Module 16 - Placenta & GTN Flashcards
How is the placenta graded?
Grade 0, I, II, II
0 being best, III being worst
What is considered placentamegaly?
> 4cm thick
Name 3 causes of placentamegaly
- maternal diabetes
- maternal anemia
- hydrops
- placental hemorrhage
- intrauterine infection
- partial mole
- chromosomal abnormalities
What is considered a thin placenta?
<1.5cm
Anechoic structures within the placental parenchyma
Placental lakes
Low lying placenta, <2cm from the internal os
Low lying placenta
Placenta touches the internal os
Partial placenta previa
Placenta completely covers the internal os
Complete placenta previa
Accessory lobe of the placenta
Succenturiate
Battledore umbilical cord insertion
<2cm from placental edge
Velamentous insertion
Cord inserts into chorionic membranes
Teratoma, chorioangioma
Tumours of the placenta
Describe the following: Accreta, increta, percreta?
Accreta: attaches to myometrium
Increta: invades into the myometrium
Percreta: invades through the myometrium
What is the function of the trophoblast?
Gain access to maternal circulation
Abnormal proliferation of pregnancy related trophoblast that can become malignant
Molar pregnancy
Most common form of GTN
Complete molar pregnancy
Karyotype of a complete mole
46xx or 46yy usually
Can be 46xy if it is fertilized by 2 sperm
How does a complete mole come to be?
Ovum lacking chromosomes is fertilized by normal sperm, causing the paternal chromosomes to duplicate
What are the major signs and symptoms of molar pregnancy?
Large for dates uterus, passing of grape-like tissue (hydropic villi), extremely high hCG levels, extreme nausea, pre-eclampsia
What is the karyotype of a partial molar pregnancy?
Triploidy. 69xxx, 69xxy or 69xyy
How do partial moles come to be?
One set of maternal chromosomes fertilized by 2 sets of paternal chromosomes OR ovum with duplicated chromosomes fertilized by 1 sperm
Invasive mole and choriocarcinoma are referred to as what?
Persistent trophoblastic neoplasia (PTN)
How long after a molar pregnancy is a woman advised to avoid conceiving again?
1 year
