Women who have had the common sexually transmitted infection chlamydia are more likely to have an ectopic pregnancy due to lingering effects of infection, Scottish scientists have revealed.
Researchers at Edinburgh University have found evidence that women who had contracted the infection were more likely to produce a protein, called PROKR2, in the Fallopian tube.
Production of this protein makes an embryo more likely to implant outside the womb, in the Fallopian tube. Ectopic pregnancies, in the vast majority of cases, are not viable, are dangerous for the pregnant women and can even be fatal.
Chlamydia is already known to cause infertility because it can lead to scarring and blockages in the Fallopian tube, which can prevent an egg travelling from the ovary to the uterus. But this research shows that the damage can be more insidious, increasing risks of ectopic pregnancy even if there are no signs of scarring.
The researchers say that the study, published in the American Journal of Pathology, adds weight to public health messages on safer sex and chlamydia testing.
Dr Andrew Horne, of the university’s Centre for Reproductive Biology, said: “We know that chlamydia is a major risk factor for ectopic pregnancy but until now we were unsure about how the infection led to implantation of a pregnancy in the Fallopian tube.
“We hope this new information allows healthcare providers to give women accurate information about risks following chlamydial infection and to support public health messages about the importance of safer sex and chlamydia testing.”
Around one per cent of pregnancies are ectopic. This study follows on from other Edinburgh University research which showed that smokers were more likely to have an ectopic pregnancy, also because of production of this particular protein.
The study was funded by the Wellbeing of Women charity and the Medical Research Council.