monitoring- via fetal calp electrode for first baby and the other monitored externally
what are the puerperium management
-Feeding difficulties
Emotional & social support
