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Updated: 1 hour 31 min ago

Babies born on the weekend have slightly higher death risk

Wed, 2015-11-25 03:30

"Babies delivered at the weekend are significantly more likely to die or suffer serious injury," the Daily Mail reports. 

However, while the increase in risk is both significant and an obvious cause for concern, it should be noted that it is a very small increase.

Researchers looked at the outcomes of 1,349,599 births in the two years from April 1 2010, and found that an estimated 770 extra deaths occurred each year above what would occur if all babies were born on weekdays.

Obviously, 770 extra deaths is 770 too many, but it is important to put the figure into a larger context. When we look at the actual numbers, 0.73% of babies born at the weekend died, compared to 0.64% of babies born on weekdays.

While it may be tempting to assume that the extra deaths are all down to staffing issues (e.g. consultants not working at weekends) other factors may be involved. For example, most women giving birth by planned caesarean section did so during the week. Babies born this way may be lower risk, which could make the weekday births appear safer.

The study highlights that the overall risk of infant death is very low. However, the small difference in risk between those born on the weekend and on weekdays cannot be ignored.

The study raises important questions about the provision of maternity services at weekends, and whether changes to staff availability and resources might reduce the numbers of deaths among babies born at the weekend.


Where did the story come from?

The study was carried out by researchers from Imperial College London and the National Audit Office, and was partially funded by Imperial College London’s research centre. The study was published in the peer-reviewed British Medical Journal (BMJ) on an open-access basis, which means it is free to read online.

The tone of the reporting varied sharply between different media outlets. The Daily Mirror went with the powerful headline: "Betrayal of our babies as weekend births puts hundreds of mums and newborns at risk". The emotive headline was followed by a story that misreported the study’s figures. The report said that 770 babies delivered at the weekend die each year, when that is the estimated increased number of deaths each year, compared to if all babies were born during the week.

The Guardian took a more measured approach, with "Weekend-born babies slightly more likely to die in their first week", and like most other media sources, reported the study accurately and with context.

Unsurprisingly several sources, including the Daily Mail, The Daily Telegraph and BBC News, linked the study to the ongoing dispute between the government and junior doctors, over changes to doctors' contracts that would affect weekend working.

The dispute was further inflamed by a recent controversial study, published in the BMJ in September, which estimated that there were an extra 11,000 "weekend deaths" during 2013-14. 

However, the researchers themselves warned: "It is not possible to ascertain the extent to which these excess deaths may be preventable; to assume that they are avoidable would be rash and misleading".


What kind of research was this?

This is an observational study which used a database of NHS statistics to look for differences in outcomes between babies born during the week and at the weekend.

Previous studies across various medical conditions have suggested that people admitted to hospital at the weekend have increased risk of death and other adverse outcomes, compared to if admitted on a weekday.

This study aimed to see whether the association may also be found in maternity care. However, a study of this nature cannot say what has caused these differences.


What did the research involve?

The researchers used a large database of NHS statistics to find information about outcomes for women and babies in English maternity units.

They looked at seven outcomes they said could be linked to quality of care, including overall infant mortality around the time of birth (including stillbirths and deaths within seven days), tears to women’s perineum (the area between the anus and the vulva), emergency re-admissions for mother or baby, and infections. They looked at rates of these outcomes on each day of the week, and compared weekend rates to overall weekday rates.

The researchers chose Tuesday as a "reference day", because women admitted in labour on a Tuesday are likely to give birth during the week, and babies born on Tuesdays are not likely to have been born after a labour starting at the weekend. 

They compared weekend outcomes to outcomes on a Tuesday, after taking account of a number of factors (confounders) that might have affected the results. These included the mother’s age, and the baby’s gestational age and birth weight. They then calculated how many extra deaths are likely to have occurred at the weekend, compared to if all births had the same risks as those happening on Tuesdays.

A number of checks and adjustments to the figures were carried out to try to account for missing information and for other things that could have affected the results. They also looked to see whether maternity units which complied with recommendations about how many hours consultants should be present had better outcomes than units which did not comply with these recommendations.


What were the basic results?

