anemia in pregnancy
TRANSCRIPT
Dr Buvanes Chelliah
MD(UKM) MOG(UKM)
Obstetrician & Gynaecologist
Sarawak General Hospital
Malaysian pregnant women : 38.3% (2004)
Disorder by which the body is depleted of RBC to carry adequate oxygen to tissues
Definition of anaemia in pregnancy :
Hb level needs to be checked at booking and again at 28 weeks
1. WHO & Malaysia: Hb < 11.0 g/dl2. CDC
<11.0 g/dl in 1st & 3rd trimester and < 10.5 g/dl in 2nd trimester
↑ plasma volume due to fluid retention (≈ 50%)↑ RBC due to increase in total metabolism (≈ 20-30%)Volume expansion as early as 4th week, peak at 28-34
weeks then plateau until parturition.↑ iron requirement 2-3x
Physiological changes in pregnancy
↑ erythropoietin production erythropoiesis↑In pregnancy, in plasma volume is > than red cell ↑
mass therefore HEMODILUTIONDemand for iron is to meet the needs of the ↑
expanded red cell mass & requirements of developing fetus and placenta
Fetus derives iron from maternal serum by active transport across placenta MAINLY @ last 4 weeks of pregnancy
ANEMIAIMBALANCE OF BOTH PRODUCTION AND LOSS!
Assess both the SEVERITY and CAUSE
IUGR
Low birth weight
Preterm delivery
Cardiac failure
PPH PRETERM LABOUR
WHY IS IT IMPORTANT ?
DELAYED WOUND HEALING
Hb (g/dl)
Mild 9.5 – 10.5
Moderate 8.0-9.4
Severe 6.9 – 7.9
Very severe <6.9
Source : Perinatal care manual (Antenatal care) – Ministry of Health, Malaysia ( 2010)
Decreased Production
Increased Production
Iron Deficiency Anemia Hemolytic Anemia (Thalassemia)
Folate Deficiency Chronic blood loss
Vitamin B12 Deficiency
Bone marrow Failure
Chronic Illness (eg, malignancy)
Commonest anemia in pregnancyPhysiological iron requirements are 3x higher in
pregnancy, with increasing demand as pregnancy advances
Inadequate dietary supplementIneffective absorption Increased iron loss
Dark-green leafy vegetablesIron-fortified cereals wholegrains eg brown rice Beans, peas,soya bean Nuts,peanut butter Meat and fishOatmealsSpinachApricots Prunes Raisins
Tea and coffee Calcium, found in dairy products
such as milk Antacids (medication to help relieve indigestion) Proton pump inhibitors (PPIs), which affect the
production of acid in your stomach Some wholegrain cereals
contained phytic acid
Routine Hb (if all normal)Booking20-24 weeks36 weeks
Generally assumed that a woman who is or becomes anaemic in pregnancy is iron deficient, but the diagnosis should be confirmedFull blood picture (FBP)Iron studies
Serum iron (?)Serum ferritinTotal-iron biding capacity (TIBC)
Hb electrophoresis (if haemoglobinopathy is suspected)UFEME (?)Stool for ova & cyst (?)
Oral supp. of 60-80 mg elemental iron /per dayfrom early pregnancy maintains Hb in the normal range for pregnancy but does not maintain or restore the iron stores (1 tablet of ferous fumarate/day).
WHO: 30-60 mg per day for women with normal iron stores (1 tab of obimin/1 tab of ferous fumarate)
Elemental iron : iron in the supplement available for absorption
Those who are already anaemic/depleted iron store requiring 120-240 mg elemental iron per day ( 2-4 tab of ferous fumarate).
Oral iron-Hb rises from 0.3-1.0 g per week.Up to 10% women-side effects esp GIT (nausea,
vomiting, constipation, abd cramp etc)-dose relatedIf intolerable- change iron preparation or change to
parenteral iron (Imferon). If no significant improvement within 3 wks, diagnostic
re-evaluation is needed
• FeSO4 525mg (105mg elemental iron)
• Folic acid 800mcg• Thiamine (B1) 6mg• Riboflavin (B2) 6mg• Nicotinamide 30mg• Pyridoxine (B6) 5mg• Cyanocobalamin (B12) 25mcg• Calcium pantothenate 10mg• Ascorbic acid (C) 500mg
Complete iron supplementation enriched with folic acid, vitamin C & B complex
Patient needs to take the tablet 3X per day to achieve this dosage,
compliance is an issue
Parenteral iron-rise in Hb concentration is same as with oral iron (up to 1 g per week).
Elemental iron needed(mg)=(Normal Hb – pt’s Hb) x wt(kg) x 2.21 + 1000.
IM iron- a test dose of 50 mg, followed by 100 mg daily or alternate days by deep IM inj on the outer quadrant of buttock
Disadv- pain,abscess,nausea,vomiting, headache,rarely anaphylaxis
IV infusion-careful with reactions such as chest pain,chills,rigor,dyspnoea,anap-hylactic reaction-inj epinephrine,hydro-cort & oxygen should be available.
Other causes? non compliance!On going blood loss?Concomitant folate/B12 deficiencyThalassaemia
WHEN DO WE SCREEN?In patients who have a significant family history of thalassemiaMCH is the most important screening parameter for thalassaemia. A low MCH (< 27) even with a normal haemoglobin levels is an indication to screen for thalasemia.In thalassaemic patients, RBC s are normal or high.Use the Mentzer index as a guide. ( MCV/RBC count < 13 favours thalassemia over iron deficiency.)· This test has a high sensitivity but low specificity.·
Hb <7g/dL transfusion usually requiredSevere anaemia with heart failureHb < 8 gm % at term or in early labour
Use packed cells!Complications may follow
GXM at least 2 units and transfusion require
High risk patient with Hb between 8-10g/dl require at least 2 pint of blood ( GXM) AND transfer to the hospital with specialist if possible
Patient with risk of PPH and anaemic is best delivered in the hospital with specialist
THANK YOU