Tuberculosis diagnosed during pregnancy: A prospective study from London

Background - A study was undertaken to characterise the presentation of tuberculosis in pregnancy and the difficulties in diagnosis in an area of the UK with a high incidence of tuberculosis. Methods - A prospective case series was investigated at Northwick Park Hospital, a university affiliated district general hospital in Brent and Harrow health authority in north-west London which incorporates a regional infectious diseases unit. Patients diagnosed with tuberculosis over the study period were included if the onset of symptoms occurred during pregnancy. Results - Thirteen patients were diagnosed during a 30 month period from December 1995 to May 1998 during which 9069 mothers were delivered, a prevalence of 143.3/100,000 deliveries. Symptoms began at a median of 22 weeks gestation (range 9-40 weeks). All patients were recent immigrants of Indian subcontinent or Somali origin and their median duration of residence in the UK was 31 months (range 1-72). Prevalence broken down for racial origin of mothers was 466.3/100,000 for mothers of black African origin and 239.1/100,000 for mothers of Indian origin. Nine of the 13 patients had extrapulmonary tuberculosis. Four patients with widely disseminated disease had a negative Mantoux response and five with localised disease had a strongly positive Mantoux response. HIV co-infection was absent. The median delay between the onset of symptoms and diagnosis was seven weeks (range 2-30). The response to standard treatment was excellent and all patients were cured. Conclusions - Tuberculosis occurring in pregnancy is common in recent immigrants. Diagnosis during pregnancy is delayed because the disease is frequently extrapulmonary with few symptoms.