A woman attends a routine antenatal appointment at 31 weeks’ gestation. She is 26 years old and this is her fourth pregnancy. She has three children, all spontaneous vaginal deliv- eries at term. Her third child is 18 months old and the delivery was complicated by a post- partum haemorrhage (PPH) requiring a 4 unit blood transfusion. This pregnancy has been uncomplicated to date, with normal booking blood tests, normal 11–14-week ultrasound and normal anomaly ultrasound scan.
She feels generally tired and attributes this to caring for her three young children. She reports good fetal movements (more than 10 per day).
Blood pressure is 126/73 mmHg.
· What is the likely diagnosis and what are the implications for the pregnancy?
· What further investigations would you wish to arrange?
· How will you manage this woman for the last trimester of pregnancy?
The haemoglobin is significantly low even for pregnancy, and is associated with a low mean cell volume. This is usually due to iron-deficiency anaemia. Iron deficiency anaemia usually occurs when the woman enters pregnancy with depleted iron stores, although she may not at that stage have low haemoglobin or any signs or symptoms suggestive of anaemia.
At delivery, blood loss is inevitable. This woman has additional risk factors of having her fourth delivery and having a history of PPH. As she is already very anaemic, she may decompensate easily if blood loss occurs, increasing her likelihood of hypovolaemic shock and need for emergency blood transfusion.
Although the likely cause of these indices is iron deficiency, differential diagnoses include a mixed folate and iron deficiency, thalassaemia, chronic bleeding, or anaemia of chronic disease (e.g. renal disease). A full history should therefore be taken to exclude chronic dis- eases and to elicit any family history of thalassaemia.
Iron deficiency should be demonstrated with findings of low mean cell haemoglobin (MCH) and low serum ferritin. Ferritin below 12 μg/L confirms the diagnosis. Serum and red cell folate should also be checked and the woman should be screened for haemoglobinopathies.
If chronic disease is suspected, then further investigations may be indicated such as renal and liver function tests for chronic disease, or gastrointestinal tract endoscopy for causes of chronic bleeding.
· The woman should be prescribed ferrous sulphate 200 mg twice daily, increasing to three times if tolerated. If iron tablets are not tolerated then alternatives include iron suspension or parenteral (intramuscular) iron injections. These are painful and do not increase the serum haemoglobin more than the maximum expected from oral iron (1 g/dL per week).
· In extreme cases, where it is not possible to increase the haemoglobin level by iron supplementation, blood transfusion should be considered.
· An iron-rich diet should be encouraged.
· At delivery, she should be considered at high risk of PPH and have an intravenous cannula inserted in labour, with full blood count and group and save.
· Active management of the third stage is essential (syntometrine, controlled cord traction) and an oxytocin infusion considered if bleeding is excessive or the uterus is suspected to be atonic.
· Following delivery, the woman should continue iron supplementation until iron stores (ferritin) are restored, even if haemoglobin is normal.