Anaemia in Pregnancy-hm

Dr Nik Ahmad Nik AbdullahJabatan O&G

Hospital Kota Bharu

OUTLINE Introduction Physiological changes during

pregnancy Nutritional requirements in pregnancy Causes of anemia in pregnancy Symptoms and Signs of anemia Approach to anemia in pregnancy Effect of anemia on pregnancy Management

INTRODUCTION Definition:

a condition of low circulating haemoglobin (Hb) in which the Hb concentration has fallen below a threshold lying at two standard deviation below the median of a healthy population at the same age, sex and stage of pregnancy

However, this is only a statistical definition & not easily understandable & practical

INTRODUCTION WHO Definition

A pregnant mother is considered to be anemic if her Hb level is less than 11g/dl (7.45 mmol/l) & Hct < 0.33

CDC definition : Hb conc < 10.5 d/dL during second

trimester

INTRODUCTION However, many studies in tropical or

developing countries use 10 g/dl as the threshold which defines anemia

(Tee et al, 1984).

INTRODUCTION It is further classified as:

Mild: 10 - 10.9 grams/dl

Moderate: 7 - 10 grams/dl

Severe: 4 - 6.9 grams/dl

Very severe: less than 4grams/dl

WHO Calcification

EPIDEMIOLOGY Overall : 40% of world population

35% for non-pregnant women

51% for pregnant women

3-4x higher in non-industrialised countries Affect 18% in industrialized countries Affect between 35-75% in non-industrialised

countries (average : 56%)

EPIDEMIOLOGY Prevalence ↑ in central-asia

Nearly ½ of the global total anemic women

from Indian sub-continent (in India

alone ~ 88%)

EPIDEMIOLOGYFactors affecting anaemia in pregnancy among rural mothers in Kelantan

Mal J Nutr 3:83-90, 1997

Physiological changes during pregnanacy

 Amount of iron (mg)

 Iron costs        Foetal iron  270      Umbilical cord and placental iron  90    

Maternal blood loss     150  Obligatory losses       230  Expansion of maternal red cell mass     450   Total     1190

 Nett costs       Contraction of maternal red cell mass postpartum    Nett total (b)    

 Total requirement (c)      1040

Adapted from AMA (1968)

Physiologic anemia of pregnancy

Plasma volume increases 50-70 % Beginning by the 6th wk

RBC mass increases 20-35 % Beginning by the 12th wk

Disproportionate increase in plasma volume over RBC volume----Hemodilution

Despite erythrocyte production there is a physiologic fall in the hemoglobin and hematocrit readings

Physiological changes during pregnanacy This iron requirement is distributed

unequally over the 40 weeks of a normal pregnancy.

first 20 weeks of pregnancy are about the same as for a non-pregnant woman.

The expansion in maternal red cell mass occurs maximally between weeks 20 and 25 of gestation, after which the daily iron requirements to maintain this mass remain constant at about 3-4 mg.

Physiological changes during pregnanacy

However, the total iron requirements continue to increase after week 25 up to week 36 due to the needs

of the placenta and the foetus.

The total iron needs near the end of the second and third trimesters are about 3.5 mg/day and 7 mg/day, respectively

(Bothwell, 1995).

Physiological changes during pregnanacy

Physiological changes during pregnanacy As pregnancy continues,

Serum iron ↓

Serum total iron binding capacity (TIBC) ↑ Both changes are due to the increased plasma vol

Plasma & tissue ferritin ↓ - whether given haematinics or not

Insensible losses of iron ~ approx 1 mg/day

4 mg/day of iron absorbed daily from diet

If women enters pregnancy with depleted iron stores, the efx of iron deficiency will develop

Causes of anaemia in pregnancy Nutritional anaemiaDeficiency of o irono folic acido vitaminso protein

Chronic blood losso Repeated abortiono Closely space pregnancyo Menorrhagiao Bleeding gums, ulcer or

pileso Worm infestation

Hemolytic anaemia Thalassaemia Drug-induced

Aplastic anaemia Drug-induced Idiopathic

Myeloproliferative disorders

Causes of anaemia in pregnancy Pathological anaemia of pregnancy is mainly due to iron

deficiency (IDA) Over 90% of anemia due to red cell iron deficiency assoc with

depleted iron stores & deficient intake Infection will inhibit iron binding from the stores into Hb.

