Premature birth and induced labour: boosting understanding gives new hope

Around one in 20 pregnancies worldwide ends with the mother going into labour too soon and having her baby prematurely.¹ In contrast, one in every five pregnant women has to have labour induced.² A dire lack of understanding of the natural processes that control labour and childbirth is limiting our ability to help. Professor Andrés López Bernal at the University of Bristol believes boosting understanding could eventually benefit women and their babies.

What is the problem and who does it affect?

Many pregnant women anticipate childbirth with a mixture of excitement and trepidation – hoping for an easy labour and healthy baby. Much attention focuses on the baby’s due date.

If a woman goes into labour too early or too late, her own or her baby’s health can be put at risk. Sadly, it is not always possible to help.

“When a woman goes into labour prematurely, there is little we can do to stop her baby from being born too soon,” says Professor López Bernal. Premature birth can have devastating consequences. Tragically, around 1,500 babies die in the UK each year after being born too soon.^3-5,a,b Many others who survive a very early birth develop lifelong problems such as cerebral palsy, blindness and learning difficulties.

“If a baby is overdue, inducing labour is fraught with potential problems,” continues Professor López Bernal. “The need to use forceps is higher with inductions,⁶ for example, and about 22 per cent of inductions end with an emergency caesarean section.⁷” Labour can be induced for several reasons – if the baby is overdue or isn’t growing properly in the womb, if the mother’s waters have been broken for a while and if the mother has pre-eclampsia

What is the project trying to achieve?

“A remarkable feature of the uterus – the womb – is that it remains relatively relaxed for the nine months of pregnancy, carrying the baby safely, and then, during labour, it contracts forcibly and the baby is born,” explains Professor López Bernal. “The biological processes that control this switch from relaxation to contraction are largely a mystery. We are hoping to boost understanding by studying the role of a naturally occurring hormone called oxytocin.”

Oxytocin is an ancient hormone, which can be traced back through 500 million years of evolution in creatures as diverse as mammals, marsupials and sharks.⁸ It is already used, with varying and unpredictable degrees of success, when attempting to induce labour.

“We are exploring a newly discovered action of oxytocin, which involves turning genes on,” explains Professor López Bernal. “Improving understanding could eventually lead to better control of labour, whether stopping or starting it, with potential health benefits for mother and child.”

What are the researchers’ credentials?

Professor Andres López Bernal, who has been studying childbirth for over 30 years, is an international expert on signalling pathways within the womb. He is collaborating with Professor Craig McArdle, an expert in how oscillating calcium levels within cells can turn on genes, a process that might occur during labour.

References

1. Beck et al. Bull World Health Organ, 2010, 88:31-38
2. NICE guidelines for induction of labour, 2008 http://www.nhs.uk/Planners/pregnancycareplanner/Documents/NICE_induction...
3. Office for National Statistics. Health Statistics Quarterly 35 (Autumn 2007), Table 2.1
4. The Information Centre, Community Health Statistics. NHS Maternity Statistics, England: 2003-04, 2004-05, 2005-06
5. ONS: Health Statistics Quarterly 28 (Winter 2005), 32 (Winter 2006), 36 (Winter 2007)
6. Roberts et al. Paedriatic and Perinatal Epidemiology 2002; 16: 115-123
7. Thorsell et al. Acta Obstet Gynecol Scand 2011; 90: 1094-9
8. Gimpl & Fahrenholz, The Oxytocin Receptor System, Physiological Reviews 2001; 81: 629-683
   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”.