Placenta-related things

Question 1

How does betamethasone work?

Answer 1

acts on type 2 pneumocytes to increase surfactant production. Crosses the placenta 1 hour after administration.

Question 2

What is the risk of placenta accreta with a known placenta previa?

Answer 2

For 1st CS: 3%, then 11%, 40%, 61%, and 67%

Question 3

What are signs of accreta on ultrasound?

Answer 3

• presence of placenta previa is biggest risk factor
• multiple vascular lacunae
• loss of the normal hypoechoic zone between the placenta and myometrium
• decreased retroplacental myometrial thickness (less than 1 mm)
• abnormalities of the uterine serosa–bladder interface,
• extension of placenta into myometrium, serosa, or bladder

Question 4

What is definition of placenta accreta?

Answer 4

abnormal trophoblast invasion of part or all of the placenta into the myometrium

increta: placental villi penetrate into the myometrium.

percreta: penetrate through the myometrium to the uterine serosa or adjacent organs.

Question 4

What is the risk of placenta accreta without a previa?

Answer 4

1st CS: 0.03%
2nd CS: 0.2%
3rd: 0.1%
4-5th: 0.8%,
6th: 4.7%

Question 5

What are ultrasound findings of a C-scar pregnancy?

Answer 5

• Low anterior position of gestational sac.
• Placental lacunae
• no myometrium btw placenta and bladder
• Bulging into bladder
• incr vascularity of bladder/placental interface.

1/2000 pregnancies. 7-8 weeks at initial ultrasound. ⅓ of pts are asymptomatic. Most common presenting sx=vaginal bleeding.
NOT more common w/ increasing number of cesareans.

Question 6

How do you counsel patient about CSP?
What are management options

Answer 6

50% risk of MAJOR complications (hemorrhage, hyst, PAS, uterine rupture). placenta accreta spectrum disorders. Discuss option of expectant management vs. termination.

Termination via intra-sac MTX and consultation w/ MIGS for surgical removal and MFM.
- if desires expectant management, deliver via CS at 34-35wks.