Figure 5

Patient-based rubella serology results among 15–49 year old females in Ontario with multiple tests by interval between first and last test (N = 82,016 patients, excluding 2,728 patients for whom a different sequence of test results was observed). Among women who had multiple prenatal tests between 2006 and 2010, this figure shows the distribution of women classified according to the sequence of test results, by the number of years between the first and last test. The proportion of women who remained susceptible throughout repeated prenatal testing declined as the number of years between tests increased; conversely, the proportion of women who were initially susceptible and then became immune increased with longer intervals. * Interval refers to 9 months to, 1 year, as tests conducted within 9 months were considered to be associated with the same pregnancy.