Premature birth and brain damage – inflammation may play a role

One of the reasons for premature birth could be inflammation in the amniotic fluid or the placenta caused by bacteria. The infection triggers labour far earlier than expected.

The study saw researchers looking at various factors linked to inflammation, known as markers, in the amniotic fluid of 83 women whose waters broke early or who went into labour prematurely, and of 15 women who had elective caesareans at full term.

“We found that the galectin-3 marker was much higher in women who were threatening preterm delivery and who had signs of infection in their amniotic fluid or placenta,” says Christina Doverhag, a postgraduate student at the Department of Physiology at the Sahlgrenska Academy. “This hasn't been measured in the amniotic fluid before.”

The researchers also wanted to investigate the role of free radicals in brain injury in children who were born prematurely or who suffered a lack of oxygen during birth. Free radicals damage the body's cells and are formed during inflammation, among other things.

“We studied two inflammation markers – galectin-3 and the enzyme NADPH-oxidase – in newborn mice. Our animal studies showed that galectin-3 can exacerbate brain injury, particularly in newborn males. In our other animal study we removed the NADPH-oxidase enzyme, and this led to greater injury and inflammation in some of the mice,” says Doverhag, who draws the conclusion that both inflammation and galectin-3 play a significant role in brain damage in newborn children.

This means that some medicines under development for the treatment of stroke and brain injury in adults, and which work in part by blocking the release of free radicals and NADPH-oxidase, are unlikely to be suitable for newborns with the same symptoms. They could, in fact, result in further injury.

“On the other hand, there is a common substance that can block galectin-3 and which is about to undergo further testing in the hunt for a treatment for brain injury in newborns,” says Doverhag. “That substance is lactose, also known as milk sugar.”

However, further research is needed before concrete treatments become available.
“We need to know more about the content of the amniotic fluid and how it affects premature birth, and about how the sex of the unborn baby affects the amniotic fluid,” says Doverhag.
PREMATURE BABIES
Babies born before the 37th week of pregnancy are classified as premature. Between five and six per cent of babies born each year fall into this category. There are many reasons for premature birth, including maternal illness and early breaking of the waters. Children who are born prematurely are more likely to suffer with illnesses or complications as their organs have not yet matured.

The thesis has been successfully defended.

For more information, please contact:
Christina Doverhag, postgraduate student at the Perinatal Center at the Institute of Neuroscience and Physiology, tel: +46 31 786 3393, mobile: +46 73 201 2625, e-mail: Christina.doverhag@fysiologi.gu.se
Doctoral thesis for the degree of PhD (Medicine) at the Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy

Title of thesis: Inflammation in experimental neonatal brain injury and in a clinical study of preterm birth; Involvement of galectin-3 and free radical formation

Journal: Environmental Science and Technology.
Title of article: Therapeutic levels of levonorgestrel detected in blood plasma of fish: results from screening rainbow trout exposed to treated sewage effluents.

Authors: Jerker Fick, Richard H Lindberg, Jari Parkkonen, Björn Arvidsson, Mats Tysklind, D G Joakim Larsson