Anaemia (weak blood) in pregnancy

Small drop in haemoglobin (Hb) level is usual in pregnancy. Hb should be

• 110g/L or more in women up to 20 weeks pregnant
• 105g/L or more after 20 weeks

Risk factors for low iron stores at start of pregnancy

• Diet low in 'absorbable iron' — significant problem in remote communities
• Grand multiparity (already given birth 3 or more times)
• Adolescent (teenage) pregnancy — iron also needed for mother's own development
• Twin or multiple pregnancy
• Chronic conditions or infections — diabetes, kidney disease, tuberculosis
• Recent history of bleeding
• Previous anaemia
• Less than a year between pregnancies 

Problems for pregnant woman

• Tiredness
• Increased risk of infection during pregnancy, postpartum haemorrhage, severe anaemia after birth due to poor iron reserve
• Very severe anaemia can cause heart failure

Problems for baby

• Low iron stores cause anaemia
• Low birth weight, preterm birth, perinatal mortality
• Long-term effects on child's development

Ask

• Periods before pregnancy — long or heavy
• Iron in diet
• About risk factors 

Check

• Routine antenatal care includes

• A fall in MCV is the earliest sign of iron deficiency

Other causes of anaemia

• If no known iron deficiency anaemia BUT Hb less than 110g/L up to 20 weeks pregnant or less than 105g/L after 20 weeks — consider other causes
• Take blood for CRP, serum B12, folate, TFT, LFT, UEC

Do

• If POC Test Hb less than 80g/L ​— ​urgent medical consult 
• If POC Test Hb less than 110g/L up to 20 weeks pregnant or less than 105g/L after 20 weeks ​— treat as iron deficiency anaemia, start iron replacement
• Medical consult if
• Unclear if iron deficiency or other cause of anaemia
• Hb does not increase as expected (8–10g/L each week) over first 2 weeks of iron replacement
• Hb still less than 100g/L after 4 weeks of oral iron

Do — iron deficiency anaemia

• Talk about access to healthy food — refer to dietitian
• Getting enough iron and folic acid — red meat, fish, eggs, whole grain breads and fortified cereals
• Include fruits and vegetables with meals
• Avoid drinking tea with meals
• Give vitamin C oral — 500mg once a day to improve absorption of dietary iron
• Give iron replacement
• Take blood for FBC 2 weeks after starting treatment and again 2 weeks after that — should see 8–10g/L increase in Hb each week
• If from an area where hookworm is/has been common OR if MCV low and eosinophil count raised — give pyrantel oral — adult 1g once a day for 3 days
• Do not give ivermectin or albendazole in pregnancy

Iron replacement

Do not give iron supplement if Hb and iron studies normal

Oral iron

• Iron–folic acid oral — 1 tablet (more than 60mg elemental iron) once a day
  
• If woman has side effects — give lower dose
• Iron dose in pregnancy multivitamins may be lower than recommended
• Take iron tablets with water or orange juice — not milk
• Best taken on an empty stomach — 1 hour before meal or 3 hours after meals
• If upset stomach a problem — take with food or at night
• To encourage woman to take iron–folic acid tablets regularly, explain
• Why tablets are important
• Normal that faeces can become dark in colour
• Encourage woman to tell you if she has side effects
• Oral iron alone (without folic acid) can make discomforts of pregnancy worse — eg constipation, heart burn, nausea indigestion and diarrhoea
• Tell woman to keep iron medicine away from children — risk of toxicity
• Continue until 6–8 week postnatal check, reassess

Iron IV infusion

• Do not use
• In first trimester — dates must be checked with dating scan before giving
• If signs of infection
• Use if insufficient time for oral supplements before expected birth date — medical consult
• Consider for women who have a Hb less than 105g/L in second and third trimester as oral supplements unlikely bring it up to normal before birth
• Can be used if oral iron doesn’t work or can’t be used — medical consult
• Ferric (iron) carboxymaltose (eg Ferinject) IV infusion can be given in second and third trimester if
• Prescribed by doctor, in consult with obstetrician in second trimester
• Anaphylaxis kit and resuscitation equipment available
• Discuss risk of IV iron — injection site reaction and paravenous (surrounding tissue of vein) leakage causing skin staining
• Can safely be administered by
• Slow IV bolus injection
• IV infusion using a gravity feed giving set
• IV infusion using an IV infusion pump (preferred)
• Do not restart oral iron until at least 5 days after infusion given
• Do not give more than 20mL (1,000mg) in a single dose. Give second dose at least 1 week after first

Do — Hb normal but iron studies show ferritin less than 30microgram/L

• Give oral iron replacement as above
• Check iron studies and Hb after 4 weeks

Do — megaloblastic (folate deficiency)  anaemia

Anaemic with high MCV and low red blood cell folate

• Medical consult — before starting treatment
• Give iron-folic acid oral — 1 tablet (up to 100mg elemental iron) once a day

AND folic acid oral — 5mg once a day

• Take blood for FBC at 2 weeks then 4 weeks after starting treatment 

Do — anaemia from other causes

• Anaemia due to vitamin B12 deficiency — can have serious short-term and long-term neurological consequences for baby
• Medical consult — doctor may advise vitamin B12 supplement, usually IM
• Talk with woman about foods rich in vitamin B12 — fortified cereals, seafood, liver, meat, cheese, eggs
• If anaemia due to parasitic disease, genetic causes, kidney disease, any other cause — medical consult

Follow-up

• Check FBC and iron studies results 4 weeks postnatal to ensure iron status has corrected
• Ensure babies born to anaemic mothers also have appropriate follow-up with provision of preventative oral iron supplementation — see Anaemia (weak blood) in children and youth