Anemia in pregnancy Flashcards
(29 cards)
Lab values of anemia in pregnancy
1st trimester: <11.0 g/dl
2nd trimester: <10.5 g/dl
3rd trimester: <10.0 g/dl
Physiology changes in pregnancy
Total intravascular volume increases by 50%
Total RBC mass expands by 25%
-> Greater increase in blood volume than increase of RBC mass causes haemodilution (esp in 3rd trimester)
-> Physiological anemia
Total daily iron absorption from gut increases to 20%
Classifications of anemia in pregnancy
- Iron deficiency**
- Megaloblastic
- vit B12 def
- folate def - Hemolytic anemia
a) congenital
- thalessemia**
- sickle cell anemia
- hereditary spherocytosis
b) acquired
- infection
- drugs
- autoimmune - Refractory anemia or Anemia of jolly
Mild bone marrow suppression occurring only during pregnancy, reverts to normal after pregnancy
Causes of anemia in pregnancy
- Decrease intake/absorption
- Poor diet: Lack of iron, folate, vit B12
- Vomiting
- Drugs decreasing absorption of iron
- GI disease/surgery (eg. peptic ulcer disease) - Decreased production
- Renal failure
- Chronic infection
- Bone marrow disorder/suppression - Increased destruction
- Hemolytic anemia:
Thalessemia
Sickle cell anemia
MAHA (DIC, TTP, Eclampsia)
AIHA
G6PD - Blood loss
- Injuries/trauma
- Menorrhagia
- Antepartum/postpartum haemorrhage
- BGIT - Increased demand:
- Multiple pregnancy, repeated pregnancy
Clinical presentations of anemia in pregnancy
Pallor
SoBoE
Palpitations
Giddiness
Fatigue/weakness/poor concentration
Chest pain
Irritability
Hair loss (Fe def)
Tongue discomfort/Disturbance of
taste
Pruritus
Ankle edema
Any bleeding sources? GIT, menstrual
Complications of anemia in pregnancy
Mother
- Mortality!
- Peripartum blood loss
- Increased susceptibility to infection
- Post-partum depression
Fetus
- Preterm delivery
- Low birth weight
- Perinatal mortality
- Reduce brain maturity
What to look out for in FBC in anemia in pregnancy?
=DONE AT BOOKING and at 28 WEEKS=
1. Hb Level?
2. Microcytic vs normocytic vs macrocytic?
3. RDW and retic count
What is the most common type of anemia in pregnancy?
Iron deficiency anemia
What test to confirm iron def anemia?
Iron panel with ferritin
Why is there increased iron requirement in pregnancy?
Increased red cell mass
Increase in muscle mass (particularly uterine
muscle)
Demands of fetus and placenta
Risk factors of IDA in pregnant woman
- Ethnicity (African)
- Teenage pregnancy
- Low socioeconomic class
- Poor absorption
- Heavy menses
- Short interpregnancy interval
- Multiparity
- Postpartum hemorrhage
Management options for Iron Def Anemia
- Lifestyle changes – Eat more leafy greens, beans, red meat, seafoods etc
- Oral iron supplementations
- Parenteral iron
- Blood transfusion
Oral iron supplementations
First line
- Hb > 6.5 before 36 weeks
- Max daily dose 200g to prevent GI upset
- Taken at night or 1h before food
- Fruit juice containing ascorbic acid increases absorption
- Avoid milk, caffeine, tea
- Hb should increase within 2 weeks of PO iron
Side effects of oral iron supplementation
GI S/E
- constipation, diarrhoea, N/V, abdo pain, dark stools
Indication for parenteral iron
- Intolerance to oral iron
- Malabsorption
- Anaemia diagnosed AFTER 36 weeks
*near term, need to replace quickly + compliance issue - Hb <6.5 g/dL
CONTRAINDICATED in 1st trimester
Use of parenteral iron is contraindicated in
First trimester
Side effect of parenteral iron
Headache, N/V, diarrhoea skin discoloration, anaphylaxis
Indication for blood transfusion
- Hypovolemia from blood loss (antepartum haemorrhage)
- Haemolytic crisis
- Hb <6g/dL (abnormal fetal
oxygenation, fetal distress/death)
Thalassemia in pregnancy
Autosomal recessive condition
Genetic defect causes partial or complete suppression of synthesis in either alpha or beta globulin chain, resulting in reduced haemoglobin production in red blood cells
Types of alpha thalassemia
Alpha thal:
HbA genes x4 on chromosome 16 codes for 2 alpha chains
- Defect in 1 gene: Alpha thal minima: asymptomatic, not anemic
- Defect in 2 genes: Alpha thal minor: MILD anemia
- Defect in 3 genes: Haemoglobin H disease (appears healthy at birth then develops haemolytic anemia): MODERATE-SEVERE anemia
- Defect in 4 genes: Hydrops fetalis with Hb Bart’s (4 gamma): INCOMPATIBLE with extra-uterine life
Types of beta thalassemia
Beta thal:
HBb/HbE/HbF genes x2 on chromosome 11 codes for 2 beta chains
- Defect in 1 gene: Beta thal minor: asymptomatic, mild anemia
- Defect in 2 genes: Beta thal major: does not reach childbearing age
Investigations to do for microcytic anemia (thal)
FBC
- Microcytic, hypochromic anemia
- Mentzer’s index < 13
Iron panel TRO Fe def
- Fe, Ferritin, transferrin, TIBC (normal in thal)
PBF
- Target cells (thal)
- HbH inclusion bodies (alpha thal)
Hb electrophoresis**
- Diagnostic for beta thal
- Screening for alpha thal (single gene deletion may be missed out)
Genotyping for alpha thal
Mother is thalassemia carrier/ has thalassemia, what investigation should be done next?
Screen father
If father is found to be a carrier, what should be done?
Genetic counselling + prenatal diagnosis
