UK trial investigates whether antibiotics could cut miscarriage likelihood

UK researchers are beginning a trial investigating whether a course of antibiotics prior to conceiving could cut likelihood of miscarriage in up to half of cases.

A team at the University of Warwick, in partnership with University Hospitals Coventry and Warwickshire NHS Trust is conducting the trial, which has received £1.9 million in funding from the Efficacy and Mechanism Evaluation (EME) Programme, a partnership between the Medical Research Council and the National Institute for Health Research.

It will involve over 3,000 women in NHS hospitals in the United Kingdom who have recurrent miscarriage and was launched earlier this month at the British Science Festival, this year held in partnership with the University of Warwick.

The first part of the new approach is to test for endometriosis, inflammation of the lining of the womb, that has been linked with miscarriage and is commonly treated with the antibiotic doxycycline.

Researchers suspect that endometritis may be caused by an imbalance of the bacteria (microbiome) that live in the reproductive tract.

A healthy endometrium is important for the embryo to be able to attach to the womb and it is thought that endometritis disrupts this process, and can lead to a miscarriage.

Treating endometritis with antibiotics may reduce symptoms by killing disruptive bacteria and allowing the healthy bacteria to grow.

To find out if doxycycline can reduce miscarriage and increase the number births in women who have experienced two or more early miscarriages, the researchers will carry out a double blind randomised controlled trial, by comparing a 14-day course of doxycycline against a placebo. Women will be advised to start trying to conceive once they have finished the course.

The trial will also use a complex adaptive design originally developed for cancer trials at the University of Warwick.

During the trial, information will be analysed at regular intervals to see if the trial can be stopped early if results are greater than expected. In addition, the results will be presented as the probability that the treatment works and in which patients it works, rather than a simple yes or no answer.

Warwick Medical School’s Professor Siobhan Quenby, Principal Investigator on the trial, said: “This is potentially a new treatment for up to half of people with recurrent miscarriage. We know that doxycycline is given to some women experiencing miscarriage in other countries, but there has never been a proper trial conducted.

“And instead of just having your blood tested to look for causes of miscarriage, as is current practice, you will have the lining of the womb tested too so that we can identify those who will benefit from this treatment.

“Our aim is to try to improve the womb before you get pregnant. Most miscarriages occur within the first trimester (12 weeks) of pregnancy and our aim is to see a reduction in these early miscarriages.”