Overall, 0.73% of babies born at the weekend died around the time of birth, compared with 0.64% of babies born during the week. In other words, this meant that babies born at weekends had a 7.3 in 1,000 chance of dying, compared to babies born during the week, who had a 6.4 in 1,000 chance. After taking account of factors that could explain the difference, this means that babies born at the weekend had a 7% greater chance of death (odds ratio (OR) 1.07, 95% confidence interval (CI) 1.02 to 1.13).

Mothers had a 6% higher chance of getting an infection after giving birth if they were admitted at the weekend (95% CI 1.01 to 1.11), and babies had a 6% higher chance of being injured during birth if they were born at the weekend (95% CI 1.02 to 1.09). 

There was a suggestion of a marginally increased chance of the baby being re-admitted as an emergency after a weekend birth, but this just fell short of statistical significance (OR 1.04, 95% CI 1.00 to 1.08). None of the other three outcomes measured showed a statistically significant difference between weekends and weekdays.

Women giving birth in hospital units which met the Royal College of Obstetricians and Gynaecologists’ guidelines on consultant staffing levels were slightly less likely to have a perineal tear, but consultant levels showed no other differences in outcomes.


How did the researchers interpret the results?

The researchers said their study had shown that "performance across four of the seven measures was significantly worse for women admitted, and babies born, at the weekend". They highlighted the increase in stillbirths or deaths within seven days of birth as being of particular concern.

They say that "further work is needed" to understand what lay behind their findings, and concluded: "Unless managers and practitioners work to better understand and tackle the problems raised in this paper, health outcomes for mothers and babies are likely to continue to be influenced by the day of delivery". 



The media headlines resulting from this study sound alarming and could be worrying for pregnant women and their partners. However, there are some good reasons to be cautious.

Firstly, it's important to keep in mind that it is unusual for babies to be stillborn or die within a few days of birth. It is devastating when it does happen, but the risk is low. In this study, this happened to around seven in every 1,000 babies born at the weekend and six in every 1,000 born on a weekday. Therefore, the absolute risk is very low, but the small difference in rates between weekends and weekdays cannot be ignored.  

The biggest difficulty is that we don't know what is behind the increased chances of certain problems at the weekend. We cannot say it is simply because care is less good in hospitals than during the week.

There are a number of important limitations to the study’s results. The database used, the Hospital Episode Statistics database, should include information about what happened to people from their admission to the maternity unit onwards. 

However, the researchers found that much of the information they looked for was missing, including information about babies' birth weight (missing in almost 10% of cases) and whether they were born at full term (missing in 13% of cases). These are important factors that can affect whether a baby dies, and may have nothing to do with the care they receive during birth.

The timing of admission and birth may also have affected the results. Babies were counted as having been born at the weekend if they were born between midnight on Friday and midnight on Sunday, although their mother may have been admitted in labour before then. Women were counted as having been admitted at the weekend if they were admitted between midnight on Friday and midnight on Sunday, although they may have given birth after then.

This means that babies who died might have been classified as having been born at the weekend, even though the problems leading to their death might have happened during labour on the Friday.

Conversely, mothers who had problems after being admitted at the weekend might not have encountered those problems until giving birth on the Monday.

Although the researchers tried to make allowances for these issues, the amount of missing information from the database makes it harder to rely on the results.

Another issue is the effect of planned caesarean births, which are almost always planned for a weekday.

Professor Andrew Whitelaw, of the University of Bristol, said planned caesareans represented "low-risk babies" because there is almost no risk of the baby being starved of oxygen or physically injured during birth, and that the large numbers of planned caesareans during the week might lead to a reduced death rate on weekdays. 

In an editorial published with the study, two professors of obstetrics and gynaecology from Oregon, in the US, conclude that "the most likely mechanism underlying the weekend effect is systems factors (such as staffing, resource availability, hospital policies)". This may be the answer, at least in part, as has been suggested with other areas of medical or surgical care. However likely this may be, the study does not provide evidence to prove this is the case. 

The availability of consultants did not seem to make a big difference to the outcomes, although we don’t know whether the numbers of nurses, junior doctors and midwives available might have made a difference.

Overall, this study raises a lot of questions about why certain outcomes, especially deaths of babies, were more common when babies were born at the weekend. We need more research to find out the answers.