Folate defiency : Minor component & assoc with poor diet

Vit B12 deficiency : Rarely causes anemia in pregnancy Addisonian pernicious anemia : doesn’t usually occur in the

reproductive years & usually assoc with infertility

Causes of anaemia in pregnancy Unless the dietary intake is above

average, the requirement is unlikely to be met

Blood loss

NutritionPhysiological

changes during

pregnanacy

FACTORS AFFECTING THE IRON STATUS IN A PREGNANT WOMAN

Absorption. Dietary Habits. Defective in Iron Absorption Loss

FACTORS AFFECTING THE IRON STATUS IN A PREGNANT WOMAN Iron absorption :

Dietary iron (haem & non-haem) Haem iron contained food : animal blood, flesh & viscera

Absorption in normal women : 15-30% but ↑ in IDA up to 50% Non-haem iron contained food : cereal, seeds, vege, milk

Enhancers of absorption Haem iron, proteins, meat, ascorbic acid, fermentation,

ferrous iron, gastric acidity, alcohol, low iron stores, increased erythropoietic activity

Inhibitors of iron absorption Phytates, calcium, tannins, tea & coffee, herbal drinks,

fortified iron supplements

CAUSES OF HIGH PREVALENCE OF IDA Dietary habits

Low bio-availability diet (cereals, roots & tubers)

Assoc with poverty ~ in non-industrialised countries

Assoc with pica ~ ingestion of various substances having no dietary value

Pregnancy complicated with hyperemesis

CAUSES OF HIGH PREVALENCE OF IDA Defective iron absorbtion

Worm infestation, amoebiasis & giardiasis

Other courses of IDA Iron loss

Pathological factors Hookworm & other helminths infestation Haemorrhage from GIT Allergies Occult blood loss

Clinical features

General symptoms and signs of anaemia

Asymptomatic

SYMPTOMS Lethargy Weakness Dyspnoea Palpitation Headache Dizziness

SIGNS Pallor Tachycardia Bounding pulse Cardiomegaly Systolic murmur Angular stomatitis Koilonychia Pica syndrome

Investigation

ANAEMIA IN PREGNANCY :IRON DEFICIENCY - Diagnosis Hb concentration : (late!)

Initially by ↓ iron stores → ↓ serum iron → Hb ↓

Simple non-invasive practical test available

Hb < 10.5 g/dL in 2nd & 3rd trimesters ~ abnormal & require further Ix

ANAEMIA IN PREGNANCY :IRON DEFICIENCY - Diagnosis Red cell indices :

Higher proportion of young large RBC – may mask the efx of iron def on MCV (mean corpuscular vol) in preg + establish anemia This is due to increased drive to erythropoesis

In pregnancy, small physiological increase in red cell size Average : 4 fL but may increase to 20 fL

MCV is a poor indicator – may be normal in iron def

ANAEMIA IN PREGNANCY :IRON DEFICIENCY - Diagnosis

Women with iron def anaemia prior to preg, Will quickly develop florid anaemia in

pregnancy ↓ MCV, ↓ MCH (mean corpuscular Hb) &

↓ MCHC (mean corpuscular Hb concentration)

MCV < 80 fl, MCH < 27 pg ~ in IDA

ANAEMIA IN PREGNANCY :IRON DEFICIENCY - Diagnosis Ferritin

High molecular weight glycoprotein

In healthy adult female (non-pregnant) Circulates at levels : 15 – 300 μg/L Level ≤ 12 μg/L indicates IDA

Important in pregnancy In development of iron def : ↓ serum ferritin – 1st abn lab

test

Hb & ferritin estimations ~ used clinically to categories the pts into normal & abnormal iron stores

ANAEMIA IN PREGNANCY :IRON DEFICIENCY - Diagnosis

Nutritional

Iron in food occurs in two forms, haem iron and non-haem iron.

Approximately 40% of the iron in meat products is haem iron;

60% of the iron in meat and all the iron in plant foods is non-haem iron.

The absorption by the body of the two types of iron differs, with about 2% to 20% of non-haem iron, and about 20% of haem iron, being absorbed.

