Health

Early detection is key to premature birth numbers rise

Mother gazing at premature baby
Image caption Around 50,000 babies are born prematurely each year in the UK

Despite all the medical advances which have been developed to enable babies to be born safely, early delivery is still a major problem.

Experts agree that the total number of babies being born early is not going down and that the cost to society is huge.

Babies born before 37 weeks of gestation account for around 8% of births in the UK.

Premature birth is the single biggest killer of babies under one year old, and babies born early can often spend months in special care or go on to develop life-long health conditions.

Finding treatments to help prevent premature birth could improve the life chances of the nearly 50,000 babies born early in the UK each year.

But many just do not survive.

Louise's first baby Louis lived for just two days. He was born at 24 weeks, weighing 1lb 12oz. There was little they could do for him when he was born.

"I constantly thought I was going to miscarry, because I was bleeding a lot. But this might have been a sign of infection, which could have affected him too."

Less than a year later, Louise gave birth to Lydia who was born 11 days early. She says it was all thanks to the vigilance of doctors at the 20-week scan.

"They could see that I was dilating already and needed to get an internal scan. But doctors are not normally looking for that sort of thing unless you've got a history of a premature birth."

Louise, who lives in Leicestershire, had a stitch in her cervix two days later followed by regular scans and swabs during the remainder of her pregnancy to check for further problems.

She is now the proud mother of three healthy daughters - Lydia, Jodie and Cara - who were all born by caesarean section, weighing around 8lbs, all with the aid of a stitch to prevent premature arrival.

"If it wasn't for the premature baby clinic at the Leicester Royal Infirmary, Lydia wouldn't be here now."

Premature birth occurs for a number of reasons, including the placenta not functioning properly, a weak cervix which starts to open too early and cysts or fibroids in the womb, which leave the baby short of space.

Infections, blood-related conditions and diabetes and pre-eclampsia can also bring about premature birth.

A history of premature birth and being pregnant with twins or triplets can also increase the risk.

Detecting which women are going to deliver early is crucial in reversing the trend of increasing premature births.

Around two-thirds of premature births are spontaneous, typically with the mother going into labour before the baby is due.

Sophisticated tests

Andrew Shennan, professor of obstetrics at St Thomas' Hospital and consultant obstetrician to baby charity Tommy's, says there has been a major change in this area in the last decade.

"Before, we waited for women to go into labour then we tried to firefight, which was very unsatisfactory. Now we use a number of tests to target our efforts on those in high-risk groups."

The two most important tests involve measuring the length of the cervix with a scan and taking a swab of the vagina to pick up any foetal substances leaking out.

These tests are increasing in their sophistication and can now be combined to get a much more precise idea of the women at risk, says Professor Shennan.

Potassium channels

Research carried out by Dr Rachel Tribe and her team of researchers at King's College London has centred on why the uterus begins contracting too early.

Image caption Around eight per cent of babies in the UK are born before 37 weeks.

They have identified a new way of suppressing uterine muscle contractions - which can cause labour to start early - using a drug already developed for pain and epilepsy.

The drug opened specific potassium channels in cells which control the activity of the muscles of the uterus, forcing them to relax rather than contract.

These potassium channels are thought to be crucial in ensuring that the uterus contracts properly and at the right time.

"This is a significant step forward in the search for future treatments for preterm labour," says Dr Tribe. "But the drug has to be safe to be given in pregnancy so more lab experiments are needed first."

While women with a history of premature birth or other pregnancy complications will automatically be branded 'high risk', many other women will have no way of knowing if they are at risk or not.

'Early markers'

At present there is no accurate screening test available to identify women at risk.

"We are at a loss to help first-time mums at the moment. We are trying to pinpoint a marker to flag up risk, then these women could be filtered into specialist clinics," said Dr Tribe.

Her team is looking particularly at markers of early inflammation, which is known to be a trigger for premature birth.

"Women may not be aware they have this problem because it's asymptomatic," she said.

Scientists from the US and Finland recently published research showing the discovery of a gene linked to premature births.

Their study, in PLoS Genetics, found a strong association to pre-term births in variants of the FSHR - or follicle stimulating hormone receptor - gene.

The researchers said their findings could eventually lead to a test for women at risk of a pre-term birth.

More on this story

Around the BBC

Related Internet links

The BBC is not responsible for the content of external Internet sites