Links To The Headlines

Risk of having a weekend baby: Major study reveals greater threat of stillbirth or death. Daily Mail, November 25 2015

Babies born at weekends 'have higher death risk'. BBC News, November 25 2015

Babies more likely to die if born in NHS hospitals at weekend. The Daily Telegraph, November 24 2015

Babies born at weekends 'more likely' to be stillborn or die in first week of life. The Independent, November 24 2015

Betrayal of our babies as weekend births puts hundreds of mums and newborns at risk. Daily Mirror, November 24 2015

Weekend-born babies slightly more likely to die in their first week. The Guardian, November 24 2015

Babies born in NHS hospitals at weekends 'have lower survival rate'. ITV News, November 25 2015

Links To Science

Palmer WL, Bottle A, Aylin P. Association between day of delivery and obstetric outcomes: observational study. BMJ. Published online November 24 2015

Categories: News

Loneliness 'may affect the immune system'

Tue, 2015-11-24 06:30

"Being lonely won't just make you miserable; it could also suppress your immune system and knock years of your life," the Daily Mail reports. 

This headline was prompted by a laboratory study in humans and rhesus macaque monkeys, which aimed to investigate if there were biological mechanisms associated with isolation that could also be associated with the risk of chronic disease or early death.

The findings suggest increased activity of the sympathetic nervous system – responsible for the "fight or flight" response – may overstimulate development of inflammatory white blood cells in the bone marrow. At the same time it may decrease the production of antiviral proteins, reducing the body's ability to fight infections.

However, at this stage this is still just a hypothesis. The study has not directly demonstrated that people who are socially isolated are more likely to become ill or die earlier and the immune system played a key role.

Loneliness and social isolation can be complex emotions, and it may be difficult to pin down a single causative factor. It could be a cycle where people with a chronic disease may be less motivated to socialise with others, increasing the sense of isolation, and so on.

Many people in the UK – particularly older adults – can be lonely and socially isolated. But there are ways to combat loneliness, both by seeking help if you are lonely and by helping lonely and isolated people in your community.   

Where did the story come from?

The study was carried out by researchers from the University of California and the University of Chicago, with financial support provided by the US National Institutes of Health.

It was published in the peer-reviewed scientific journal PNAS on an open-access basis, so it is free to read online or download as a PDF.

The UK media's reporting of the research was generally accurate, but could have benefited from making it clearer that we don't know whether these findings provide the whole answer.

Also, although this study looks at a previously observed concept, it hasn't demonstrated that people who are lonely or isolated are more likely to become ill or die earlier.  

What kind of research was this?

This laboratory study in humans and rhesus macaque monkeys aimed to investigate the cellular effects of loneliness. Various studies have already linked social isolation in humans to chronic disease and mortality, though the possible biological mechanism behind this has remained poorly understood.

In humans, feeling socially isolated can involve feeling threatened and being hyperalert. Humans evolved to live in groups with other humans, so prolonged isolation may, on an unconscious level, trigger feelings of profound unease about potential threats: if all of your tribe has suddenly vanished, you could be in a lot of trouble.

Animal models have shown the response to a threat involves signalling from the sympathetic nervous system (SNS) – responsible for the "fight or flight" response – to the bone marrow, where new blood cells are produced.

SNS signalling is thought to increase the activity of "pro-inflammatory" genes, which stimulate the development of early-stage myeloid blood cells in the bone marrow. These myeloid cells give rise to various types of white blood cells (involved in fighting infection), as well as red blood cells and platelets.

It is thought increased myeloid stimulation could contribute to inflammation-related chronic diseases. Meanwhile, while increasing the activity of pro-inflammatory genes, SNS signalling is thought to decrease the activity of genes involved in the production of antiviral immune proteins.

This process is called the conserved transcriptional response to adversity (CTRA) and is associated with specific gene activity, known as CTRA gene expression. This study aimed to find further evidence of the possible links between perceptions of social isolation and sympathetic nervous system effects on the myeloid cells and the CTRA.       

What did the research involve?

The research involved groups of humans and rhesus macaques, and looked at how perceived isolation was associated with measures of immune blood cells and CTRA gene expression.

