Pathology of Placenta Flashcards
What is a spontaneous abortion?
- miscarriage of fetus before 20 weeks gestation (usually 1st trimester).
- presents with vaginal bleedings, cramp-like pain, and passage of fetal tissues.
- occurs in up to 1/4 of pregnancies.
What causes most spontaneous abortions?
- CHROMOSOMAL ANOMALIES (trisomy 16)
- others include hypercoagulable stages (antiphospholipid syndrome, lupus), congenital infection, and exposure to teratogens (especially during first 2 weeks).
What weeks of gestational development tend to cause organ malformation?
- weeks 3-8
** What is PLACENTA PREVIA?
- implantation of the placenta in the lower uterine segment; placenta overlies cervical os (opening).
- think you are getting a “PREVIEW” of the placenta because you can see it.
How does PLACENTA PREVIA present?
- 3rd trimester bleeding and often requires C-section delivery.
** What is PLACENTAL ABRUPTION?
- separation of placenta from the decidua prior to delivery of the fetus.
- presents with 3rd trimester bleeding and fetal insufficiency.
Is Placental Abruption a common cause of still birth?
YES
** What is PLACENTA ACCRETA?
- improper implantation of placenta into the myometrium with little or no intervening decidua.
- presents with difficult delivery of the placenta and postpartum bleeding.
What does Placenta ACCRETA often require?
- hysterectomy.
*** What may be seen in the vessels of the placenta in a mother with preeclampsia?
- Fibrinoid necrosis
What is Sudden Infant Death Syndrome?
- death of healthy infant (1 month to 1 year old) without obvious cause.
- usually expire during sleep
What are the risk factors for sudden infant death syndrome?
- sleeping on stomach
- cigarette smoke
- prematurity
** What is HYDATIDIFORM MOLE?
- abnormal conception characterized by swollen and edematous villi with proliferation of trophoblasts. (cells that surround the villi).
- uterus expands as if normal pregnancy, but BIGGER than normal.
Will b-hCG be higher or lower in HYDATIDIFORM MOLE?
- HIGHER
How does HYDATIDIFORM MOLE present without prenatal care?
- passage of GRAPE-LIKE masses in early 2nd trimester through the vaginal canal.
How is HYDATIDIFORM MOLE diagnosed WITH prenatal care?
- “SNOW-STORM” appearance on US in early 1st trimester.
- fetal heart sounds absent.
How are molar pregnancies classified?
- as COMPLETE or PARTIAL.
* based on genetics, fetal tissue, villous edema, trophoblastic proliferation, and risk for choriocarcinoma.
** How should we think about a COMPLETE molar pregnancy?
- as most things in life, this is COMPLETELY DAD’S fault: 2 sperm fertilizing an empty egg cause COMPLETE mole bc this is COMPLETELY dad’s (PATERNAL) fault and thus 46 chromosomes bc 2 sperm.
- Bc this is COMPLETELY a mole, there is no other fetal tissue (aka fetal tissue absent).
- all villi are edematous/hydropic (i.e. they are COMPLETELY edematous).
- COMPLETE proliferation of trophoblsts all around the hydropic villi.
- B-hCG is higher here bc you have more trophoblastic proliferation.
- complete mole has a greater risk; 2-3% (i.e. COMPLETE risk) for choriocarcinoma.
- may see HYPERthyroidism.
- will not see embryological parts.
** How should we think about a PARTIAL molar pregnancy?
- a normal egg is fertilized by 2 sperm= 69 chromosomes.
- this is PART fetal tissue and PART mole so fetal tissue will be present.
- villi will be PARTIALLY edematous.
- PARTIAL trophoblastic proliferation around hydropic villi.
- PARTIAL risk for choriocarcinoma (i.e. lower risk).
- will often see embryo parts.
How do you treat a molar pregnancy?
- dilation and curettage (D&C)
- subsequent B-hCG monitoring to ensure adequate mole removal and to screen for choriocarcinoma.
** What is CHORIOCARCINOMA?
- tumor of TROPHOBLASTS that arises as a complication of GESTATION (spontaneous abortion, normal pregnancy, or hydatidiform mole) or as a spontaneous GERM cell tumor.
- NO VILLI.
- hCG and KERATIN +
What cells secrete B-hCG?
- syncytiotrophoblasts
** Does the GESTATIONAL pathway or GERM CELL pathway leading to choriocarcinoma respond best to chemotherapy?
- GESTATIONAL pathway (usually after a MOLE)
* germ cell pathway does NOT respond well to chemo.
What are the 2 ways placental infections can occur?
- ASCENDING through birth canal (more common).
2. HEMATOGENOUS route (ransplacental).
What may indicate placental infection?
- cloudy amniotic fluid with purulent exudate.
- may have inflammation of the umbilical vessels.
*** What are the TORCH infections?
- Toxoplasmosis, Trepanema (syphilis), TB
- Rubella
- CMV
- HSV
- Listeria
With what is chronic vilitis associated?
- intrauterine growth retardation.
- stillbirths
- look for inflammation of the placental maternal side.
** What is acute FUNISITIS?
- inflammation of the UMBILICAL CORD.
** What is placental infarct?
- area of VILLOUS NECROSIS due to local obstruction of the maternal uteroplacental circulation.
- Fresh infarct is DARK RED and FIRMER than surrounding tissue.
- high incidence of NEONATAL ASPHYXIA, LOW BIRTH WEIGHT, and INTRAUTERINE DEMISE.
What can cause placental infarct?
- placental abruption (abruptio placentae).
*** What marker will you see in PARTIAL moles that is absent in complete moles?
- p57 (cell cycle inhibitor)
** What is an INVASIVE mole?
- usually a complete mole, that PENETRATES deeply into the MYOMETRIUM, leading to significant hemorrhage.
- contains villi.
