Tuberculosis in pregnancy in the UK
Authors’ Reply

Authors


Sir,

We thank Dr Jana and colleagues1 for their interesting discussion. They comment that it is surprising that only one case of TB in pregnancy was seen in the non immigrant population, given that one-quarter of all cases of TB in the UK occur in individuals born in the UK. These national statistics from the Health Protection Agency include cases occurring in both genders and all age ranges; 55% of cases occur in men and 40% occur in individuals outside of the reproductive age range. Our study suggests that the pattern of TB in pregnancy is different in several ways from that in the population as a whole and therefore, this observation is not unexpected.

We agree that tuberculosis in pregnancy remains a potential danger for mothers and infants and that raising awareness of this is important. Information from the UK Confidential Enquiry into maternal deaths demonstrates that even in developed countries such as the UK, women still die from tuberculosis in pregnancy.2 In the most recent period for which data are available (2003–05), three women died with tuberculosis during pregnancy and in two of these, the disease was extrapulmonary.2Table 1 shows the sites of disease in our series and illustrates the range of potential presenting symptoms and signs.

Table 1.   Sites of disease in women with TB in pregnancy
Site of diseaseNumber of womenExtrapulmonary sites (n)
  1. *Diagnosed at delivery following a hysterectomy to control severe peripartum haemorrhage.

Pulmonary16
Pulmonary and extrapulmonary 3Lymph nodes (1)
Abdomen (1)
Central nervous system (1)
Extrapulmonary13Lymph nodes (7)
Spine (2)
Abdomen (1)
Central nervous system (1)
Pericardium (1)
Uterus (1)*
Unknown 1

In addition to our series,3 two recent UK hospital-based case series suggest that extrapulmonary disease is as common as pulmonary in our population.4,5 It is interesting to speculate on the differences observed between the patterns we observed and the patterns in India. Drs Jana and colleagues1 suggest that it may be because of missed cases of less severe (pulmonary) disease in our study. An alternative explanation would be that the pulmonary cases had, in fact, because of their more typical symptomatology, been diagnosed and treated prior to pregnancy. This would explain an apparent over-representation of extrapulmonary cases in our population compared with the Indian population, and may explain the low proportion of cases in which tuberculin testing was used as part of the diagnostic work-up, since, as they observe, alternative techniques are required to diagnose extrapulmonary TB. However, it is important to note that more than 50% of the women in our study were of African, notably Somali, origin, and thus different patterns of disease in these countries may also help explain the observed differences.

The perinatal outcomes in our study of women with TB were not significantly different from those of the population as a whole, but given the relatively small number of cases, the study does not have sufficient power to detect, as statistically significant, a difference of the magnitude we found even if it were a real difference. The point estimates together with their confidence intervals (CI) illustrate the broad precision of the estimates of the proportion of women and infants experiencing poor perinatal outcomes: preterm delivery 35% (95% CI 19–55%), severe neonatal morbidity 6% (95% CI 0.7–21%), perinatal death 3% (95% CI 0.1–16%), severe maternal morbidity 9% (95% CI 2–25%) and maternal case fatality 3% (95% CI 0.1–16%).

Nevertheless, we would agree that raised awareness of the disease, the potential for non-specific and varied presentation and the use of tuberculin testing are first steps towards improving outcomes for women and their infants.

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