And we still don't know in many cases why labour starts early or how to stop it. Illness in the mother, such as diabetes, high blood pressure or heart disease. Fetal abnormalities or death. Premature labour can develop in any woman but especially very young, single or unsupported mothers, and those who are underweight or smoke. For example there is growing evidence that stress, particularly when sudden or severe, can induce labour.
Infection is another potential trigger.
Vaginal infections such as Gonorrhoea, Chlamydia, Trichomonas, and Group B Streptococci have all been linked to preterm labour. A condition called bacterial vaginosis, which changes the acidity of the vagina, is also associated with preterm labour, possibly because it reduces the body's natural defences against infection. It may therefore, be possible to reduce the risk by screening for and treating these infections with antibiotics. But this must be done before premature labour starts. Once labour begins it is too late.