Twin Gestation Flashcards
how is chorionicty determined? when?
via ultrasound during the first or early second trimester
t or f: multiple gestation pregnancy has a high incidence of preterm labor
true
management of antenatal care for a mother of twins should include what two tests/procedures?
ultrasound to determine chorionicity and serial ultrasounds to check for fetal growth restriction/discrepancy
how are dizygotic twins formed?
when two separate ova are fertilized by two separate sperm
how are monozygotic twins formed?
when one ovum is fertilized by one sperm and subsequently splits
how are the chorionicity and amnionicity of monozygotic twins determined?
by the timing of cell division
what is the time frame of cell division associated with dichorionic, diamniotic twins?
division between days 0 to 3
what is the time frame of cell division associated with monochorionic, diamniontic twins?
division between days 4 to 8
when does cell division occur in order to produce conjoined twins?
after 13 days
t or f: monochorionic twins have more complications than dichorionic twins
true
t or f: there is no increased risk for both structural and congenital anomalies with twin gestations
FALSE
what are some ddx for a size/date discrepancy in pregnancy? @ least 5
twins, distended bladder, fetal macrosomia, hydramnios, maternal obesity, uncertain LMP, molar pregnancy, adnexal mass
how often should monochorionic twins undergo US examination to examine fetal growth? dichorionic?
every 4 weeks; 6-8 weeks
what is twin to twin transfusion syndrome, and what kind of twins are most at risk?
condition in which blood/intravascular volume is shunted from one two to another leading to under-perfusion of one twin and over perfusion of the other (donor to recipient); monochorionic
what is the cause of TTTS?
unbalanced vascular anastomoses
