• CHLAMYDIA INFECTION
• PREGNANCY
• SCREENING

Infection with Chlamydia trachomatis can lead to complications of the reproductive tract and adverse pregnancy outcomes. There is no national screening programme for detection of chlamydia in pregnancy. However, our antenatal clinic offers chlamydia screening to all patients at their first antenatal visit in order to prevent complications in pregnancy following the guidance from National Chlamydia Screening Programme in England and Centres for Disease Control and Prevention.1 A case note review was undertaken to determine the value of this practice.

A retrospective cases note review of all patients who were referred from 1 July, 2012 to 30 June, 2013 from the antenatal clinic to the sexual health clinic with positive urinary chlamydia results was undertaken. Complete sexual health screen, including endocervical swabs for gonorrhoea and repeat chlamydia were obtained. Chlamydia was detected using the nucleic acid amplification tests. Treatment and partner notification was commenced simultaneously.

Urine tested positive in 24 women (age range 21–36 years) in antenatal clinics. Endocervical swabs were reported positive in 18 (75%) women on repeat chlamydia testing. Therefore, a false positive result was diagnosed on urine screening in six (25%) women. The partners of these six patients, all of whom were in stable relationships, were diagnosed negative for chlamydia. Unfortunately, two of the patients reported a temporary breakdown of long-term relationship, and one made a complaint, as possibility of false positive results was not explained to them prior to screening.

First-catch urine samples may be less sensitive than endocervical swabs for the detection of C trachomatis.2 In our cohort, screening of urine resulted in increased sensitivity that led to false positive results, the cause of which is not known. This may be due to missed urethral infections when endocervical site alone is sampled.3 Isolated urethral infections are common in women, and in pregnancy, where endocervical swabs alone may be subsequently negative.

There is no evidence to support cost-effectiveness of universal chlamydia screening in pregnancy in the UK.4 Chlamydia screening as part of routine antenatal care was considered highly acceptable among pregnant women who recognised the benefits of screening.5

The psychological, emotional and social consequences of a positive chlamydia result in pregnancy should be considered before arranging such investigations. Retesting of all positive urine tests in pregnancy may be a good alternative to reconfirm the results. Further study of chlamydia test results in pregnant women is needed to evaluate the cause of increased sensitive results.