To obtain an approximate idea of the frequency of tuberculosis during pregnancy we assume in the absence of data that it is about the same as among women of the child-bearing age. From 25 to 29 per cent, of all women in this age period die of tuberculosis and the general death-rate for the period is 8 per thousand. Consequently the yearly death-rate from tuberculosis for women between the ages of 15 and 50 is from 2 to 2.3 per thousand. Now, assuming an average duration of the disease of from five to eight years this would give a frequency between 1 and 2 per cent. This would indicate that every year there are in the United States between 22,000 and 44,000 gravidæ with active tuberculosis in one of the three stages.
Probably if all latent cases were included the number would be greater. I omit consideration of such cases