8/25- Consultive Hematology (Pregnancy, Age Extremes) Flashcards
What are some changes seen in BV/cell counts/EPO level in pregnancy?
- Blood volume increases by 40-50%
- Plasma volume increase mostly in 2nd trimester
- Red cell mass increases mostly in late 2nd & 3rd TM
- Erythropoietin increases throughout pregnancy & maxes at 150% at delivery
- Platelet count change controversial
- WBC count rises, leukocytosis during labor degree correlated with length of labor
What are some physiologic changes seen in pregnancy designed to prevent women from bleeding out at birth?
PLASMA PROTEINS:
- ESR rises due to anemia and gestational age (result of increased levels of globulins, fibrinogen, so use as a marker of inflammation difficult)
- vWF, fibrinogen, factors VII, VIII, X increase
- Factors II, V, XII stable
- Factors XI, XIII decrease
- Protein C & Antithrombin stable
- Protein S total & free decrease
- Fibrinolysis impaired by PAI I and PAI II
Iron deficiency anemia in pregnancy:
- Epidemiology
- Hb levels
- Requirements in pregnancy
- Risks
- Assessment
Iron def is the commonest cause of anemia in pregnancy worldwide
- Up to 75% African pregnant women
Definition:
- Hb under 11 in 1st and 3rd TMs
- Hb under 10.5 in 2nd TM Require 1 gm of iron during pregnancy
- Exceeds normal Fe storage (300 mg)
- Fetal requirements are always met…
Risks: in first 2 TMs, iron deficiency associated with:
- 2x increased risk of preterm delivery
- 3x increased risk of low birth weight
Assess Fe storage with ferritin and transferrin saturation; Fe supplements as needed
Pica is more common in Fe def pregnant women than other Fe def populations
What is the 2nd most common nutritional deficiency in pregnant women?
Folate deficiency (first is iron)
- Rare in the US
What are folate requirements in pregnancy?
When does anemia typically occur?
What complications may be seen?
- Doubled requirements of folate in pregnancy: 400-800 ug/d
- Anemia usually occurs in 3rd TM and responds in 1-3 days
- Severe pancyotpenia and HELLP-like states have been reported
What happens to B12 levels in pregnancy?
Levels?
Measurement method?
- B12 deficiency is rare in pregnancy, because it’s hard to get pregnant if B12 is deficient
- B12 levels fall during pregnancy due to shift from serum to tissue stores (should not drop below 180 pmol/L)
- MMA levels should be normal if not B12 deficient
What is a common bleeding disorder in pregnancy?
DIC
- Most often from: placental abruption, retained dead fetus, amniotic fluid embolism (AFE)
—-DIC in abruption depends on degree of abruption (delivery and correction of maternal coag are key)
—-DIC due to fetal death may not be detectable for 3-4 wks after fetal demise
—-DIC in AFE results from procoagulant properties of vernix, fetal squamous cells in circulation followed by a fibrinolytic response
- Clinically you will see oozing at IV sites, hematuria, hemoptysis, excessive uterine bleeding…
What does AFE (amniotic fluid embolism) look like?
- Heralded by vascular collapse
- Dyspnea
- Arrhythmias
- Then DIC
- AFE mortality decreased the last few decades (now 30%)
What does Von Willebrand Disease look like in pregnancy?
- Manifestations
- Clotting factor levels/changes
- Treatment/monitoring
- Menorrhagia and post partum hemorrhage are common manifestations
- In types I and II, factor VIIIc and vWF rise in pregnancy, especially 3rd TM (Factor concentrates often unnecessary at delivery)
- Levels fall rapidly after delivery (high risk of hemorrhage)
- Type I pts: monitor VIIIc levels late pregnancy and 1-2 wks post partum
- Bleeding risk minimal if levels > 40 u/dL
What is seen in type 2B vWD in pregnancy? Treatment?
- Platelets may fall significantly in late pregnancy
- May need platelets or plasma derived vWF containing concentrates if they bleed Use of dDAVP is controversial due to risk of placental vasoconstriction and maternal hyponatremia
What treatment for type 3 vWD in pregnancy?
- Need infusion of vWF concentrate at delivery (40-80 IU/KG)
- Then 20-40 IU/kg daily for a week, then taper over a few weeks Use of dDAVP is controversial due to risk of placental vasoconstriction and maternal hyponatremia
What are the nuances for Hemophilia carriers in pregnancy?
- Ideally carriers identified before delivery
- Baseline factor levels measured at 1st visit & 3rd TM
- Remember: FIX (9) levels do not rise in pregnancy
- At a minimum the sex of the fetus should be known before delivery
- C/S not routinely necessary
- Factor VIII or IX level of 40 IU/dl safe for vaginal delivery
To protect potentially affected fetus (50% male offspring of female carrier)
- No vacuum extraction, no forceps
- No IM injections of newborn until status known
- Testing should be done on cord blood (no blood draws)
Mother’s factor level should be followed for several days
What may cause thrombocytopenia in pregnancy?
Gestational and Immune
- Gestational: late and asymptomatic (late b/c of increased plasma volume; dilutional)
- Immunologic: early and more severe
What is the diagnosis for thrombocytopenia in pregnancy?
Same as non pregnant
- Platelet count cutoff between the two = 70,000
When to treat thrombocytopenia in pregnancy?
Treatment methods?
What is the cutoff platelet level for vaginal delivery/C-section?
Treat when?
- Platelets < 10K require treatment
- Platelets >30-50K without bleeding: no treatment
- Platelets 10-30K late in pregnancy or bleeding: treat
- Maternal platelet counts >50,000 safe for vaginal delivery and C/S (but may not be approved for epidural)
Treatment:
- IVIg & steroids are safe, but may have no effect on the fetus
- Splenectomy, if necessary, best in 2nd TM
- Less that 5% of babies born to mothers with ITP will have platelet counts less than 20K
- No clear recommendations on mode of delivery
- Newborns should be monitored for 5-7 days
What is HELLP?
Hemolysis Elevated, Liver Enzymes, Low Platelets
- Clotting a bigger issue than bleeding
- Can cause seizures in pregnant women
- Hematologic manifestations usually resolve with delivery
- Steroids do not help
- If symptoms persist beyond postpartum day 3 – consider TTP and start plasma exchange
