Case 59: Antenatal care

 

Case 59: Antenatal care

CASE 59: ANTENATAL CARE

History

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 deliveries

at term. Her third child is 18 months old and the delivery was complicated by a postpartum

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).

Examination

Blood pressure is 126/73 mmHg.

INVESTIGATIONS (BLOOD TESTS TAKEN AT 28 WEEKS)

Normal range for

pregnancy

Haemoglobin 7.8 g/dL 11–14 g/dL

Mean cell volume 68 fL 74.4–95.6 fL

White cell count 11.2×109/L 6–16×109/L

Platelets 237×109/L 150–400×109/L

Urinalysis: negative

Blood group: A negative

No atypical antibodies detected

Questions

• 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?100 Cases in Obstetrics and Gynaecology

160

ANSWER 59

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.

! Implications of anaemia in pregnancy

• Baby (possible):

• low birth weight

• neonatal anaemia

• cognitive impairment

• Mother:

• antenatal

− fatigue

− fainting

− dizziness

• peripartum

− increased risk of haemodynamic compromise

• increased likelihood of transfusion

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.

Further investigation

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 diseases

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 mg/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.

Further management

Correction of anaemia

• 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).Case 59: Antenatal care

161

• 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.

Delivery

• 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.

KEY POINTS

• Anaemia (not physiological) must be investigated in pregnancy.

• If untreated, anaemia will worsen during pregnancy and blood loss at delivery may

be catastrophic.

• Women with previous PPH must have active management of the third stage.