Giving birth outside of working hours in England is safe, study shows

A new study has suggested that between 2005 and 2014, for almost all births in England, being born outside of working hours did not carry a significantly higher risk of death to the baby from anoxia (lack of oxygen) or trauma.

The findings run contrary to an assumed wider ‘weekend effect,’ with previously reported research suggesting a significantly higher risk of death for births outside working hours or at weekends.

The new study from City University in London linked together a large body of data from health services and official statistics, relating to over six million births during a ten year period.

This allowed the researchers to stratify births by how the labour started, type of birth, time of day, and day of birth, as well as taking account of obstetric risk factors.

The study excluded stillbirths from the analysis. The authors said more than 90 percent of stillbirths are known to occur prior to the onset of labour and are therefore unlikely to be affected by care at birth. In the majority of the remaining cases it is unknown whether the stillbirth occurred before or during birth.

Stillbirths had been included in a previously published study of 1.3 million births in England, which looked at the day of the week of the birth, but not time of day, and which concluded that the rate of stillbirth, death during pregnancy, or death in the first week after live birth was higher at weekends.

A previous study in Scotland of over a million births excluded stillbirths and included the time of day of birth in its analysis of deaths in the first month after live birth. It concluded that rates of death were higher outside working hours during the week compared to working hours.

However, the City University researchers said neither of these studies was large enough to provide the sufficient detail needed to identify the small subgroup of births with a higher risk of death to the baby found in the new study of births in England.

The new study found that for two percent of births in England – births by emergency caesarean without labour – being born outside working hours brought a 1.5-fold higher risk of death to the baby from anoxia or trauma compared to births during working hours.

As the death of a newborn is a rare event, this higher relative risk nonetheless translates to a low absolute risk (an estimated 46 deaths of newborn babies over the ten year study period).

The study recommended that based on this evidence, attempts to reduce risk should focus on this smaller subset of emergency births rather than regarding all out of hours births as dangerous. It recommended further research should focus on understanding who goes on to have an emergency caesarean birth without labour, and what aspects of care in the community or in hospital can help prevent critical incidents arising.

Alison Macfarlane, Principal Investigator of the study and professor of perinatal health at City University, said: ‘These findings are very reassuring and demonstrate the benefits of using a very large, linked dataset. They show that attention should shift from the timing of birth to identifying this very small subgroup of highly vulnerable women and the measures required to meet their needs.’

Image: Carlo Navarro