Chlamydia and gonorrhoea infections and the risk of adverse obstetric outcomes: a retrospective cohort study
- 1University of New South Wales, Sydney, New South Wales, Australia
- 2The Sax Institute, Sydney, New South Wales, Australia
- 3Clinical and Population Perinatal Research, Kolling Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia
- 4Grafton Base Hospital, Grafton, New South Wales, Australia
- 5Centre for Health Research, University of Western Sydney, Campbelltown, Australia
- 6Aboriginal Health and Medical Research Council, Sydney, New South Wales, Australia
- 7Baker IDI Central Australia, Alice Springs, Northern Territory, Australia
- Correspondence to Dr Bette Liu, University of New South Wales, Sydney, NSW 2052, Australia;
- Received 5 March 2013
- Revised 23 June 2013
- Accepted 20 July 2013
- Published Online First 4 September 2013
Objectives To examine the association between prior chlamydia and gonorrhoea infections and adverse obstetric outcomes.
Methods Records of women resident in New South Wales, Australia with a singleton first birth during 1999–2008 were linked to chlamydia and gonorrhoea notifications using probabilistic linkage. Obstetric outcomes and potential confounders were ascertained from the birth record. Logistic regression, adjusted for potential confounders was used to estimate the association between a disease notification prior to the birth and adverse birth outcomes: spontaneous preterm birth (SPTB), small for gestational age (SGA) and stillbirth.
Results Among 354 217 women, 1.0% (n=3658) had a prior chlamydia notification; 0.06% (n=196) had a prior gonorrhoea notification. The majority of notifications (>80%) occurred before the estimated conception date. 4.1% of women had a SPTB, 12.1% had a SGA baby and 0.6% of women had a stillbirth. Among women with a prior chlamydia notification, the risk of SPTB and stillbirth was increased, aOR 1.17 (95% CI 1.01 to 1.37) and aOR 1.40 (95% CI 1.00 to 1.96) respectively but there was no association with SGA, aOR 0.99 (95% CI 0.89 to 1.09). For women with gonorrhoea the risks for SPTB, stillbirth and SGA were respectively aOR 2.50 (95%CI 1.39 to 4.50), 2.35 (95% CI 0.58 to 9.56) and 0.98 (95% CI 0.58 to 1.68). Among women with a prior chlamydia diagnosis, the risk of SPTB did not differ between women diagnosed >1 year prior to conception, within the year prior to conception or during the pregnancy, (p=0.9).
Conclusions Sexually transmissible infections in pregnancy and the preconception period may be important in predicting pregnancy outcomes.