Anaemia in pregnancy

Question 1

Haemodynamic changes in Pregnancy

Answer 1

Red cell mass increases 18-25%
Plasma volume increases 44-55%
Due to haemodilution there is apparent anaemia
Also–> WBC up, platelets down 20-36 weeks, increased factors VII/VIII+X, ESR and fibrinogen

Question 2

Changes in Iron metabolism in pregnancy

Answer 2

Increased demands from fetus – MET by –>
Increased Iron absorption –> dietary issues
Mobilization of iron resources –> dangerous if depleted pre-pregnancy (menorrhagia, short interval from last pregnancy or parasitic infections)

Question 3

Role of Folic Acid in pregnancy

Answer 3

Increased demand for DNA production and growth from the uterus, placenta and fetus –> deficiency linked to neural tube defects
0.5mg daily to 12 wks, 5mg for rest of pregnancy

Question 4

Definition of Anaemia in pregnancy

Answer 4

NICE and WHO agree:
Over 12 weeks –> 110g/L or less
28 to 30 weeks –> 105g/L or less
Postpartum —> <100g/L

Question 5

Risks of Anaemia in pregnancy

Answer 5

Maternal –> tiredness and SOB, increased risk of haemorrhage
Fetal –> increased risk of poor outcomes and complications

Question 6

Types of Anaemia

Answer 6

Microcytic –> Iron deficiency
Macrocytic–> Folate or B12 deficiency
Hereditary –> Sickle cell (trait;SC, homozygous SS) + thalassaemias

Question 7

Screening for anaemia in pregnancy

Answer 7

Hb and Haemoglobinopathy screen at 12 week
28-30 wks recheck haemoglobin
If Hb is low investigate and give iron supplements

Question 8

Iron Deficiency Anaemia

Answer 8

50% of women in world and 20% in first world
Aim for 10g increase/wk–> recheck after 4 wks
Increases haemocrit slightly at all points but mostly in the 3rd trimester
If not anaemic only give in multiple pregnancies

Question 9

Oral Iron

Answer 9

Ferrous sulphate 200mg up to TDS
SEs–> 30% GI upset (vomiting or constipation)
treat by reducing dose or changing formulation (liquid, have with meals etc
Haem-iron and non-haem iron stores in food

Question 10

Other Treatments for IDA

Answer 10

Parental iron –> IM (pain and discolouration) or IV (anaphylaxis)
Transfusions –> infection, transfusion reaction
Consider if high risk (placenta previa)

Question 11

Folate deficiency anaemia

Answer 11

Rarer –> epileptics, alcoholics, haemolytic anaemia or drugs (azathioprine)
Confirm with red cell folate –> treat with folate 5mg daily

Question 12

B12 Deficiency

Answer 12

Rare and usually due to pernicious anaemia which predates pregnancy
Strict vegans
treat with B12 supplementation

Question 13

Hereditary Anaemias

Answer 13

Sickle is most common–> if mother is carrier check partner

Offer CVS/amnio

Question 14

Sickle Cell disease in pregnancy

Answer 14

increased risk of Sickle crises (occur in 35% of pregnancies) –> preinatal mortality up 4-6x due to IGUR, preterm labour & fetal distress
Increased maternal mortality –> PET, VTE, infections, high CS rate

Question 15

Mangement of Sickle cell in pregnancy

Answer 15

Manage crises as if non-pregnant
treat with folate and regular USS to check fetus
Peripartum–> LSCS if indicated, CTG, hydrate mother, analgesia

Question 16

Thrombocytopenia

Answer 16

Occurs in 5-10% of women at term--> 75% gestational, can be immune or DIC, rarely is SLE, HIV, haemolytic uraemic syndrome
If ITP (will predate pregnancy)

Question 17

Management of thrombocytopenia

Answer 17

Gestational is benign–> normal plts at booking
–> treat symptomatically or prophylatically if persistent check autoantibodies, exclude other causes
Can cause bleeding, antiplatelet IgG can cross placenta –>2% will have fetal problem
–> avoid instruments or FBS, check cord blood

Question 18

Rhesus Genes

Answer 18

Rhesus group is c,d & e. Rh+ve must be D positive and can be CDE, CDe, cDE, cDe
cde is negative

Question 19

Rhesus Disease

Answer 19

An Immune-haemolytic anaemia of the fetus
Causes fetal mortality and morbidity
If survives causes prematurity, anaemia and jaudice

Question 20

Other Blood antibodies

Answer 20

There are 100 RBC antigens, 30 can cause fetal haemolytic disease, Anti-D is 98%
Can also be other rhesus antigens (C or E), Kell, Duffy or Kidd

Question 21

Sensitising Events for Rhesus disease

Answer 21

Fetomaternal Haemorrhage
Early pregnancy loss or bleeding
Invasive procedures
Antepartum Haemorrhage
Labour and delivery

Question 22

Anti-D

Answer 22

1st trimester–> all operations (ectopic/ERPC/TOP)
2nd trimester–>miscarriage(threatened),CVS/amino
–> 250iu of anti-D
3rd trimester all Rh-ve women get 500iu of anti-D

Question 23

Kleihauer test

Answer 23

Measures the size of FMH –> uses acid which fetal cells are more tolerant of
500iu of anti-D protects against 4ml of FMH

Question 24

Current rate of sensitization

Answer 24

~1%
Due to incompatible transfusions
Or mismanagement of previous pregnancies–> Anti-D not given or not enough, spontaneous fetomaternal haemorrhage (FMH)

Question 25

Management of sensitised women

Answer 25

If untreated–> 50% of infants will have none to mild anaemia, 25% will have moderate anaemia, 25% will develop hydrops
With Transfusion there is >80% survival
Risks–>Cord tamponade, haemorrhage or miscarriage

Question 26

Neonatal problems related to rhesus disease

Answer 26

Major risk is prematurity
If Anaemic transfuse Rhesus negative blood
Haemolysis of RBCs can lead to jaudice–> treat with phototherapy or exchange transfusions

Question 27

Prevalence of Anaemia in pregnancy

Answer 27

Overall 40% of the world

56% in developing countries and 18% in developed countries

Question 28

Causes of Anaemia in pregnancy

Answer 28

Deficiency - reduced production or increased loss of RBCs

Haemodilution –> plasma volume increases disproportionately

Question 29

Symptoms of anaemia in pregnancy

Answer 29

Most commonly: Tiredness, Lethargy & SOB
Less commonly: headache, tinnitus, altered sense of taste, sore tongue, feeling itchy
Pica (the desire to eat non-food items, paper/clay etc)

Question 30

Maternal risks from anaemia

Answer 30

Poor weight gain, Preterm labour, PE, abruption, Haemorrhage/shock, PPH, sepsis

Question 31

Fetal risks from anaemia

Answer 31

Risk of prematurity, IUGR or low birth weight, anaemia in infancy, Failure to thrive and poor intellectual development

Question 32

Inhibitors and Enhancers of iron absorption

Answer 32

Inhibitors–> phytates, tannins,Ca, tea & coffee

Enhancers –> haem iron, proteins, meat, ascorbic acid, gastric acidity and alcohol

Question 33

Haem iron versus non-haem iron

Answer 33

Haem iron is in the haem molecule so found in meat, while non-haem iron is in eggs and cereal etc