Obgyn Third Trimester Bleeding

Front 1

What are the two most common causes of significant bleeding during the third trimester?

Back 1

1. Placenta previa
2. Abruptio placenta

Front 2

What is the ddx for 3rd trimester bleeding?

Back 2

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

Front 3

What must be done before a pelvic exam in the case of 3rd trimester bleeding?

Back 3

determine placental position- if there is placenta previa an exam may cause significant bleeding

Front 4

cervical ectropion

Back 4

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

Front 5

Regardless of the amount of bleeding, what test should be done for 3rd trimester bleeding?

Back 5

type and screen-- may add CBC, coag profile, and crossmatch for 4 units of blood

Front 6

What special consideration must be given to Rh D- women?

Back 6

need for Rhogam to prevent sensitization. may need to do kleihauer betke test to determine how much rhogam is needed

Front 7

placental previa

Back 7

placental location close to or over the internal os. Maybe complete, partial, or low lying placenta

Front 8

low lying placenta

Back 8

placenta extends into the lower uterine segment but does not reach the internal os

Front 9

classic presentation of placenta previa

Back 9

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

Front 10

course of partial or low lying placenta previa

Back 10

often resolves by 32-35 weeks of gestation- stretching and thinning of the lower uterine segment moves the placenta away from the os

Front 11

What type of US is best for dx of placenta previa?

Back 11

TVS

Front 12

Risk factors for for placenta previa

Back 12

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

Front 13

what outcomes are assoc with placenta previa

Back 13

- 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

Front 14

how long does bleeding from placenta previa usually last?

Back 14

1-2 hours

Front 15

tx of placenta previa bleeding

Back 15

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)

Front 16

When to deliver in placenta previa

Back 16

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

Front 17

1. placenta accreta
2. placenta increta
3. placenta pancreta

Back 17

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

Front 18

1. incidence of placenta accreta?
2. risk factors?
3. potential complications?

Back 18

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

Front 19

placental abruption

Back 19

abnormal premature separation of an otherwise normally implanted placenta

Front 20

marginal placental abruption

Back 20

separation of the placenta from the uterine wall that is limited to the edge of the placenta

Front 21

incidence of significant placental abruption requiring delivery?

Back 21

1% of births

Front 22

how does placental abruption occur?

Back 22

bleeding from the decidua basalis causes separation of the placenta and further bleeding

Front 23

classic presentation of placental abruption

Back 23

vaginal bleeding and abdominal pain -- if small/partial may only have vaginal bleeding

Front 24

concealed abruption/hemorrhage

Back 24

blood is trapped behind the placenta and unable to exit-- so no vaginal bleeding

Front 25

risk factors for placental abruption

Back 25

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)

Front 26

what might an elevated maternal serum aFP in the second trimester indicate?

Back 26

10-fold inc risk of placental abruption- because the extra aFP in maternal circulation may be due to AFP entering from uterine placental interface