Professor Andrew Shennan says certain bacteria, infections or a damaged cervix may cause premature birth, but it's often unclear why babies arrive early
Q: My first baby was born extremely premature, and although I'd like to have another baby I'm scared of giving birth early again. Is there any way of telling if that's likely to happen, or anything that can be done to stop it?
A: Professor Andrew Shennan, head of the baby charity Tommy's (tommys.org) preterm birth surveillance clinic, says: "Around 60,000 babies are born premature in the UK each year, but it's not often clear why, making it hard for doctors to predict and prevent.
"We're researching the causes of premature birth so we can find ways to stop it happening, and our latest study found levels of bacteria and chemicals in the womb seem to play a role. It's early science but eventually we hope these could be measured as warning signs and even adjusted with treatment.
"In the meantime, we already know several things make premature birth more likely, so mums and care teams can take steps to guard against it.
"Some risk factors can't be controlled, such as age, race and pregnancy history. Black mothers, under-18s and over-40s are more likely to give birth early. Premature birth is more common with twins, and if it's already happened in a previous pregnancy.
"Infections and operations can damage the cervix (neck of the womb) so it's less able to keep the baby inside. The risk is also raised by long-term health conditions like diabetes and autoimmune disorders, or pregnancy complications like pre-eclampsia and cholestasis.
"When things like this mean a mum might give birth early, we can do tests to see how likely that is. In Tommy's preterm birth clinic, we use our QUIPP app which is very precise; the wider NHS has other tests, like measuring the cervix and swabbing the vagina for a protein called fetal fibronectin.
"It's very important to keep up with antenatal appointments, so the care team can spot any problems early, when treatment is most effective. We can prevent premature birth with hormone therapies like progesterone or specialist operations like a cervical stitch.
"Eating a balanced diet and staying active during pregnancy can help lower the chances of premature birth. Women who have a very low or high BMI when they get pregnant are more likely to give birth early, so it's important to be as healthy as possible.
"Premature birth has been linked to gum disease, so take extra care of your teeth, avoiding fizzy drinks and sugary foods. Avoiding alcohol, cigarettes and recreational drugs also reduces the risks.
"Research suggests premature birth may be linked to clinical stress or depression, so mental health is as important as physical.
"Giving birth early can fuel anxiety and complex emotions – care teams know this and will be ready to support you, not judge you. Raise any concerns with your midwife or doctor, trust your instincts if something doesn't feel right, and ask to see someone else if you don't feel listened to."