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26 Cards in this Set
- Front
- Back
What are the two most common causes of significant bleeding during the third trimester?
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1. Placenta previa
2. Abruptio placenta |
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What is the ddx for 3rd trimester bleeding?
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1. preterm cervical change
2. preterm labor 3. uterine rupture 4. post-coital bleeding 5. bleeding after a pelvic exam 6. vulvar varicose veins, tears of lacs 7. vaginal tears or lacs 8. cervical polyps, cervicitis, carcinoma 9. placenta previa 10. placental abruption 11. vasa previa |
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What must be done before a pelvic exam in the case of 3rd trimester bleeding?
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determine placental position- if there is placenta previa an exam may cause significant bleeding
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cervical ectropion
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reddened, raw looking area of the ectocervix where columnar epithelium has been exposed to vaginal acidity due to eversion of the endocervix-- common and benign
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Regardless of the amount of bleeding, what test should be done for 3rd trimester bleeding?
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type and screen-- may add CBC, coag profile, and crossmatch for 4 units of blood
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What special consideration must be given to Rh D- women?
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need for Rhogam to prevent sensitization. may need to do kleihauer betke test to determine how much rhogam is needed
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placental previa
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placental location close to or over the internal os. Maybe complete, partial, or low lying placenta
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low lying placenta
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placenta extends into the lower uterine segment but does not reach the internal os
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classic presentation of placenta previa
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painless bleeding in the 3rd trimester- about 75% of women with PP will have at least one episode of bleeding.-may start small and get more profound
- bleeding usually occurs around 29-30 weeks - PP occurs in 1 in 200 pregnancies - number of bleeding episodes is unrelated to degree of placenta previa or fetal outcome |
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course of partial or low lying placenta previa
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often resolves by 32-35 weeks of gestation- stretching and thinning of the lower uterine segment moves the placenta away from the os
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What type of US is best for dx of placenta previa?
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TVS
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Risk factors for for placenta previa
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1. placenta previa in a previous pregnancy (4-8% recurrence)
2. prior c/s 3. prior uterine surgery 4. multiparity 5. AMA 6. cocaine use 7. smoking |
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what outcomes are assoc with placenta previa
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- severe fetal CV, CNS, GI and respiratory abn
- inc risk of perinatal morbidity and mortality - inc risk of preterm labor - inc risk of c/s - inc risk of bleeding from lower uterine segment during c/s |
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how long does bleeding from placenta previa usually last?
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1-2 hours
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tx of placenta previa bleeding
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IV fluids, bed rest, and steroids to promote fetal lung maturity if bleeding is not heavy enough to merit immediate delivery (from 24-32 weeks)
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When to deliver in placenta previa
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1. severe bleeding, mom is unstable
2. if patient stable--> amniocentesis to determine fetal lung maturity-- if mature may deliver at 36-37 weeks gestation, if NOT mature-- wait until 37-38 weeks gestation |
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1. placenta accreta
2. placenta increta 3. placenta pancreta |
1. acreta- placental tissue extends into SUPERFICIAL layer of myometrium
2. increta- placental tissue extends deeped into myometrium, but not completely through 3. PANcreta- placental tissue extends completely through the myometrium to the serosa and sometimes into adjacent organs like the bladder |
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1. incidence of placenta accreta?
2. risk factors? 3. potential complications? |
1. 1 in 2500
2. previous c/s 3. inc risk of need for hysterectomy following c/s--> inc risk for maternal and perinatal morbidity and mortality |
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placental abruption
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abnormal premature separation of an otherwise normally implanted placenta
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marginal placental abruption
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separation of the placenta from the uterine wall that is limited to the edge of the placenta
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incidence of significant placental abruption requiring delivery?
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1% of births
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how does placental abruption occur?
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bleeding from the decidua basalis causes separation of the placenta and further bleeding
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classic presentation of placental abruption
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vaginal bleeding and abdominal pain -- if small/partial may only have vaginal bleeding
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concealed abruption/hemorrhage
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blood is trapped behind the placenta and unable to exit-- so no vaginal bleeding
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risk factors for placental abruption
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1. chronic hypertension
2. preeclampsia 3. multiple gestation 4. smoking 5. cocaine 6. AMA 7. multiparity 8. chorioamnionitis 9. trauma 10. h/o placental abruption (inc risk by 15-20-fold) |
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what might an elevated maternal serum aFP in the second trimester indicate?
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10-fold inc risk of placental abruption- because the extra aFP in maternal circulation may be due to AFP entering from uterine placental interface
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