More complex births put strain on maternity services - which struggle more later in the week

NHS Maternity Units are more likely to close towards the end of the week and during holiday periods, pointing to staff availability as a source of pressure. This is a key finding of new research by the Institute for Fiscal Studies (IFS), funded by the Economic and Social Research Council (ESRC), examining sources of short-run and long-run pressures on maternity units in England.

Pressure on NHS maternity services varies over time and by season. Women giving birth today are much more likely to be older and have more complex health conditions than a decade ago. Short-run fluctuations in admissions place pressure on maternity services where capacity is largely fixed. As a last resort Maternity Units may temporarily close to ensure the safety of mothers and babies. While closures do correlate with busy days, they also vary by day of the week and month in ways that do not correspond to spikes in admissions.

Closures are 30% more likely on Thursdays, Fridays and Saturdays than they are on Mondays to Wednesdays. This is despite the fact that admissions are evenly spread across week days and are lower at weekends. There are 50% more closures in June than January, even though the number of births is roughly the same.

Other key findings include:

One in ten maternity units closes more than six times each year, but overall closures are not common - each maternity unit closes temporarily about twice a year on average. Closures are more common during (generally unpredictable) busy periods, but the end of week and holiday period peaks in closures are predictable and point to staff shortages creating problems.

Pressure on maternity services has not been created by more births. The number of women giving birth in the UK each year has barely changed over the last eight years. However increasing average maternal age and greater obesity rates, tend to result in women requiring greater levels of care when giving birth. Births to women aged 40 or over have increased 25% over the past decade. The numbers of women recorded as obese when they give birth or with other complex health needs have also risen.

These changes in the characteristics of mothers are entirely responsible for the increased number of C-sections. Between 2006 and 2014 the annual number of procedures rose by 23,000. This does not appear to reflect changes in medical practice, rather it reflects changes in the demographic and health characteristics of mothers giving birth resulting in more complex pregnancies.

Elaine Kelly, a Senior Research Economist at IFS and an author of the study said:

"NHS Maternity Units are more likely to close towards the end of the week and during holiday periods, pointing to staff availability as a key problem. Such closures may be the most cost efficient way of dealing with pressures but NHS Hospital Trusts should certainly ensure that such day-of-the-week or seasonal effects are an understood and tolerable consequence of financial restraint, rather than the result of poor workforce management. More generally while the number of women giving birth in the UK is not increasing, NHS Maternity Units are under increasing pressure from the fact that those giving birth increasingly have characteristics associated with, on average, more expensive care needs."

Notes to editors

1. "Under pressure? NHS maternity services in England" by Elaine Kelly and Tom Lee will be published on the IFS website ifs.org.uk at 00.01 Monday 11th of September and is embargoed until that time. The work will be presented at the IFS event “NHS services in the face of increasing demand - what does it mean for patients?” on September 11th 2017.

2. For embargoed copies, or if you have any questions, please contact Thomas Hauschildt in the IFS press office: @email / 020 7291 4800 / 07730 667 013.

3. This research was funded by the ESRC Centre for Microeconomic Analysis of Public Policy (CPP) at IFS. Elaine Kelly would like to thank the ESRC for funding through a Future Leaders grant (ES/K009060/1). The authors thank NHS Digital for access to the Hospital Episode Statistics under data sharing agreement CON-205762-B8S7B