IVF/Twinning Flashcards
What is ART
assisted reproductive techniques
What are the main ARTs
IVF and ICSI
Preimplantation genetic diagnosis can be carried out
3-5 days after IVF, no later than 8 cell stage (cells are pluripotent)
fertilized eggs are implanted when they reach what stage
blastocyst
What is the most common risk of IVF
multifetal gestation (twins or more)
Twins that form by splitting of a single original embryo
monozygotic (identical)
twins that arise from separate oocytes produced during the same menstrual cycle
dizygotic (fraternal)
Dizygotic twins are always
dichorionic/diamniotic
What are the major complications of twin pregnancies
in utero death of one twin
TTTS
twin-reversed arterial perfusion (TRAP sequence)
cord entanglement
What happens in in utero death of one twin
the blood pressure of the dead twin drops significantly, the other twin may suffer heart failure as it attempts to fill both circulatory systems.
Other twin could also be killed by an embolism from breaking off of tissue of dead twin
What occurs in TRAP sequence
one twin provides all the blood flow to a second acardiac/acephalic twin. Causes death in 50-75% of cases.
Cord entanglement is most common complication in
monochorionic/monoamniotic twins
Triplets may be derived from what 3 occurrences?
one zygote and be identical
2 zygotes and have 1 set of identical twins and a singleton
3 zygotes and be of the same or different sexes
