Is it time for the UK to reconsider its definition of recurrent miscarriage?

When we meet patients who have had a miscarriage, they generally ask the same questions. Why did it happen? Will it happen again? And can it be stopped?

Here at the University of Birmingham, we work on answering those questions for our patients. We lead clinical trials to find interventions that could give effective treatments to families experiencing the heartbreak of miscarriage.

Over 15% of all recognised pregnancies result in miscarriage, and thousands of families across the UK are affected by repeated pregnancy loss. It is estimated that 5% of women experience two consecutive miscarriages, and approximately 1% suffer three or more consecutive miscarriages.

Although individual healthcare professionals make every effort to support all of their patients, many women and couples feel dismissed and unsupported by medical services with protocols to withhold detailed investigations and interventions before at least three miscarriages. This is because ‘the loss of three or more consecutive pregnancies’ is necessary to diagnose recurrent miscarriage according to national guidelines published by NICE and the Royal College of Obstetricians and Gynaecologists (RCOG).

Whilst the risk of miscarrying again increases sequentially in women experiencing one and two miscarriages, the risk of subsequent miscarriage is not significantly increased any further among those with three losses. Therefore many experts now believe women should be investigated after two events.

Some medical authorities beyond the UK have already moved to change their guidelines.

In 2007, NVOG (the professional body for obstetricians and gynaecologists in the Netherlands) redefined recurrent miscarriage as ‘two or more objectified miscarriages’. More recently, the American Society for Reproductive Medicine (ASRM) made a similar change.

Currently, the European Society of Human Reproduction and Embryology (ESHRE) defines recurrent miscarriage as three or more consecutive losses, but is considering whether or not to change this definition.

The issue is contested and it remains to be seen whether UK guidelines will follow suit in the near future.

But in the meantime, the national network of researchers that we are building, through multicentre trials such as PROMISE, RESPONSE, PRISM and TABLET, will put us in a position to contribute to the debate, and allow us to make better informed decisions about how we define and treat recurrent miscarriage.

This is important because - notwithstanding the physical effects of miscarriage and the emotional trauma it brings for many women - all too often the end of pregnancy signals the end of medical attention, such that many couples who miscarry find themselves bereft of tools and resources to make sense of the lived experience.

In Birmingham we aim to put the priorities of women and their partners at the heart of what we do, to answer questions that deserve to be answered.

Professor Arri Coomarasamy, Institute of Metabolism and Systems Research

Helen Williams, Research Associate