Efficacy of erythromycin in the treatment of inner city pregnant women with cervical Chlamydia trachomatis infection.

In this retrospective study, the efficacy of screening for and treating cervical Chlamydia trachomatis infection was evaluated in a pregnant population at increased risk for chlamydial infection. Over a 2 1/2-year period, 5.75% (338) of the 5,875 women tested were found to be infected with this organism. Of the 323 women patients available for follow-up, 76% (244) were successfully treated and 24% (79) remained infected throughout their pregnancies. Forty (12%) patients became infected during pregnancy, while 26 (8%) were reinfected during pregnancy, despite treatment with erythromycin. Twenty-seven (8%) patients had their first antenatal visit and cervical swab less than a week before delivery. The gestational age at which the first cervical chlamydial swab was obtained was significantly more advanced in patients who remained infected (30.23 +/- 6.2 weeks) than those who were successfully treated (22.15 +/- 7.66 weeks; P = 0.00001). The data suggest that in a pregnant population considered to be at increased risk for C trachomatis infection: (1) there is a subgroup of patients with a high risk of remaining infected or becoming reinfected with C trachomatis during pregnancy despite treatment with erythromycin and (2) repeated prenatal testing and treatment of those infected is necessary to detect and eradicate maternal chlamydial infection.