Case 71: Itching in pregnancy

 

Case 71: Itching in pregnancy

CASE 71: ITCHING IN PREGNANCY

History

A 36-year-old woman is complaining of itching. She is currently 34 weeks’ gestation in her

first ongoing pregnancy, having had two previous early miscarriages. The itching started 2

weeks ago and she had been using emollient cream to try and relieve it. Initially it was mainly

over her soles and palms, although it is now more generalized. She is not aware of having

changed her washing powder or soap recently and no one else in her family has been affected.

She has not experienced any abdominal pain although she does have Braxton Hicks contractions. There is no vaginal discharge or bleeding. She has noticed the baby move more than 10

times in the last 12 h.

Examination

She looks well. Her blood pressure is 118/76 mmHg and pulse 82/min.

No rash is visible on the face, trunk, limbs, hands or feet except for a few excoriation marks.

The symphysiofundal height is 34.5 cm and the uterus is soft and non-tender. The fetus is

cephalic with 4/5 palpable abdominally.

INVESTIGATIONS

Normal for

pregnancy

Haemoglobin 10.3 g/dL 11–14 g/dL

Mean cell volume 80 fL 74.4–95.6 fL

Platelets 198×109/L 150–400×109/L

Sodium 132 mmol/L 130–140 mmol/L

Potassium 3.3 mmol/L 3.3–4.1 mmol/L

Urea 2.9 mmol/L 2.4–4.3 mmol/L

Creatinine 68 mmol/L 34–82 mmol/L

Alanine transaminase 31 IU/L 6–32 IU/L

Alkaline phosphatase 120 IU/L 30–300 IU/L

Gamma glutamyl transaminase 12 IU/L 5–43 IU/L

Bilirubin 8 mmol/L 3–14 mmol/L

Bile acid 24 mmol/L 0–14 mmol/L

Urinalysis: nil abnormal detected

Questions

• What is the diagnosis?

• How would you further investigate and manage this woman?

• How will this diagnosis affect the pregnancy?100 Cases in Obstetrics and Gynaecology

194

ANSWER 71

The woman is suffering from obstetric cholestasis (OC). This is a pregnancy-specific condition in which there is intrahepatic reduction of bile excretion from the liver, causing a buildup

of serum bile acids. It usually develops in the third trimester. The effect on the mother is of

itching, which may be very distressing. In more severe cases the liver function or coagulation becomes deranged, and if this occurs then other diagnoses such as HELLP syndrome

(haemolysis, elevated liver enzymes and low platelets – a severe form of pre-eclampsia) or

hepatitis should be considered. An ultrasound should be performed to exclude other causes

of obstruction such as gallstones.

There is no long-term harm to the mother. The effect on the baby however is potentially much

more serious with an association between OC and stillbirth.

Investigations

Liver ultrasound should be performed to exclude other causes of hepatic obstruction. Fetal

ultrasound may be performed for maternal reassurance.

Management

Symptomatic relief is obtained from chlorpheniramine (antihistamine). Ursodeoxycholic

acid can be given to relieve itching in more severe cases, as it reduces serum bile acids.

Vitamin K (needed for clotting factors) should be given orally to the mother to reduce the risk

of fetal or maternal haemorrhage caused by impaired absorption.

Induction of labour at around 37 weeks is indicated to minimise the chance of stillbirth.

Postnatal advice

Maternal liver function returns to normal after delivery, but the mother should be warned

that recurrence may occur in a subsequent pregnancy (50 per cent) or with use of the combined oral contraceptive pill.

KEY POINTS

• Itching in pregnancy may be due to obstetric cholestasis.

• In severe cases maternal liver and coagulation function can become deranged,

but usually the major risk is to the fetus.

• There is a high risk (50 per cent) of recurrence in future pregnancies.