Placenta And Umbilical Cord Flashcards
Time of implantation of the blastocyst in the endometrium
5th to 6th day post fertlization
Definitive placenta is seen at how many weeks post fertilization?
10-12 weeks
With true maternal blood flow established at 12 weeks AOG
Placental Development:
Hyperechoic rim surrounding gestational sac
10 weeks AOG
12-13 wks intervillous blood flow
14-15 wks retroplacental complex (hypoechoic area beneath placenta)
16-18 wks small intraplacental arteries
Most common cause of 3rd trimester PAINLESS vaginal bleeding
Placenta Previa
Placenta reaches the edge but does not cover the internal OS
Marginal previa
Placental edge within 2 cm from the internal Os
Low-lying placenta
Most common tumor of the placenta supplied by fetal circulation
Chorioangioma
Umbilical cord is positioned between the presenting fetal part and cervix
Vasa previa
Umbilical cord positioned in front of the presenting fetal part near endocervical Os that CHANGES in position with change of maternal position.
Funic presentation
Abnormal adherence of placenta penetrating the decidua but NOT the myometrium
Placenta Accreta
Increta = penetrate the myometrium
Percreta = extends to serosa or adjacent organs
Most predictive sonographic sign of accreta
Presence of placental lacunae in the myometrium
Most common abnormality of the umbilical cord
Single umbilical artery
Exaggerated eccentric insertion of the umbilical cord at the placental margin
Battledore Placenta
Umbilical insertion beyond the placental edge into the free placental membrane
Velamentous Cord Insertion
Commonly seen in Monochorionic twin
Most common tumor of the umbilical cord
Hemangioma
