Iron Deficiency Anaemia

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