Placenta Praeiva | The University Of Western Ontario

University:
The University Of Western Ontario
Course:
ANAT 2200B | Systemic Anatomy of the Human Body
Academic year:

2022
Views:

205

Pages:

3
Author:

Kyuwon J.

Placenta praeiva ● Implanting lower uterine segment ● overlies /lies to internal cervical os ● Increase in risk of bleeding in case the lower segment thins out or dilation of cervix Classifications ● Use of ultrasound ● Distance from placental edge ~ internal os ○ TVUS ○ Major ● Lower-lying placenta ○ Minor ○ Near os ○ Not completely covering it ■ Edge within ~2cm of os ■ Local definition may vary ● Clinical significance ○ Covers os ⇒ C-sec ○ Low-lying term ⇒ delivery plan on distance ○ Bleeding history ○ Fetal head engagement Epidemiology + Hx ● Midtrimester is point where its commonly detected ○ During anatomy scan ○ Resolves as uterus grows ● Placenta does not just moves ○ Lower uterine segment expansion ■ Placental edge could end up farther from the os Rx ● Previous C-section ○ Increase in risk with number of pas C-sec ● History of placenta praevia ● Multiple gestations ● IVF ○ Assisted reproductive ● Multiparity ● Maternal age ● Smoking ● PAS ○ Increase in risk when praevia and uterine scar exists together Pathophysiology Why does it bleed?? ● Lower uterine segment will form and stretch ● Cervix efface and dilates ● Placental attachment will shear ○ Exposure of maternal vessels ■ Painless ■ Bright red bleeding Clinical ● Painless vaginal bleeding ○ 2nd half of pregnancy ○ Bleeding could be recurrent + variable in volumes ○ Uterus ⇒ typically soft, non-tender ○ Fetal compromise occurs when bleeding is significant ● Placental abruption ○ Painful bleeding ○ Uterine tenderness ○ Hypertonus ■ Can be concealed