Adverse pregnancy outcomes due to Chlamydia trachomatis

Abstract

Joanne Reekie and colleagues1Reekie J Roberts C Preen D et al.Chlamydia trachomatis and the risk of spontaneous preterm birth, babies who are born small for gestational age, and stillbirth: a population-based cohort study.Lancet Infect Dis. 2018; 18: 452-460Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar did a population-based cohort study on the association between a positive test for chlamydia and spontaneous preterm birth, having a baby who is small for gestational age, or stillbirth. On the basis of the findings from their study, the authors concluded that a genital chlamydia infection—presumably treated either before or during pregnancy, regardless of the trimester during which testing occurred—does not substantially increase a woman's risk of having one of these three adverse pregnancy outcomes. Their findings support the continued screening for chlamydia during pregnancy in women who are at a high risk of contracting a chlamydia infection. However, I believe that the implications of these findings for the recommendations on chlamydia screening among pregnant women should be further clarified to address the following issues. First, although a few countries do have national policies, guidelines, or recommendations regarding chlamydia screening among pregnant women,2Joseph Davey D Medline A Klausner JD Screening pregnant women in the 2015 European guideline on the management of Chlamydia trachomatis infections.Int J STD AIDS. 2016; 27: 1134-1136Crossref PubMed Scopus (2) Google Scholar the recommendations on the subgroup of pregnant women that should be included for screening varies across countries.3Workowski KA Bolan GA Sexually transmitted diseases treatment guidelines, 2015.MMWR Recomm Rep. 2015; 64: 1-137Crossref PubMed Scopus (24) Google Scholar, 4Public Health Agency of CanadaCanadian guidelines on sexually transmitted infections.https://www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/canadian-guidelines/sexually-transmitted-infections.htmlDate: 2017Google Scholar, 5Public Health EnglandNational chlamydia screening programme standards.https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/574351/NCSP_Standards_7th_edition.pdfDate: 2016Google Scholar The Centers for Disease Control and Prevention in the USA recommends that pregnant women who are younger than 25 years or women who are older than 25 years and at increased risk for chlamydia infection should be routinely screened for chlamydia,3Workowski KA Bolan GA Sexually transmitted diseases treatment guidelines, 2015.MMWR Recomm Rep. 2015; 64: 1-137Crossref PubMed Scopus (24) Google Scholar whereas the Public Health Agency in Canada recommends the screening of all pregnant women (regardless of their age or risk factors).4Public Health Agency of CanadaCanadian guidelines on sexually transmitted infections.https://www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/canadian-guidelines/sexually-transmitted-infections.htmlDate: 2017Google Scholar However, the National Chlamydia Screening Programme in the UK does not recommend screening during pregnancy as part of routine services.5Public Health EnglandNational chlamydia screening programme standards.https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/574351/NCSP_Standards_7th_edition.pdfDate: 2016Google Scholar Based on their study design and data analyses, evidence from the Reekie and colleagues study1Reekie J Roberts C Preen D et al.Chlamydia trachomatis and the risk of spontaneous preterm birth, babies who are born small for gestational age, and stillbirth: a population-based cohort study.Lancet Infect Dis. 2018; 18: 452-460Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar should favour the screening of all pregnant women, rather than high-risk subgroups. Second, early screening (during the first trimester or first prenatal visit) and retesting for chlamydia during the third trimester3Workowski KA Bolan GA Sexually transmitted diseases treatment guidelines, 2015.MMWR Recomm Rep. 2015; 64: 1-137Crossref PubMed Scopus (24) Google Scholar or during each trimester4Public Health Agency of CanadaCanadian guidelines on sexually transmitted infections.https://www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/canadian-guidelines/sexually-transmitted-infections.htmlDate: 2017Google Scholar in pregnant women who are at increased risk for infection are also recommended. However, the purposes of screening for chlamydia in these two pregnancy stages seem different. Screening during the first trimester aims to prevent the adverse effects of chlamydia during pregnancy (such as preterm birth and stillbirth), whereas retesting during the third trimester (usually defined as weeks 27–40 of pregnancy) aims to prevent maternal postnatal complications and chlamydia infection in the neonate.3Workowski KA Bolan GA Sexually transmitted diseases treatment guidelines, 2015.MMWR Recomm Rep. 2015; 64: 1-137Crossref PubMed Scopus (24) Google Scholar, 6LeFevre ML US Preventive Services Task ForceScreening for chlamydia and gonorrhea: US Preventive Services Task Force recommendation statement.Ann Intern Med. 2014; 161: 902-910Crossref PubMed Scopus (151) Google Scholar With this in mind, assessing the association between chlamydia screening during the third trimester and preterm birth or stillbirth might not be appropriate. By contrast, establishing the risk of chlamydial infections (eg, chlamydia conjunctivitis and pneumonia) for neonates born to mothers tested during the third trimester of pregnancy might improve the recommendations. I have received research funding from the Chinese Academy Medical Sciences Initiative for Innovative Medicine (2016-I2M-3-021). Chlamydia trachomatis and the risk of spontaneous preterm birth, babies who are born small for gestational age, and stillbirth: a population-based cohort studyA genital chlamydia infection that is diagnosed and, presumably, treated either during or before pregnancy does not substantially increase a woman's risk of having a spontaneous preterm birth, having a baby who is small for gestational age, or having a stillbirth. Full-Text PDF