All women who presented for delivery at the University of California, San Diego Medical Center between January 1, 1990, and June 30, 1991, who did not have a documented TBN-ST were eligible to be included in the study. Since a TBN-ST is included in routine prenatal screening, this group consisted almost entirely of women who had no prenatal care.
As soon as possible after admission to the labor and delivery area, each woman was given a questionnaire, the purpose of which was to identify patients who had a past history of a positive TBN-ST, past history of exposure to tuberculosis or recent symptoms compatible with active tuberculosis (Fig 1). Each patient who had any positive response to this questionnaire received a chest roentgenogram before having contact with her baby. We initially were concerned about placing too much of a demand on the time of the nurses so these patients did not receive a TBN-ST, since each of these patients were to receive a chest roentgenogram. (There turned out to be relatively few women with positive symptom questionnaires, so we currently do perform a TBN-ST in addition to a chest roentgenogram on women with a positive symptom questionnaire.)
All women who had no positive response to the questionnaire had a TBN-ST given by the Mantoux technique. Five tuberculin units of purified protein derivative (PPD) (Connaught Laboratories Limited, Willowdale, Ontario, Canada) was injected intradermally into the volar aspect of the forearm, almost always within an hour of admission to the labor and delivery area. The date and time of injection was recorded. The injections were performed by the labor and delivery nurses, all of whom had been trained in the technique.
Figure 1. Symptom questionnaire given to each patient upon admission to die labor and delivery area.