Baby boys are more likely to be stillborn than girls, a new study has found.

UK researchers reviewed over 30 million births worldwide and found that the risk of a stillbirth was 10% higher in boys. Globally, this is a loss of some 100,000 additional baby boys every year.

"The numbers speak for themselves - the disparity between male and female stillbirth rates is startling. Stillbirth is a common occurrence, even in rich countries with good healthcare systems. Uncovering why male babies are at higher risk could be a first step towards developing new approaches to prevention, including sex-specific management of high-risk pregnancies," commented researcher, Dr Fiona Mathews, of the University of Exeter.

The study noted that while the overall incidence of stillbirths was lower in high-income countries, the increased risk among baby boys was consistent in both high and low-income countries.

The researchers said that the reason for the findings are unclear, however they suggested that male foetuses could have increased sensitivity to environmental factors affecting the mother, such as smoking, obesity and social deprivation.

They added that while it is essential to closely monitor the growth of a baby in the womb, as this can provide an early warning about the risk of stillbirth, the baby's gender is rarely taken into account.

Since male babies tend to be larger than females, this could help to identify unusually small male babies at high risk.

Details of these findings are published in the journal, BMC Medicine.

In Ireland, around 360 stillbirths are registered every year. Information and support is available from Féileacáin, the Stillbirth and Neonatal Death Association of Ireland here