Hematologic Complications of Pregnancy

Hematologic Complications of Pregnancy

By:Joseph Breuner, MD

outline

* Anemia

* Thrombophilias

* Thrombocytopenia

Case #1

* Anemia, pro’s and cons of treating

Which patients will benefit from iron treatment?

What hematocrit at 28 wks should generate attention?

* Dilutional or physiologic

* Iron Deficiency Anemia

* Thalassemias

Physiologic Anemia of Pregnancy

* Pregnancy-induced hypervolemia has several important functions:

1. To meet the demands of the enlarged uterus with its greatly hypertrophied vascular system.

2. To protect the mother, and in turn the fetus, against the deleterious effects of impaired venous return in the supine and erect positions.

3. To safeguard the mother against the adverse effects of blood loss associated with parturition.

* Normal hemoglobin by gest age in pregnant women taking iron supp

Iron stores

* The amount of iron absorbed from diet, together with that mobilized from stores, is usually insufficient to meet the maternal demands imposed by pregnancy

Prenatal vitamins

* At DFM contain 27 mg of elemental iron as ferrous fumarate

* Measured this way because different iron salts are absorbed differently

Anemia-who to treat

* CDC: if Hgb is < 11 in 1st or 3rd tri, or <10.5 in 2nd tri * Obtain ferritin, cbc, smear, iron level * If ferritin < 15 mcg/dl, confirms Fe def * If ferritin <30 mcg/dl, 85% PPV and 90%NPV Anemia-who to treat * ACOG-no specific recommendation * Hemoglobinopathy bulletin recommends Anemia-who to treat * Up to date: uses CDC definition 11/10.5 * Follow with dx of cause of anemia: ferritin level, cbc for hemolysis and mcv, electrophoresis if mcv low. Anemia-who to treat * The USPSTF recommends routine screening for iron deficiency anemia in asymptomatic pregnant women. B recommendation. * B. The USPSTF recommends that clinicians provide [the service] to eligible patients. The USPSTF found at least fair evidence that [the service] improves important health outcomes and concludes that benefits outweigh harms. * http://www.aafp.org/afp/20060801/us.html * Cochrane 2006 on routine iron supplementation * The data suggest that daily antenatal iron supplementation: o increases haemoglobin levels in maternal blood both antenatally and postnatally. o increase difficult to quantify due to significant heterogeneity between the studies. o Women who receive daily antenatal iron supplementation are less likely to have iron deficiency and iron-deficiency anaemia at term as defined by current cut-off values * Cochrane 2001, 5 studies * Oral iron treatment in pregnancy was assessed in one small trial (n=125), where it was compared with placebo. * This showed a reduction in the number of women with haemoglobins under 11g/dl (odds ratio (OR) 0.12, 95% confidence interval (CI) 0.06 to 0.24) * greater mean haemoglobin level 11.3g/dl compared to 10.5 g/dl (weighted mean difference 0.80, 95% CI 0.62 to 0.98). * no data on clinically relevant outcomes. * Where’s the outcomes data? o Observational studies published to date in iron-supplemented populations show association between * How to explain this? o Plasma volume expansion is important for fetal growth and well being o High hematocrits likely represent failure of plasma volume expansion o Results persist even when controlled for HTN and preeclampsia My recommendations * Use Hgb 11 in 1st and 3rd and 10.5 in 2nd tri to define anemia * Ferritin, cbc * Ferritin<15=iron deficiency. * Mcv<80=hgb electrophoresis * If neither explains anemia, consider DNA testing for alpha thal * If iron-deficient, treat with iron until * Hgb in normal range (over 11/10.5) * Use ferrous sulfate 325 bid-tid * Or IV iron dextran if not tolerated * If not iron deficient, rule out thalassemias * No need to treat if ferritin ok * Note that real outcome data are lacking * Nutritional history and 3rd world experience dictate practice Thrombophilias * Complex and overlapping sets of recommendations * Key is in history taking * Ask your patient o Have you or a family member had + Blood clot, in the leg or elsewhere? + Stroke? + Temporary blindness or bleeding in the eye? * Understand in terms of clot :relative risk o OCP’s: 4x o personal hx of venous thromboembolism:20x o pregnancy and the puerperium:5x o obesity o surgery o air travel o familial coagulation disorders:1.2-8x * Also understand: Thrombophilias: who to screen * Tests for inherited thrombophilias o Factor V leiden o Prothrombin G20210A o Antithrombin III antigen o Fasting homocystine levels (or MTHFR mutation) o Protein C Ag o Protein S Ag * Inherited tests for antiphospholipid ab syndrome: * Screen inherited and acquired for o Personal or FH<50 of thrombosis o Unexplained IUFD >14 wks

o Preeclampsia <34 wks o Abruption * Screen acquired only for o 1 SAB 10-14 wks o 3 or more SAB’s <10 wks * BID low molecular wt heparin or TID heparin to APTT 1.5x control, and * Postpartum warfarin x 6 wks * Hx of life-threatening thrombosis * Recent thrombosis (?6 mos) * Recurrent thrombosis * On chronic anticoagulation * Personal hx thrombosis and o AT-III deficient o FVL or Prothrombin G20210A homozygote o Heterozygous for FVL and G20210A * Offer prophylactic dosing heparin-5000 units SQ BID or enoxaparin prophy dose * 6 wks postpartum warfarin * For: * Hx of idiopathic thrombosis * Thrombosis due to pregnancy or OCP use * Thrombosis accompanied by any thrombophilia not on previous list * No hx of thrombosis but an underlying thrombophilia and a strong FH (70,000, with two thirds between 130 and 150,000
* Frequency is 5%
* No neonatal thrombocytopenia
o Therefore, considered benign and pregnancy care is unchanged
* Idiopathic thrombocytopenic purpura
o Immune mediated
o Platelet destruction

ITP
* presumptive diagnosis:
o history (eg, lack of ingestion of a drug that can cause thrombocytopenia)
o physical examination
o complete blood count
o peripheral blood smear.
o HIV testing
o Blood pressure, proteinuria, liver transaminases
* Antiplatelet antibody testing not routinely recommended

Preeclampsia/HELLP
* Can present with thrombocytopenia
* Platelet counts not standard screen
* If count below 100,000, evaluate for ITP
o Discuss with consultant
* Evaluate for preeclampsia/hellp
* Follow q 4 wks through pregnancy

References
Hematologic Complications of Pregnancy.ppt