Placenta Disorders

Question 1

Explain in general placenta accreta spectrum

Answer 1

Accreta: onto the myometrium
Increta: into myometrium
Percreta: through myometrium and to the uterine serosa or other organs

Question 2

RF for placenta accreta

Answer 2

• Previous C-section (most common) or uterine surgery or deliveries → scar allows for improper embedding into the wall bc weak point
• Trauma
• Concurrent placenta previa
• ≥ 35Y
• Hx of placenta accreta
• Multifetal gestation
• Placenta previa w/ a hx of c-section

Question 3

whats the patho for placenta accreta?

Answer 3

1. Defect of the endometrial–myometrial interface
2. failure of normal decidualization
3. abnormally deep placental anchoring villi and trophoblast infiltration

Question 4

how is placenta accreta diagnosis?

Answer 4

on u/s

otherwise asymptomatic and cannoy be prevented

Question 5

what does placenta accreta result in during childbirth?

Answer 5

Result: incomplete separation of the placenta after childbirth

Cx: Excessive bleeding, preterm delivery, hysterectomy, surgical injury

Question 6

what other ix should you do for placenta accreta?

Answer 6

CBC, electrolytes, VBG/ABG, coags, group and screen

Question 7

how would you manage a preg pt with placenta accreta?

Answer 7

C-section and hysterectomy (always included in consent discussion)

Can consider uterine sparing procedures (expectant management w/ methotrexate or selective tissue removal) if possible and patient is strongly interested, but pt should be counselled on risks

Question 8

define placenta previa

Answer 8

Placenta implants totally or partially in the lower segment of the uterus

Complete previa: internal os completely covered

Partial previa: portion of internal os covered

Marginal previa: edge of placenta extends to the edge of the cervical os

Question 9

RF for placenta previa

Answer 9

• Previous C-section, abortion, uterine surgery
• Smoking
• Multifetal gestation
• Increasing parity (more preg)
• ♀ age
• Hx of placenta previa

Question 10

patho for placenta previa

Answer 10

Prior uterine scars → environment rich in oxygen and collagen → good environment for trophoblast adherence → placenta previa

Question 11

what s/s and physical exam results could you expect from placenta previa?

Answer 11

Painless vaginal bleeding in 2nd or 3rd trimester

Question 12

what ix and physical exams would you do for placenta previa?

Answer 12

Transabdominal/vaginal U/S to assess location of placenta

Speculum exam: may visualize placenta if cervix is dilated

Do NOT complete a digital exam to avoid hemorrhage

CBC, INR/PTT, type and screen

Question 13

how would you manage/tx a placenta previa pt?

Answer 13

most resolve by the time they are due

pt education: no sex and high pelvic load bearing activities

schedule an elective c-section at 36-37wks
give IV magnesium sulfate and corticosteroids to help with lung maturity and neuroprotection

Question 14

define vasa previa

Answer 14

Unprotected fetal vessels passing over the cervical os

Question 15

what are some etiologies/RF for vasa previa?

Answer 15

Velamentous umbilical cord insertion (not in the middle)

Bilobed placenta

Placenta previa

Multiple gestations
Hx of vasa previa

Question 16

what s/s are associated vasa previa?

Answer 16

Asymptomatic

If rupture of cord - Painless vaginal bleeding, fetal distress

Question 17

how do you evaluate vasa previa?

Answer 17

Transabdominal/vaginal U/S to assess location of placenta and umbilical insertion into placenta

Question 18

how do you treat or manage vasa previa?

Answer 18

• Admission to hospital at 32W for close monitoring
• C-section at 35/36 weeks but if bleeding, URGENT because baby can bleed out within minutes
• IV mag sulfate and corticosteroids
• pt education: no sex and high pelvic load bearing activities

Question 19

define placental abruption

Answer 19

placenta partly or completely separates from the inner wall of the uterus >20wks and before delivery

Question 20

RF for placental abruption

Answer 20

Hx of abruption
Abdo trauma
Cocaine use
Chronic HTN
Preeclampsia
Smoking
Multiple gestation

Question 21

what are s/s placental abruption?

Answer 21

painful vaginal bleeding + abdo/back pain
Contractions - threatened preterm labour
Shock s/s

Fetal s/s
- Destress
- bradycardia

Question 22

ix for placental abruption

Answer 22

Clinically diagnosis + blood-stained amniotic fluid

Electronic fetal monitoring

CBC, INR/PTT, type and screen

Question 23

tx for placental abruption

Answer 23

admit
transfuse
deliver baby
IV mag sulfate and steroids if baby premature