New Research published in the Journal of Sexually Transmitted diseases indicates that infection with chlamydia or gonorrhoea in the lead up to or during pregnancy can increase the risk of complications such as stillbirth or premature birth.

For the study researchers analysed the birth records of over 350000 women between 1999 and 2008 in New South Wales. The main question they wanted to answer was whether these infections had an impact on either the baby or the birth itself, as this is still being debated.

They found that among the women in the sample at least 1% had had one documented chlamydia infection before the birth and most of these, 81% had been diagnosed before the estimated due date of conception. In comparison just 0.6% had been diagnosed with gonorrhoea before the birth with just under 85% of diagnosis made, before the estimated date of conception.

In all, 4% had unplanned premature birth, 12% had babies small for dates and 0.6% of the babies were stillborn. Other factors that played a role were social disadvantage, smoking and diabetes and high blood pressure, but even when all of these factors were taken into account those with prior chlamydia and gonorrhoea infection still had an elevated risk.

Women with chlamydia for instance had a 17% increased risk of unplanned premature birth and 40% increased risk for having a stillborn baby

Women with gonorrhoea were more than twice as likely to have unplanned premature birth. As there were not enough women with gonorrhoea infection in the sample they could not comment on the risk of stillbirth in this population. In the chlamydia sample the risk did not differ depending on when they contracted the disease.

Looking at this study I think it is difficult to draw straightforward conclusions from the figures , as the infections might just be a marker for women at high risk of birth complications, and the study authors noted this too.

They do however conclude that “sexually transmittable infections in pregnancy and the pre conception period may be important in predicting adverse obstetric outcomes”

I would advise anyone considering pregnancy to have a full sexual health screen beforehand to rule out any infections.