Transcript
Iron deficiency anemia:Shall we address it once & for all?
SGH O&G Update7th May 2016
Dr Chai Ming Cheng
Introduction
Anemia in Pregnancy= NOT a diagnosis
IDA=Problem
How common is the problem? (Epidemiology) Why is it a problem? (Pathophysiology)
How to recognize? (Diagnosis)
What can we do about it? (Management)
DefinitionWHO & CDC : Haemoglobin <11.0g/dL + Ferritin <12ug/L
British Committee of Standards in Hematology (BCSH) : 1st trimester <11g/dL : 2nd& 3rd trimester <10.5g/dL : Post partum < 10g/dL
EpidemiologyAnemia – most common medical disorder in pregnancy worldwide
1 in 3 pregnant mothers in Malaysia are anemic95% of them have iron deficiency anemia
Pathophysiology
Pathophysiology
Nadir in Hb occurs around 28-36 wks
Milman N 2008
Implications
IDA: Why is it a problem
IDA: Why is it a problem?Intrapartum: Severe iron deficiency
Poor maternal Hb reserve
Predisposes to atony: Depleted myoglobin impairs uterine contraction
Screening & Diagnosis
Screening for IDAHb to be taken at • Booking• 20-24wks • 36wks
Microcytic hypochromic Ferritin/TIBC?/Serum Iron Sarawak Guidelines Prevention & Management
of Anemia in Pregnancy
Serum Ferritin < 12-15ug/L
: Sensitivity 90%, Specificity 85% : Glycoprotein; Acute phase reactant : 1st test to be abnormal when iron stores reduced : Not affected by recent iron ingestion
BCSH 2011
Management
Absorption - only 10% to 15%
Haem iron more readily absorbed
Dietary advice?
Iron supplementation
• Prophylaxis : 30-100mg/day elemental iron
• Therapeutic: ≥180mg/day elemental iron (100-200mg/day)
Should Iron supplementation be started in ALL pregnant women?
Harms of routine Iron supplementation
• ?Observational studies shown increaserisk of LBW, perinatal death, pretermHb>13.2 @<20wks
• ?Oxidative stress due to free radical formation (intestinal mucosa/placenta)
Intermittent supplementation in non-anemic pregnant women
Rationale = Intestinal cells have limitediron absorption capacity and turn over every 5-6 days
Intermittent supplementation exposes iron to only new intestinal cells,in theory improving absorption
Fewer GI side effectsor Hb >13g/dL
Intermittent vs Daily
No difference in maternal anemia/ Preterm/ LBW
Types of Oral Iron
Iberet
Elemental Iron
Products Elemental IronIberet-Folic 500 105mg Obimin 30mgFerrous Fumarate 200mg
60mg
Iron dextran (IM or IV) 50mg per mlIron sucrose (IV) 20mg per ml
Elemental Iron
Products Elemental IronFerrous Fumarate 200mg
60mg (33%)
Ferrous Sulphate200mg
65mg (32%)
Ferrous Gluconate 60mg (12%)
Follow-up
1st line "Investigation"
Treat with oral iron ≥180 mg/dayExpected increment of 1g/2weeks
Clues:Low MCV/MCH currently BUTNormal baseline Hb & MCV/MCH esp booking bloods in 1st trimester
If not respondingCompliance Dose
Inhibitors
Differentials
Where did the Iron go?
Compliance
Tolerability and GI side effects10-20%
Wrong dose
Inhibitors
Inhibitor of absorption• Phytates (Cereals)• Calcium• Tannins (Tea)
To take between meals/bedtime Up to 40% reduction of absorption if taken with meals
USPSTF 2015
Enhancer of absorption
• Ascorbic acid• Fermentation (Reduces phytate content)• Ferrous iron• Gastric acidity
Loss of Iron
Hookworm infestationGI losses
Reconsider differential
PBFStool Ova and CystHb electrophoresis
Mentzer IndexIDA vs Thalassemia
>13
RBC (106 /mcL)
MCV (fL)
RBC (106 /mcL) =
MCV (fL)
<13
Special groupsThalassemia-Folate 3/12 prepregnancy-Iron if Ferritin< 30ug/L
Renal impairment-Recombinant human erythropoietin
When to refer to tertiary hospital?
• Symptomatic patients• Moderate anemia & failure to response
to oral iron• Severe anemia after 24 weeks
Indication for parenteral
• Malabsorption• Moderate anemia with non-compliance• Severe anemia 24-36weeks
Parenteral iron
•1) Dextran (IM/IV)•2) Sucrose (IV)- less side effects
•Need test dose (0.5mls, wait for 1 hour)•Risk of anaphylaxis (1%)•Increase in 0.8-1.5g/dl/week
•RCT – postpartum – not any superior then oral
Indications for antenatal transfusion
• Patients who are symptomatic• Hb<6g/dL• Hb<8g/dL @>36wks• Placenta Praevia Major Hb<10g/dL• Moderate-Severe anemia in patients
with cardiac/severe respiratory ds• Intolerant oral/Parenteral Iron
IDA: Intrapartum management • Transfuse and transfer to tertiary
hospital if Hb<8g/dL
• Crossmatch 2 pints if Hb 8-10g/dL and transfer to specialist hospital
• 2 large branulas in labour
• Active management of third stage
• Delayed cord clamping
Postpartum
Hb < 10g/dL
• Treatment dose for 3/12• 2wks to raise Hb BUT 3/12 to replenish
iron stores
www.sgh-og.com
References1 Haniff J et. al. Anemia in pregnancy in Malaysia: a cross-sectional survey.
Asia Pac J Clin Nutr 2007;16 (3):527-5362 Nils Milman. Prepartum anaemia: prevention and treatment. Ann Hematol
(2008) 87:949–959. 3. Nils Milman. Iron and pregnancy—a delicate balance. Ann Hematol (2006) 85: 559–5654. Routine Iron Supplementation and Screening for Iron Deficiency Anemia in Pregnant Women: A Systematic Review to Update the U.S. Preventive
Services Task Force Recommendation March 20155. UK guidelines on the management of iron deficiency in pregnancy British Committee for Standards in Haematology 2011
Declaration of interest
Sponsor for O&G Update
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