Call to tackle maternal blood infection risk

“Pregnant women and new mothers need closer attention for signs of potentially fatal sepsis, a study says,” reports BBC News.

While still rare, sepsis – a blood infection – is now the leading cause of maternal death in the UK.

Sepsis can potentially be very serious, as it can cause a rapid fall in blood pressure (septic shock), which can lead to multiple organ failure. If untreated, sepsis can be fatal.

The study collected information on all cases of severe sepsis that were treated in hospital maternity units from June 2011 to May 2012.

It found there were 365 confirmed cases of severe sepsis out of over 780,000 maternities. Out of these, five women died (meaning around 0.05% of maternities were affected).

The most common place for the infection to have spread to the blood from was the urinary and genital tract. Severe sepsis occurred rapidly, often within 24 hours of the first symptoms. Over 40% of women with severe sepsis had an illness with a high temperature, or were taking antibiotics in the previous two weeks.

This study highlights the importance of identifying infections in pregnant women and women who have recently given birth, especially in the first few days after delivery. During these periods, if you have a high temperature over 38°C or are on antibiotics but not getting better, you should seek medical attention.

Where did the story come from?

The study was carried out by researchers from the University of Oxford, Northwick Park Hospital, Bradford Royal Infirmary and St Michael’s Hospital in Bristol. It was funded by the National Institute for Health Research.

The study was published in the peer-reviewed, open-access medical journal PLOS Medicine, so the study can be read online for free.

BBC News reported the study accurately and provided sage advice from one of the authors, Professor Knight, who said that, “women who are pregnant or have recently given birth need to be aware that if they are not getting better after being prescribed antibiotics – for example, if they continue to have high fevers, extreme shivering or pain – they should get further advice from their doctor or midwife urgently”.

What kind of research was this?

This was a case-control study. The researchers studied all women in the UK diagnosed with severe sepsis (blood poisoning) during pregnancy or during the six weeks after delivery in all maternity units in the UK, from June 1 2011 to May 31 2012 (“cases”), as well as two unaffected (“control”) women per case.

Sepsis is the leading cause of maternal death in the UK, with a rate of 1.13 per 100,000 maternities between 2006 and 2008. The aim of this study was to identify risk factors, the sources of infection and type of organisms responsible, in order to improve prevention and management strategies.

A case-control study selects people with a condition, and matches each of them to at least one other person without the condition; this can be done by factors such as age and sex. In this study, controls were women who did not have severe sepsis, and delivered immediately before each case in the same hospital. Medical histories and exposures can then be compared between the cases and controls to look for associations, and thus risk factors, for the condition. This type of study is useful in investigating rare and emergency conditions, but cannot prove causation.

What did the research involve?

The researchers collected information from all 214 hospitals in the UK that have maternity units led by obstetricians. This included all cases of sepsis around pregnancy and two controls for each case. They compared the sociodemographic, medical history and delivery characteristics between the cases and controls. They also compared the cases that developed into septic shock with those that didn’t, to identify factors that were associated with increased severity.

What were the basic results?

In terms of severe sepsis cases:

There were 365 confirmed cases out of 780,537 maternities.
For most women, it was less than 24 hours between the first sign of systemic inflammatory response syndrome (SIRS) and the diagnosis of severe sepsis (SIRS is a term used to describe cases where two or more symptoms associated with sepsis are present).
134 occurred during pregnancy and 231 were after delivery.
Those cases that occurred after delivery happened, on average, after three days.
114 women were admitted to the intensive care unit (ICU).
29 (8%) women had a miscarriage or a termination of pregnancy.
Five infants were stillborn and seven died in the neonatal period.

In terms of septic shock cases:

71 (20%) of the women developed septic shock.
Five women died.

In terms of sources of infection:

A source was identified in 270 cases (70%).
Genital tract infection was responsible for 20.2% of cases during pregnancy and 37.2% of cases after delivery.
Urinary tract infection caused 33.6% of cases during pregnancy and 11.7% of cases after delivery.
Wound infection caused 14.3% of cases after delivery.
Respiratory tract infection caused 9% of cases during pregnancy and 3.5% of cases after delivery.

In terms of organisms responsible:

E. coli was the most common organism, occurring in 21.1% of infections.
Group A streptococcus was the next most common organism, occurring in 8.8% of infections; for most women with group A streptococcal infection, there was less than nine hours between the first sign of SIRS and severe sepsis, with half having less than two hours between the first signs and diagnosis.
50% of women with group A streptococcal infection progressed to septic shock.

Risk factors for severe sepsis included women who:

were of black or other minority ethnic origin
were primiparous (giving birth for the first time)
had a pre-existing medical problem
had a febrile (high temperature) illness or were taking antibiotics in the two weeks before developing severe sepsis

All types of deliveries requiring operations were risk factors for severe sepsis. These were:

operative vaginal delivery
pre-labour caesarean section
caesarean section after the onset of labour

Risk factors for developing septic shock were:

multiple pregnancy
group A streptococcus

How did the researchers interpret the results?

The researchers concluded that “over 40% of women with severe sepsis had a febrile illness or were taking antibiotics prior to presentation, which suggests that at least a proportion were not adequately diagnosed, treated or followed up … it cannot be assumed that antibiotics will prevent progression to severe sepsis … there is a need to ensure that follow-up happens to ensure that treatment is effective”. They also recommend that “signs of severe sepsis in peripartum women, particularly with confirmed or suspected group A streptococcal infection, should be regarded as an obstetric emergency”.

Conclusion

This comprehensive study highlights several areas where awareness of the risks of sepsis in pregnancy should be increased in both primary and secondary care. These include:

If there is clinical suspicion of infection with group A streptococcus, then urgent action should be taken.
There should be increased care given to pregnant women and women who have just given birth who have a suspected infection.
High-dose intravenous antibiotics should be given within one hour of admission for suspected sepsis.
Vigilant infection control measures should be employed during vaginal delivery.
Despite antibiotics being routinely prescribed before planned caesarean sections, women are still at risk of severe sepsis and need to be closely monitored.
There should be consideration for clinicians to give prophylactic antibiotics before operative vaginal deliveries.
There should be consideration for clinicians to give prophylactic antibiotics at the time the decision is made to perform an emergency caesarean section.

Strengths of the study include its size and the 100% participation rate of maternity units in the UK, which should account for any regional or socioeconomic differences.

If you are pregnant or have just given birth, and have signs or symptoms of infection, such as a high temperature of over 38°C, it is important to seek medical advice immediately.