In the UK, about 50 pregnant and postnatal women develop life-threatening severe maternal sepsis (infection of the blood or "blood poisoning") for every woman who dies from the condition, according to a study from UK researchers published in PLOS Medicine. The study also suggests that signs of severe sepsis should be regarded as an obstetric emergency, and that doctors should be aware that prescribing antibiotics does not necessarily prevent progression of an infection to severe sepsis.

The authors, led by Professor Marian Knight from the University of Oxford, also found that the onset of severe sepsis is often very rapid, and women who have recently had an infection, such as a urine, genital tract or respiratory infection, are at particularly high risk of developing severe maternal sepsis.

The authors reached these conclusions by examining information from the United Kingdom Obstetric Surveillance System (a system in which obstetricians from all hospitals around the UK send clinical information to a central point) between June 2011 and May 2012.

Over this time period, the authors found that there were 365 cases of maternal sepsis, giving an incidence of severe maternal sepsis of 4.7 women per 10,000. Seventy-one women with severe sepsis (19.5% of cases) developed septic shock, and five women (1.4% of cases) died. The most common source of sepsis (implicated in about a third of cases) was a genital tract infection. The authors also found that having a fever, taking antibiotics in the two weeks preceding sepsis, and all types of operative delivery (including caesarean section) were risk factors for maternal sepsis.

These findings suggest that pregnant or recently pregnant women with an infection need closer attention than women who are not pregnant, and also that adequate follow-up is necessary to ensure eradication of the infection.

The authors say: "This study emphasizes that both primary and secondary care practitioners should remain aware that pregnant or recently pregnant women with suspected infection need closer attention than women who are not pregnant."

They continue: "Antibiotic prescription does not necessarily prevent progression to severe sepsis, and women should be followed up to ensure recovery.

Professor Knight adds: "Women should be aware that if their symptoms persist they should seek further advice from their doctor or midwife."