The human study involved 141 people taking part in the Chicago Health, Aging and Social Relations Study (CHASRS). About a quarter of these people perceived themselves to be highly socially isolated, based on their scores on a loneliness scale during the first five years of the study.

The current research involved blood samples collected from these people during study years 5 to 10. The researchers looked at white blood cell count and CTRA gene expression. Urine samples were also collected to measure the "fight or flight" hormones adrenaline and noradrenaline, and the stress hormone cortisol.

The researchers looked at the association between these biological measures and the score on the loneliness scale, taking account of various potential confounding factors, including age, gender, marital status, income and lifestyle factors.

The macaques were classified to have low, intermediate or high social isolation based on their assessed sociability and behaviours that indicated they felt threatened. Researchers similarly took urine and blood samples from these animals examining stress hormones, white blood cells and gene expression. 

What were the basic results?

The researchers found people with perceived social isolation had an average 6.5% increase in the activity of genes making up the CTRA profile. After additional adjustment for stress, depression and level of social support, isolation was associated with a 12.2% increase in the activity of CTRA genes. Social isolation was also associated with increased levels of white blood cells involved in the inflammatory response.

Similar results were found in macaques – those perceived as socially isolated demonstrated higher CTRA gene activity, with up-regulation of "pro-inflammatory" genes and down-regulation of genes involved in the production of antiviral immune proteins.

This was also demonstrated as an impaired response when the macaques were experimentally infected with simian immunodeficiency virus (SIV), a type of virus that affects primates.

Both humans and macaques with perceived social isolation also demonstrated increased urinary levels of the hormone noradrenaline. 

How did the researchers interpret the results?

The researchers concluded that their study shows socially isolated people have elevated sympathetic nervous system activity, which is associated with activation of the CTRA gene profile.

This is characterised by up-regulation of pro-inflammatory genes and down-regulation of genes involved in the production of antiviral proteins.  


People who are lonely and socially isolated have often been suggested as being at higher risk of illness, disease and early death. This study has aimed to further explore the possible biological mechanisms behind this.

The findings suggest it may involve the "fight or flight" response overstimulating the development of inflammatory white blood cells in the bone marrow, while decreasing the production of antiviral proteins. The idea is this altered immune and inflammatory response could therefore contribute to the increased disease risk.

But this is only a hypothesis. Though the research in animals has suggested socially isolated macaques may be more susceptible to viral infection, this study has not proved that socially isolated humans are more likely to become ill or die earlier.

It also does not confirm this is the only biological mechanism by which social isolation may confer an increased disease risk in humans. Feelings of loneliness and social isolation can be complex emotions that may be influenced by many personal, health and life circumstances.

For example, a person may have a chronic disease that has caused them to become more withdrawn, depressed and socially isolated. This chronic disease may then cause an increased mortality risk, rather than being a direct effect of the social isolation.

As such, there may be several contributing factors involved in a cycle and it can be difficult to pin down a single causative factor – isolation, for example – directly leading to the outcome, such as disease or early death.

However, what is fairly apparent from this and previous research is that, whatever the biological mechanism(s) that may be behind it, loneliness and social isolation do seem to be associated in some way with disease and illness.

If you are feeling isolated and lonely, there are a range of organisations that can help you reconnect with peopleVolunteer work can also be an effective way of meeting new people, as well as boosting your self-esteem and wellbeing.

Read more about how to combat feelings of loneliness.

Links To The Headlines

Loneliness is twice as bad as obesity for killing us early: Being isolated suppresses your immune system and knocks years off your life. Daily Mail, November 23 2015

Loneliness triggers biological changes which cause illness and early death. The Daily Telegraph, November 23 2015

Scientists reveal why being lonely increases your chances of dying early. Daily Mirror, November 23 2015

Lonely people's white blood cells less suited to fighting infection, study says. The Independent, November 23 2015

Death by loneliness: Isolation cutting short lives of millions. Daily Express, November 23 2015

Links To Science

Cole SW, Capitanio JP, Chun K, et al. Myeloid differentiation architecture of leukocyte transcriptome dynamics in perceived social isolation. PNAS. Published online November 23 2015

Categories: News