Tuberculosis in Pregnancy - TOG

Question 1

What is the UK national incidence of TB diagnosed in pregnancy (2005-2006)?

Answer 1

4.2/100,000 maternities

Question 2

Which species of mycobacterium are causative of Tb?

Answer 2

Mycobacterium Tuberculosis 99%
Mycobacterium Africanum 0.5%
Mycobacterium Bovis 0.4%

Question 3

What is the effect of pregnancy on the disease progression of TB?

Answer 3

It’s neither detrimental nor beneficial - doesn’t affect/alter disease process.

Question 4

What percentage of pregnant women with TB are asymptomatic?

Answer 4

1/3 to 1/2 (possibly due to latent phase)

Question 5

What pregnancy complications is a women with TB at higher risk of?

Answer 5

PET
Preterm labour 
Acute respiratory failure 
PPH
Difficult labour in woman with TB compared with control subjects.

Question 6

How does congenital TB present?

Answer 6

Very rare. 
Typically presents in 2nd/3rd week of life with - 
hepatosplenomegaly
Respiratory distress
Fever
Low weight gain
Irritability
Poor feeding

Question 7

How is congenital TB diagnosed?

Answer 7

Cantwells diagnostic criteria for congenital TB

• Presence of TB lesions in infant AND
• lesions in he first week of life
• Primary hepatic complex or caseating granulation
• and/or exclusion of possibility of PN transmission by investigating contact.

Question 8

How is TB treated in pregnancy?

Answer 8

First line: isoniazid/rifampicin/ethambutol for 6 months.

In pregnancy - pyrazinamide can be added for the first two months.

Question 9

How should latent TB be treated if diagnosed in pregnancy?

Answer 9

Delay treatment until after delivery due to risk of hepatotoxicity secondary to isonaizide in early post partum period.

Question 10

How long after treatment are women no longer infectious?

Answer 10

By two weeks of treatment with rifampicin and isonaizide.

Question 11

Infant born to a mother who has had less than two weeks of treatment prior to delivery are at risk of TB - how are these babies managed?

Answer 11

Infant should be given:

• prophylactic isoniazide (5mg/kg) + pyridoxine (vit B6) (5-14mg/kg)
• tuberculin test at 6-12 weeks - if negative then give bcg vaccine and stop prophylaxis
• if positive continue isoniazide and pyridoxine for 6months.

Question 12

Women taking isoniazide who are breastfeeding - what additional precaution should they take?

Answer 12

Pyridoxine (vit b6)