Food Source Serving Size (oz.) Iron (mg)

Beef, liver 3.0 7.5

Beef, corned 3.0 2.5

Beef, lean ground; 10% fat 3.0 3.9

*Beef, round 3.0 4.6

*Beef, chuck 3.0 3.2

*Beef, flank 3.0 4.3

Chicken, breast w/out bone 3.0 0.9

Chicken, leg w/bone 2.0 0.7

Chicken, liver 3.0 7.3

Chicken, thigh w/ bone 2.3 1.2

Cod, broiled 3.0 0.8

Flounder, baked 3.0 1.2

Pork, lean ham 3.0 1.9

*Pork, loin chop 3.0 3.5

Salmon, pink canned 3.0 0.7

Shrimp, 10 - 2 1/2 inch 1.1 0.5

Tuna, canned in water 3.5 1.0

Turkey, dark meat 3.0 2.0

Turkey, white meat 3.0 1.2

Food Serving Iron content (mg)

   Cashew nuts 2 tbsp 1.0

   Pumpkin seeds 2 tbsp 2.5

   Tahini/Sesame seeds 2 tbsp 1.2

   Sunflower seeds 2 tbsp 1.1

   Molasses 1 tbsp 3.3

   Licorice 50 g 4.4

   Marmite (fortified) 5 g 1.8

   Apricots (dried) 1/4 cup 1.5

   Raisins 1/4 cup 1.1

   Avocado 1/2 1.0

   Prunes 1/4 cup 0.9

   Kelp (cooked) 1/2 cup 42.0

   Nori (cooked) 1/2 cup 20.9

   Parsley (raw) 50 g 4.7

   Potato, with skin (cooked) 1 medium 2.7

   Spinach (cooked) 1/2 cup 1.5

   Broccoli (cooked) 1/2 cup 1.0

   Brussels sprouts (cooked) 1/2 cup 0.9

   Some breakfast cereals    (fortified) 100 g 10 (approx)

   Textured Vegetable Protein (TVP) (cooked) 1/2 cup 2.0

   Barley, whole (cooked) 1/2 cup 1.6

   Wheat germ 2 tbsp 1.2

   Bread, whole wheat 1 slice 0.9

   Rice, brown (cooked) 1/2 cup 0.5

   Tofu 1/2 cup 6.2

   Soybeans (cooked) 1/2 cup 4.4

   Garbanzo beans (cooked) 1/2 cup 3.4

   Lentils (cooked) 1/2 cup 3.2

   Navy beans (cooked) 1/2 cup 2.5

   Pinto beans (cooked) 1/2 cup 2.2

   Lima beans (cooked) 1/2 cup 2.2

   Tempeh (cooked) 1/2 cup 1.8

   Split peas (cooked) 1/2 cup 1.7

   Kidney beans (cooked) 1/2 cup 1.5

   Peas (cooked) 1/2 cup 1.2

   Baked beans (cooked) 1/2 cup 0.

Approach to anemia in

pregnancy

Approach to anemia in

pregnancy

Iron Supplementation in Pregnancy

Safety: Unintentional overdosing, hemochromatosis, GIsymptoms

Compliance: Prescribed Fe supps taken correctlyby 70%, not at all by 10%

Recommendation: Evidence is insufficient to recommend for or againstRoutine iron supplementation during pregnancy.

Iron Supplementation in Pregnancy

• Fe deficiency is common in pregnancy

• Fe supps maintain Hgb levels during pregnancy.

• Percentage of iron absorbed declines as the amount given increases.

• High does increase side effects and decrease compliance.

• Recommendation: Small dose (30mg) after 12 weeks for all pregnant women.

Cochrane Review of 20 Trials- 1999

• “Iron supplementation appears to prevent low haemoglobin at birth or at six weeks post-partum.”

• “Iron supplementation had no detectable effect on any substantial measures of either maternal or fetal outcome.”

Centers for Disease Control. Recommendations to prevent and control

iron deficiency in the United States. MMWR.1998;47:1-36.

