Multifetal Gestation and Malpresentation Flashcards
What is the avg age of delivery for twins, triplets, and quads
Twins = 35 wks Triplets = 32 wks Quads = 30 wks
How are Fraternal twins formed
2 ova and 2 sperm (Dizygotic)
What factors influence incidence of dizygotic twins
Maternal age (2x increase > 35 yo)
FH
Ethnicity
What sign will Dizygotic twins show on US
“Peak” or “Inverted V”
B/w what days do dichorionic diamniotic twins cleave
0-3 days
B/w what days do monochorionic diamniotic twins cleave
4-8 days
B/w what days do monochorionic monoamniotic twins cleave
9-12 days
After what day do conjoined twins cleave
> 13 days
Which type of monozygotic twinning is most common and which is most dangerous
Common = Monochorionic Diamniotic Dangerous = Monochorionic Monochorionic
How do ACARDIAC twins form
Arterial-Arterial malformations causing one twin to be transfused in reverse direction
What would an ACARDIAC twin look like
Developed LE’s but no ab or cephalic structures
Def = umbilical cord attaches at a site distant form the placenta
Velamentous umbilical cord
If one twin fetus dies at < 12 wks gestation, what happens to it
Gets reabsorbed (vanishing twin)
If one twin fetus dies at > 20 wks gestation, what happens to it
Is retained in the uterus
If one twin fetus dies b/w 12-20 wks gestation, what happens to it
Becomes Fetus Papyraceus
How often are prenatal visits for the 1st/2nd trimesters during twin pregnancies
Visits q 2 wks
At what point in the twin pregnancy does the mother get put on bed rest
3rd trimester
At what gestational age are monoamniotic twins delivered
32 wks
Def = any presentation other than vertex
Malpresentation
What are the criteria needed to allow a breech delivery
> 37 wks Frank/Complete B/w 2500-4000g Head flexed Adequate maternal pelvis
Who are candidates for external cephalic version
Pts > 36 wks not in labor
When is it ok to deliver a baby in the “face” presentation
If the head is fully extended and the mentum is anterior
