Out of estimated 160 million deliveries occurring annually in the world, approx 6,00,000 women die from the complications of pregnancy & child birth (W.H.O 1996).
Anaemia is responsible for 40-60% of maternal deaths in developing countries. It also increases perinatal mortality and morbidity rates (W.H.O 1997).
Anaemia is a condition of low circulating haemoglobin in which haemoglobin concentration has fallen below the threshold lying at two standard deviations below the median value for a healthy matched population.
W.H.O defines anaemia in pregnancy as haemoglobin concentration of less than 11 g/dl and haematocrit of less than 0.33.
The cut-off point suggested by the United States Centers for disease control is 10.5 gm/dl in the second trimester.
SEVERITY OF ANAEMIA
ICMR describes four grades of anaemia depending upon the haemoglobin levels as shown:
Grades of Anaemia Haemoglobin Value (g/dl) Mild 9-10.9 Moderate 7-9 Severe < 7 Very Severe < 4
Confined to the bone marrow in adults
RBCs are formed through stages of pro-normoblast – normoblast – reticulocytes – mature non-nucleated arithrocyte.
After a life span of 120 days RBCs degenerate and haemoglobin is broken down into haemosiderin and bi-pigment.
For proper erythropoiesis adequate nutrients are needed:
Minerals: Iron, traces of copper, cobalt and zinc.
Vitamins: Folic Acid, Vitamin B12, Vitamin C, Pyridoxine and riboflavin
Proteins: For synthesis of globin moiety.
Hormones: Androgens and thyroxine.
Erythropoietin is a hormone produced by kidneys (90%) and
the liver (10%)
Increased secretion occurs during pregnancy due to placental lactogen and progestrone.
Eryhtropoietin increases red cell volume by stimulating stem cells in the bone marrow.
In addition to common deficiency of folic acid and iron, there is a growing body of evidence to implicate vitamin A in nutritional anaemia.
HAEMATOLOGICAL CHANGES IN PREGNANCY Mean corpuscular haemoglobin = MCH Packed cell volume = PCV Mean corpuscular haemoglobin concentration = MCHC Mean corpuscular volume = MCV Total iron binding capacity = TIBC Characteristic Normal Adult Women 32-34 Weeks Gestation Increased / Decreased Plasma volume (ml) 2600 3850 1250 in Red cell mass (ml) 1400 1640-1800* Increased Haemoglobin (g/dl) 12-14 11-12 Decreased Red Blood Cells (10*6 /mm*3) 4-5 3-4-5 Decreased Packed cell volume 0.36-0.44 0.32-0.36 Decreased Mean corpuscular volume 80-97 70-95 Decreased Mean corpuscular haemoglobin (pg) 27-33 26-31 Decreased Mean corpuscular haemoglobin concentration (%) 32-36 30-35 Decreased Serum Iron (µg/dl) 60-175 60-75 Decreased Total Iron Binding Capacity (µg/100ml) 300-350 350-400 Increased Percentage Saturation (%) 30 15 Decreased Requirements of iron (mg/day) 1.5-2.0 4.0 Increased
PREVALENCE OF ANAEMIA IN PREGNANCY
Overall prevalence – 40% of world’s population
Prevalence of anaemia is 3-4 times higher in developing countries. Average prevalence being 56%.
In industrialized countries approx 18% of women are anaemic during pregnancy.
In India alone the prevalence of anaemia in pregnancy is as high as 88% (W.H.O Global Database 1997).
Haem Iron Pool includes all food containing iron as haem molecules, such as animal flesh and viscera. Its absorption is 15-30%, but it can increase to 50% in iron deficiency state. Its absorption is usually not affected by inhibitors.
IRON DEFICIENCY ANAEMIA (Contd.)
Non-Haem Iron Pool includes cereals, vegetables, milk and eggs. Its absorption can be increased by enhancers and decreased by inhibitors.
Enhancers of absorption: Haem iron, proteins, meat, ascorbic acid, ferrous iron, gastric acidity, alcohol, low iron stores, increased erythropoietic activity.
Inhibitors of iron absorption: Phytates, calcium, tannins, tea & coffee.
CAUSES OF INCREASED PREVALENCE OF I.D.A
Dietary habits: Consumption of low-bio availability diet
Defective iron absorption due to intestinal infections, hook worm infestation, amoebiasis, giardiasis.
Repeated and closely spaced pregnancies and prolonged period of lactation.
IRON REQUIREMENT IN PREGNANCY
Total iron requirement is 1000 mg.
Fetus and placenta -- 300 mg
↑ in red cell mass – 500 mg
Basal loss – 200 mg
Average requirement is 4-6mg/day.
2.5 mg/day in early pregnancy
5.5 mg/day from 20-32 weeks
6-8 mg/day from 32 weeks onwards
PREVENTION OF IRON DEFICIENCY
Prophylaxis of non-pregnant women – 60 mg of elemental iron daily for 3 months.
Iron supplementation during pregnancy.
Routine iron supplementation is debatable in western countries
It has to be given in non-industrialized countries
W.H.O RECOMMENDATION: Universal oral iron supplementation for pregnant women (60 mg of elemental iron and 250 µg of folic acid) for 6 months in pregnancy and additional of 3 months post-partum where the prevalence is more than 40%.
PREVENTION OF IRON DEFICIENCY (Contd.)
MINISTRY OF HEALTH, GOVT. OF INDIA RECOMMENDATION: 100 mg of elemental iron with 500 µg of folic acid in second half of pregnancy for atleast 100 days. 2 injections of iron dextran (250 mg each) given IMI at 4 weeks interval with TT injection.
Treatment of hook worm infestation
Single albendazole (400 mg) or mebendazole (100 mg x BD x 3 days)
Change in defecation habits and avoidance of walking bare footed.
PREVENTION OF IRON DEFICIENCY (Contd.)
Improvement of dietary habits and improving bio availability of food iron
Iron fortification of food.
EFFECTS OF ANAEMIA ON PREGNANCY
ANTE NATAL INTRA NATAL POST NATAL
Poor weight gain Dysfunctional labour Puerperal Sepsis
Preterm labour Haemorrhage & shock Sub-involution
Pre-eclampsia Cardiac failure Embolism
Inter current infections
EFFECTS OF ANAEMIA ON PREGNANCY (Contd.)
Risk of pre-maturity
IUGR, LBW, poor apgar score
Depleted iron store in neonates and anaemia in infancy period
High prevalence of failure to thrive and poor intellectual development.
Cardiovascular morbidity and mortality in adult lives.