Flashcards in multiple pregnancy Deck (21):
define monochorionic multiple pregnancy?
single placenta is shared by two or more fetuses
risk factors for multiple pregnancy?
assisted reproduction, increasing maternal age, increasing parity
what do we mean by dizygotic twins?
non-identical twins; two different eggs were fertilised and implanted into uterine wall--> 2 x placenta
what do we mean by monozygotic twins?
identical twins- one fertilised egg splits into two and implants into uterine wall
what are some maternal complications that we have to consider in multiple pregnancy
what does TTTS stand for in multiple pregnancy?
twin to twin tranfusion syndrome
what does TAPS stand for in multiple pregnancy?
twin anaemia polycythaemia sequence
which u/s is best to confirm twinning and their chorionicity and amnionicity?
first trimester u/s
in a mother carry dizygotic twins, what is risk of having one child affected by down's syndrome?
doubled risk bc each twin carries their own risk
how might we reduce the risk of pre-eclampsia in a woman carrying multiple pregnancies?
aspirin 100mg/day from 12-36 weeks
when might we trial vaginal delivery for a pregnant woman with twins?
if the first twin is in a vertex position may try to do a vaginal delivery, however low threshold for c-section in the case complications arise
after ___ weeks gestation, chorionicity in a multiple pregnancy becomes difficult to determine.. fill in the gap
14 weeks' gestation
what is the management of twin to twin transfusion sequence?
Laser ablation of vascular connections is the recommended treatment for the majority of pregnancies with TTTS that require intervention, and referral to a laser surgery facility should be considered - even where this would mean interstate transfer
Early referral is recommended to allow optimal treatment before the onset of severe disease and cervical shortening.
what is the risk of delivering term monochorionic monoamionic twins vaginally?
what defines chorionicity and amnionicity in multiple pregnancy?
Chorionicity and amnionicity is determined by timing of zygote cleavage
how do we determine the zygosity of a dichorionic multiple pregnancy seen on u/s?
Zygosity can only be reliably determined however if two different genders are seen on u/s
what is the sensitivity of combined screening for down's syndrome for multiple pregnancy?
Down's syndrome combined screening 75-85% sensitive in twins (U/s is better than maternal serum analytes in this case)
NIPS-> mixed pattern on cell free fetal DNA (but still quite sensitive)
what are some antenatal/intrapartum considerations for multiple pregnancy?
• Generally will go into spontaneous preterm labour
• Cervical cerclage +/- progesterone plessaries have NOT been shown to reduce preterm labour
• Advise women to stop smoking, treat asymptomatic bacteriuria
• Administer 100-150mg aspirin daily from < 16 weeks to prevent preeclampsia
• IM celestone +/- magnesium sulfate for neuroprotection in anticipation of preterm labour
Caesarean deliveries are more common than vaginal delivery however vaginal delivery may be possible if presentation appropriate
a lady with twins has her 20 week u/s and it shows:
Duodenal atresia- double bubble on u/s
What are you thinking and what are your management options?
--> Highly likely that this is T21
--> amniocentesis for each sac to diagnose T21
--> option of selective termination--> dependent on chorionicity
If dichorionic--> KCL into the heart --> fetal death in 60% but this leads to increased mortality of the surviving fetus in the early gestation period
Late termination for T21 is preferred at 36 weeks in this case but runs the risk of going into labour before termination can be performed
monochorionic twins are always....?
what about dichorionic twins?
monochorionic twins are always monozygotic identical twins
dichorionic twins can either be monozygotic or dizygotic but the chances are higher for dizygotic