TWINNS Flashcards
twins born what week
37
trips born what week
34
quads born what week
33
Fetal mortality rates are _____X that of singleton pregnancies
3-6X
Neonatal mortality _____X that of single pregnancies.
7X
why does multiple have higher fatality
Primarily due to much higher incidence of premature labour.
Increased chance of dizygotic twins if:
increased maternal age frequent pregnancies pregnancy techniques -> hormone stimulation heredity -> mom is a twin race-> african
if there is a single outer membrane the twins must be
monozygotic
1/3 of monozygotic twins are
dichorionic/diamniotic
two types of DCDA
seperated and fused
0-4 days for split =
DCDA
8-13 days =
MCMA
why is chorionicity important
Monochorionic twin pregnancies have 3-5 times higher risk of perinatal mortality and morbidity than Dichorionic
Chorionicity best evaluated in ___ trimester
1st
Di chorion gives what sign
twin peak (lambda sign)
how many yolk sacs in monochorionic
1 usually
3 primary complications of multifetal pregnancies
Premature delivery
IUGR
Demise of a co-twin
2 risks closely related to monochorionicity
congenital malformations and congenital heart disease
since monochorionic twin pregnancies share the one placenta the are prone to
haemodynamic complications
main monoamniotic complication
entangled cords
what is twin growth discordance
refers to a significant size or weight difference between the two fetuses of atwin pregnancy
To be classified as a growth discordance:
Weight discordance (weight disparity of greater than 15-25%)
Some consider that the estimated fetal weight (EFW)
of the smaller twin should fall under the 10thpercentile.
weight % difference equation
(Larger twin EFW – Smaller Twin EFW) / Larger twin EFW * 100
intra uterine growth restriction (IUGR) characterized by
impaired fetal growth and inadequate placental function
the greater the discordance the higher the likelyhood of (4)
Placental insufficiency
Twin-twin transfusion syndrome
Higher incidence with avelamentous cord insertion
Higher incidence with asingle umbilical artery
growth differences most profound > ____ _weeks
> 30 weeks
A weight discordance is assessed by taking the estimated fetal weight (EFW) difference at ___-____%
15-25%
twin to twin transfusion occurs in twins that are
identical twins that are monochorionic, diamniotic.
what happens in twin to twin transfusion
single placenta contains blood vessel connections between the twins.
is twin to twin transfusion genetic or from trauma
no
what is the result of the twin getting too much blood
increase urine production and will have distended bladder as well as too much amniotic fluid around it (polyhdramnios)
what happens to the donor twin
twin will produce less than the usual amount of urine. The amniotic fluid around the donor twin will become very low or absent (oligohydramnios).
what is a stuck twin
the donor twin becoming wrapped in amniotic membrane becuase there is no fluid around it
alternative term for twin to twin transfusion is
Twin Oligohydramnios/polyhydramnios syndrome
what is Twin Reversed Arterial Perfusion sequence (TRAP)
A late separation of the embryonic cell mass results in a monochorionic-diamniotic twin pregnancy.
Anastomosis of vessels establishes a connection between the 2 circulations (unbalanced AA anastomosis).
Retrograde perfusion interferes with normal cardiac development, which rarely goes beyond the stage of tubular heart.
Thus the acardiac fetus becomes dependent on the perfusion of the “pump” twin.
what happens to the acardiac twin
lower half of body better developed but upper half not at much
Twin Reversed Arterial Perfusion sequence (TRAP) occurs in what type of twin
monochorionic-diamniotic
acardiac twin is really just a
parasite (TOUGH LIFE) lol
the pump twin in TRAP is at risk for
high output cardiac failure
