Weekends are associated with a higher rate of complications for births in hospitals in England, a study has found.

Researchers at Imperial College London looked at over 1.3 million births that took place in NHS services in England between 1 April 2010 and 31 March 2012.

The research, which is published in the BMJ, found that the rate of maternal infections and perinatal death (defined as a baby being stillborn or dying in hospital within seven days of birth) varied according to the day of the week on which a woman gave birth. The rates of injury to the baby during birth, and emergency readmission of the baby to hospital within three days of birth, were also different on different days of the week.

The rate of perinatal death was found to be highest on a Thursday, followed by Saturday and Sunday. The lowest day was a Tuesday. 

Most births were found to occur on a Thursday, and fewest on a Sunday.

The researchers compared rates of complications on weekdays with rates at weekends, adjusting for factors including gestational age, birth weight, maternal age, and any pre-existing health conditions in the mother such as diabetes or high blood pressure. 

The rate of perinatal death on weekdays was 6.5 per thousand babies delivered. The rate of perinatal death across babies born on Saturday and Sunday was 7.1 per thousand.

 In addition to this, the team found that mothers admitted at the weekend had slightly higher rates of infections compared to weekdays (8.7 infections per thousand deliveries, compared to 8.2 per thousand). 

The authors suggest that if rates of perinatal death and maternal infections were the same across the week as they were on a Tuesday, there would be 770 fewer perinatal deaths a year, and 470 fewer maternal infections. There are around 4,500 perinatal deaths every year in England across 675,000 births. 

The rate of injury to the baby during birth was also found to be slightly higher across those delivered on Saturdays and Sundays compared to a weekdays (15.3 per thousand births compared to 14.5 per thousand).  The days that had the lowest rate of injury to the baby during birth were Wednesday and Thursday.

The rate of emergency readmissions for the baby within three days of birth was also higher for babies born on a Saturday and Sunday compared to weekdays (12.3 per thousand births compared to 11.8 per thousand births).

In a second part of the study, the team investigated whether there was a link between birth complications and the recommended consultant staffing levels in labour wards. No association was found between consultant staffing levels and complications such as perinatal death or injuries to the baby during birth. The only area in which an association was found was in perineal tears, where the rate was 3.0 per cent in wards that complied with consultant staffing levels, compared to 3.3 per cent in units that didn’t comply. 

The team cautioned they were only able to look at data up to 2012, and so current data may reveal a different picture.

Professor Paul Aylin, from the School of Public Health at Imperial, and who was the senior academic on the team, said: “In our paper we tried to account for the fact that differences in rates of complications on different days may be due to chance, or that births on certain days are more complicated in some way. However, even after making these adjustments, we found the rates of complications vary on different days. We don’t know what causes this difference, and when we looked at consultant staffing levels we didn’t see a strong link between reduced staffing and complications. More work needs to be done to better understand the causes of these differences, so that steps can be taken to improve outcomes for mothers and babies. Maternity care involves a whole team including midwives and other medical staff, so one avenue for future research might be to look at staffing levels beyond consultants.”

Professor Aylin discusses the research in more detail in the video below.

Dr William Palmer, lead author and honorary research fellow from the School of Public Health, added: “We have been able to present a detailed and comprehensive assessment of the ’weekend effect’ in this important area of healthcare. However, this is a study based on administrative data and so we did not observe the quality of care directly.

The public should reasonably expect high quality care at all times, and this paper suggests that managers and clinicians in maternity care need to seek further assurance that their services are providing consistently good care throughout the week."

The study was conducted at the Dr Foster Unit at Imperial, funded by Dr Foster (a Telstra Health company) and the National Institute for Health Research. 

"Association between day of delivery and obstetric outcomes: observational study" is published in The BMJ.