• No conclusive evidence for benefit of universal iron supplementation

• Recommend 30 mg/d starting at first prenatal visit because many women have reduced Fe stores with pregnancy

• For Tx of low hct or hbg: 60-120 mg/d– If no response evaluate mean cell volume and serum

ferritin

Yes No Maybe Not enough evidence

IOM - NAS (1990)

Nat'l Perinatal Epi Proj. - Oxford

US Surgeon General (1988)

US preventive Services Task Force (1993)

FASEB (1991)

USPHS Ex. Panel on Prenatal care (1989)

Cochran Review (1999)

CDC (1998)

Recommendations for Routine Iron Supplementation in Pregnancy

Supplement ** For the non-anaemic patient 30 mg of

ferrous iron daily is considered adequate for supplementation.

Treatment 100mg of ferrous

Oral supplements of iron Ferrous Sulfate (200mg), Elemental Iron (65mg),

Supplement Side efx of oral iron administration

Related to the quantity given

Rare side efx with ↓ daily dose to 100 mg & delay introduction till 16 wks gestation

Most common complaint : constipation Other c/o nausea, vomiting, diarrhoea, abd cramping Usually overcome easily with slow release preparation –

but not all iron is released at all & ↑ expanses However, most women can tolerate cheaper preparation

+ folic acid

IM injection of 1000 mg iron : Preparation :

Iron dextran (Imferon) ~ IM / IV Iron sorbitol citrate (Jectofer) ~ IM only

For those whom add iron can’t be given by oral route either by non-compliance & unacceptable side efx

Disadvantage : painful injection & skin staining, + anaphylaxis IM injection ~ less side efx

Iron deficit is calculated as :Elemental Iron need (mg) =

(Normal Hb-Pts’ Hb) x weight (kg) x 2.21 + 100

Mx of IDA With adequate treatment,

An increase of Hb of 0.8g/ dL/ week (1.0 g/ dL/wk in non-pregnant women) – in absence of other abnormalities.

The response is similar with iron given orally or parenterally.

If there is no enough time to achieve reasonable Hb for delivery or symptomatic, transfusion with all its hazards should be considered.

Mx of IDA Blood transfusion

Rarely indicated except severe anaemia regardless of gestation & to replenish blood loss due to APH / PPH

Disadv : transfusion reaction, infectious disease

Mx of IDA

FIRST VISITHigh risk factors

Blood donation - current orrecent historyPrevious iron deficiency

Other risk factors

Poor socio-economicstatus, recentImmigrant Vegetariandiet

 Past history

Post-partumhaemorrhage,multiparity, shortgap betweenPregnanciesHeavyperiods

MCV, Hb, Hct

Criteria:Hb < 10.5gm%Action:

Management asper established protocols for investigation of anaemia in Pregnancy(including serum ferritin assay).

Criteria:Hb=10.5-11.5 gm%And the presence ofone major or two or more of any riskfactors.Action:Specific dietaryadvice: Iron supplementation:at least 30mg/day of ElementalIron Reassess at 28weeks.

Criteria:Hb>11.5 gm% and

no risk factors

present.

Action:

General

Preventative

dietary advice Iron

supplementation is

not required.

SUBSEQUENT EARLY ANTENATAL CARE Assess:

Diet. Presence of nausea, vomiting. Compliance: in those women prescribed iron

supplementation

ANAEMIA IN PREGNANCY :IRON DEFICIENCY – maternal risks In iron def women,

May take > 1 year for Hb to return to pre-preg level.

If iron supplement given, Hb ≈ pre-preg state by 5-7 days after delivery

Blood loss is greater at delivery Due to effect iron def on neuromuscular transmission

& myometrial contraction

ANAEMIA IN PREGNANCY :IRON DEFICIENCY – Fetal risks Children with iron deficiency,

Behavioral abnormalities – related to changes in the concentration of chemical mediators in the brain

Cognitive skills – poor performance which can be improved with iron supplements in some

In utero, Iron def results in low birthweight infants Iron supplements - prevention of adult

hypertension (origin in fetal life due to LBW)

Summary pregnant mother is considered to be anaemic if her

Hb level is less than 11g/dl (7.45 mmol/l) & Hct < 0.33.

Over 90% of anaemia due to red cell iron deficiency assoc with depleted iron stores & deficient intake

Hb & ferritin estimations ~ used clinically to categorise the pts into normal & abnormal iron stores

No conclusive evidence for benefit of universal iron supplementation.