Placental Pathology Flashcards

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Questions and Answers

What is placenta accreta?

When part of the placenta, or the entire placenta, invades and is inseparable from the uterine wall.

What are the types of placenta accreta and how are they differentiated?

Accreta is the general term for invasion of the trophoblasts onto the myometrium. Increta penetrates into the myometrium, and percreta is invasion through the myometrium and serosa.

What places women at risk of placenta accreta?

Previous C/S scar.

What happens after delivery in a woman with placenta accreta?

The placenta does not separate, and attempts at removal lead to hemorrhage. Signup and view all the answers

What are the new classifications of placenta previa?

True placenta previa covers the internal cervical os, while low lying placenta is within 2cm of the os but does not cover it. Signup and view all the answers

Why is it necessary to monitor placenta previa in the 2nd trimester?

As the uterus grows, 90% of placenta previa early in pregnancy will migrate away from the os. Signup and view all the answers

What are risk factors for placenta previa, modifiable and non-modifiable?

Non-modifiable: Increased parity, AMA >35, Asian women, multiple gestation, male fetus, previous previa, hx C/S. Modifiable: Cigarette smoking, cocaine use, higher elevation, infertility treatment. Signup and view all the answers

What is the classic presentation of placenta previa?

Painless vaginal bleeding in the late 2nd or early 3rd trimester. Signup and view all the answers

What is the classic presentation of abruptio placentae?

Vaginal bleeding with abdominal pain, hypertonus, or board-like abdomen. Signup and view all the answers

Name risk factors for placental abruption.

Prior abruption, HTN of any kind, PPROM, smoking, cocaine, polyhydramnios, fibroids. Signup and view all the answers

What is a concealed abruption and how does it present?

The midsection of the placenta separates from the uterine wall, may only present as cramping, contractions, and uterine tenderness with no bleeding. Signup and view all the answers

What is the usual structure of the cord and placenta when vasa previa is present?

Velamentous cord insertion, no Wharton's jelly, and placenta is bilobed or succenturiate. Signup and view all the answers

What are amniotic bands and how can they impact a pregnancy?

Membrane segments that form strings and can constrict limbs or cause other deformities. Signup and view all the answers

How is placenta accreta managed?

Accurate prenatal diagnosis and management at a center with surgery, OB, IR full team; fetal corticosteroid injections to advance lung maturity; delivery after 34 weeks depending on severity of bleeding. Signup and view all the answers

What should be avoided in a patient with placenta previa?

Intercourse, some physical exercise, digital exams. Signup and view all the answers

When is C/S indicated in women with placenta previa or low lying placenta within 2cm of os?

STAT with non-reassuring FHR and bleeding; expectant management in stable women until scheduled C/S at 36-37 weeks. Signup and view all the answers

Aside from bleeding, what is a concern with vasa previa?

Cord compression leading to fetal hypoxia. Signup and view all the answers

When does the peak occurrence of placental abruption happen?

24-26 weeks. Signup and view all the answers

Study Notes

Placenta Accreta

Definition: Invasion of the placenta into the uterine wall that prevents separation after delivery.
Types:
- Accreta: General term for trophoblast invasion.
- Increta: Invasion into the myometrium.
- Percreta: Invasion through both myometrium and serosa.
Risk Factor: Previous Caesarean section (C/S) scar.
Post-delivery Complications: Failure of placental separation leads to hemorrhage.

Placenta Previa

New Classifications:
- True placenta previa: Covers the internal cervical os.
- Low lying placenta: Within 2 cm of the os but does not cover it.
Monitoring Necessity: 90% of early pregnancy cases migrate away from the os as the uterus grows.
Risk Factors:
- Non-modifiable: Increased parity, advanced maternal age (≥35), Asian ethnicity, multiple gestation, male fetus, history of previa, previous C/S.
- Modifiable: Cigarette smoking, cocaine use, higher elevation, infertility treatment.
Classic Presentation: Painless vaginal bleeding in late second or early third trimester.

Abruptio Placentae

Classic Presentation: Vaginal bleeding accompanied by abdominal pain, hypertonus, or a board-like abdomen.
Risk Factors: Prior abruption, hypertension, preterm premature rupture of membranes (PPROM), smoking (dose-dependent), cocaine use, polyhydramnios, fibroids.
Concealed Abruption: Midsection separation from the uterine wall; may only show as cramping, contractions, and tenderness without bleeding.

Vasa Previa

Typical Structure: Velamentous cord insertion with potential absence of Wharton's jelly; may involve bilobed or succenturiate placenta.
Concerns: Cord compression can lead to fetal hypoxia.

Amniotic Bands

Definition: Membrane segments that form constricting strings.
Impact: Can lead to limb constriction or other deformities.

Management Strategies

Placenta Accreta:
- Ensure accurate prenatal diagnosis and manage at specialized centers equipped for surgery.
- Administer fetal corticosteroid injections to enhance lung maturity.
- Consider delivery after 34 weeks based on bleeding severity.
Placenta Previa:
- Avoid intercourse, certain physical exercises, and digital examinations.
- Indications for C/S:
  - Emergency (STAT) if fetal heart rate (FHR) is non-reassuring with bleeding.
  - Stable conditions may allow expectant management until a scheduled C/S at 36-37 weeks.

Peak Occurrence of Placental Abruption

Typically occurs around 24-26 weeks of gestation.

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Description

Test your knowledge on placental pathology with these flashcards. This quiz covers important concepts like placenta accreta and its different types. Perfect for medical students or professionals studying obstetrics.