Efficacy of cytology for the diagnosis of Chlamydia trachomatis in pregnant women.

This study evaluated the effectiveness of Papanicolaou staining for the initial diagnosis of Chlamydial infection in pregnant women. A hundred thirteen patients were examined with a Papanicolaou test, independent of gestational age, parity or maternal age. Three endocervical samples were collected; the first two were collected with a brush (Cytobrush plus, Mediscand, Sweden) and the third with Ayre's spatula. The first specimen was used for McCoy cell culture and the other two were examined cytologically. Chlamydial infection was detected in 9 (7.9%) patients. Only one (0.8%) was diagnosed by cytological exam. The sensitivity and specificity of the cytological examination were 10 and 98%, respectively. The estimated positive predictive value was 33.3% and the negative predictive value was 92.7%. When Papanicolaou stain diagnosis suggests Chlamydia, a more specific complementary exam should be added to confirm infection; subsequently adequate treatment can be implemented, thereby preventing the frequent complications of untreated subclinical infections.