Premature birth: what links bacterial infection with early births?
This research was completed on 31 December 2013
Published on 7 June 2011
Each week in the UK, more than 25 babies die after being born prematurely.1-3,a,b Many who survive a very early birth develop lifelong disabilities. Researchers think that some women might go into labour early because changes in their immune system during pregnancy might increase their vulnerability to infection. They are investigating this possibility, with the longer-term aim of finding ways to identify women who are at risk of premature labour and stop their babies from being born too soon.
- What's the problem and who does it affect?
- What is the project trying to achieve?
- What are the researchers' credentials?
- Who stands to benefit from this research and how?
What's the problem and who does it affect?
Early births put babies in danger
Over 60,000 babies are born prematurely in the UK every year.4-7,c Tragically, around 1,500 of them die.1-3,a,b Premature birth is in fact the biggest killer of babies in the UK.1-3,a,b
Very premature babies who do survive can spend many weeks in hospital in intensive care. Sadly, they are at risk of developing lifelong disabilities, such as cerebral palsy, blindness, hearing loss and learning difficulties. The babies’ families can be profoundly affected by the stress of caring for them.
Around 40 per cent of premature births happen because the mother goes into labour too soon, often without warning – many parents are totally unprepared for the early arrival of their baby.8 Other premature births happen after the mothers’ waters break early or by planned caesarean sections, prompted by complications in the pregnancy.
Once a woman has gone into the final stages of early labour, it is not normally possible to stop her baby from being born too soon. Little is known about why some women go into labour prematurely and it is not always possible to identify those who are at risk.
What is the project trying to achieve?
What causes premature labour?
The researchers aim to boost our understanding of why some women go into labour too soon. They are investigating possible links between early labour and changes in the mother’s immune response to infection.
The immune system normally attacks and destroys dangerous bacteria that enter the body. During pregnancy, subtle changes occur – the immune system is slightly suppressed, which helps stop it from attacking the baby.
The researchers think these changes might make some pregnant women more vulnerable to infection, allowing bacteria to grow and spread within the womb. They believe the numbers of bacteria may eventually become so high that a tipping point is reached, prompting a large inflammatory response. Inflammation might then cause the baby to be born early – inflammation is, in fact, known to have a key role in triggering labour.
The researchers are investigating their hypothesis in the laboratory, using samples donated by around 120 pregnant women. The women are all at high risk of going into labour early, because they have already had at least one baby too soon.
What are the researchers' credentials?
|Project Leader||Professor Nigel Klein PhD FRCPCH|
|Location||Department of Infectious Diseases and Microbiology, Institute of Child Health and Department of Obstetrics, Institute for Women's Health, University College London in conjunction with the Department of Obstetrics and Gynaecology, The Rosie Hospital, University of Cambridge|
|Grant awarded||23 November 2010|
|Start date||1 September 2011|
|End date||31 December 2013|
|Grant code||SP4572, GN1791|
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The researchers have broad-ranging expertise – in pregnancy and childbirth, bacteria, the immune response to infection, and the cellular and molecular processes that trigger labour. Combining these strengths is enabling the team to make important progress.
The researchers are building on their successful completion of a preliminary study that suggested many women who go into labour early have high levels of bacterial infection within the womb.
Expertise in cutting-edge laboratory techniques is vital to the researchers’ success. They are experienced in assessing the body’s immune response to infection – on a cellular and molecular level. They are also skilled in using highly sophisticated techniques to detect and identify bacteria, and measure how many are present.
Who stands to benefit from this research and how?
Stopping early births
The researchers aim to help pregnant women who are at risk of going into labour prematurely. At the moment, it is not possible to identify all of these women or stop their babies from being born too soon.
The researchers suspect that some pregnant women might go into labour early because of changes in the way their immune system responds to bacterial infections within the womb. If they are right, this work could ultimately lead to new diagnostic markers, which identify women who are at risk of giving birth early.
The researchers’ work might even guide the development of new treatments that aim to stop babies from being born too soon. For example, treatments that alter the immune response to infection could be beneficial.
Premature birth is a major cause of death and disability in babies.1-3 a,b Economic costs are staggering. Treatments that can stop babies from being born too soon, and spare them from developing life-long disabilities, could bring profound benefits to the babies, their families and society as a whole.
- Office for National Statistics. (2009) Child Mortality Statistics in England and Wales, 2009 (Table 6) [Online]. Available from http://www.statistics.gov.uk/downloads/theme_health/child-mortality/chil... [Accessed 22 March 2011]
- Northern Ireland Registrar. (2009) General Annual Report 2009 (Section 4: Stillbirths and Infant Deaths) [Online]. Available from http://www.nisra.gov.uk/demography/default.asp76.htm [Accessed on 22 March 2011]
- General Register Office for Scotland. (2009) Vital Events Reference Tables 2009 (Section 4: Stillbirths and Infant Deaths) [Online]. Available from http://www.gro-scotland.gov.uk/statistics/theme/vital-events/general/ref... [Accessed on 22 March 2011]
- Office of National Statistics. (2010) Birth Summary Tables, England and Wales 2009: 21/07/10 (Table 1)[Online]. Available from http://www.statistics.gov.uk/statbase/Product.asp?vlnk=14408. [Accessed: 22 March 2011]
- Northern Ireland Registrar General (2009) Annual Report 2009 (Section 3 Births, Table 3) [Online] Available from http://www.nisra.gov.uk/demography/default.asp76.htm [Accessed: 22 March 2011]
- General Register Office for Scotland. (2009) Vital Events Reference Tables 2009 (Section 3 Births; Table 3.1) [Online]. Available from http://www.gro-scotland.gov.uk/statistics/theme/vital-events/general/ref... [Accessed 22 March 2011]
- Office of National Statistics News Release (May 2007). 1 in 13 live births in England and Wales are born preterm. [Online] Available from http://www.statistics.gov.uk/pdfdir/preterm0507.pdf [Accessed 22 March 2011]
Goldenberg RL. The management of preterm labor. Obstet Gynecol 2002; 100:1020-37.
a. For England and Wales, deaths listed as due to “immaturity related conditions”
b. For Scotland and Northern Ireland, deaths listed as due to “disorders related to length of gestation and fetal growth”
c. Calculation made by Action Medical Research based on figures in references 4-7 for the number of births a year in the UK and the number of preterm deliveries in England, respectively. Estimate assumes incidence of premature birth is the same for the UK overall as it is for England.