Babies born in NHS hospitals at the weekend have a slightly greater risk of death within the first seven days, compared with those born during the week, according to researchers.
Study results also suggested increases in the rates of other complications for both mothers admitted and babies born at weekends.
“Babies born at the weekend had an increased risk of being stillborn or dying in hospital within the first seven days”
Previous studies have identified a higher risk of death in patients admitted to hospital on weekends across a range of conditions – a phenomenon termed the “weekend effect”, which has recently become the focus of government policy to create a “truly” seven-day service.
But studies on whether obstetric outcomes are associated with day of delivery have given conflicting results, said the researchers from Imperial College London.
They set out to investigate links between day of delivery and measures of quality and safety of maternity services, particularly comparing weekend with weekday performance.
They analysed details of deliveries in English NHS public services from 1 April 2010 to 31 March 2012 from the Hospital Episode Statistics database. Primary measures were perinatal mortality, infections, emergency re-admissions, and injuries.
Several factors were taken into account, including a mother’s age and ethnic group, socioeconomic deprivation, previous caesarean section, and existing conditions such as diabetes or high blood pressure. Staffing levels were also investigated.
The team found that performance across four of the seven measures was significantly worse for women admitted, and babies born, at weekends.
In particular, the perinatal mortality rate was 7.3 per 1,000 babies delivered at weekends, 0.9 per 1,000 higher than for weekdays. No consistent association between outcomes and staffing was identified.
They estimated that 770 more perinatal deaths per year – from an annual total of 4,500 deaths among 675,000 births – occurred above what would be expected if mortality was always the same as for babies delivered on Tuesday, the midweek reference day.
They also found 470 maternal infections above what would be expected from performance seen for women admitted on the reference day.
“Results also suggest increases in the rates of other complications for both women admitted and babies born at weekends”
The most common day for giving birth was Thursday and the least common was Sunday.
The researchers said: “This study highlights an association between day of delivery and aspects of performance; in particular, babies born at the weekend had an increased risk of being stillborn or dying in hospital within the first seven days.
“Moreover, the results also suggest increases in the rates of other complications for both women admitted and babies born at weekends, with higher rates of puerperal infection, injury to neonate, and three day neonatal emergency readmissions,” they said.
The authors stressed that their work was an observational study so no definitive conclusions could be drawn about cause and effect.
Nevertheless, they said their study represented the most comprehensive assessment of its type of the “weekend effect” in obstetric care.
They suggested that further work was needed “to understand what organisational factors might influence the weekend effect and to investigate centres that have reduced the disparities in access and outcome in out of hours care”.
“A starting point for this would be to allow services to compare how they resource out of hours maternity services and, where data permits, the extent of the weekend effect in their organisation with that of their peers,” they said in the British Medical Journal.
“Appropriate numbers of maternity staff underpin a safe and quality service”
Louise Silverton, director for midwifery at the Royal College of Midwives, said: “The study itself does not give a reason for why these ‘effects’ occur. Midwifery and maternity staffing levels are the same on weekends as they are on weekdays. Midwives work across 24 hours, 365 days per year.
“The authors of this report have a stressed that this study is just an observational study and that no ‘definite conclusions’ can be drawn about the cause and effect of weekend deaths,” she said.
“We need to make sure that we identify the ‘possible causes’ so we can continue to ensure women receive the best possible care for both them and their baby,” she added.
Dr David Richmond, president of the Royal College of Obstetricians and Gynaecologists, said: “The UK is a safe place for women to give birth, however, pressure on maternity services is growing as women are having more complex pregnancies due to the rise in older mothers and maternal obesity.
“Appropriate numbers of maternity staff underpin a safe and quality service and adequate ‘out-of-hours’ senior staffing remains a key issue in maternity care,” he said.
He added: ”This includes appropriate staff training and supervision, ensuring good outcomes outside normal working hours and effective planning and risk management. More robust evidence on the quality of care afforded by different models of labour ward staffing is also required.”