Premature contraction of the uterus is one of the major causes of pre-term labour. In the UK, 2-4% of all babies (up to 26,000 per year) are born very prematurely before 32 weeks of pregnancy, and these babies account for 75% of all admissions to intensive neonatal care units. Currently, doctors are unable to delay uterine contractions with massive health consequences. This is because pre-term babies suffer from a high rate of mortality, and those babies that manage to survive have an increased incidence of severe disability. In addition, these circumstances contribute to huge emotional, social and economic costs.Sometimes during normal labour, contraction of the uterus can block the blood vessels within it. This results in a reduction in the supply of oxygen to the uterus and probably has a detrimental affect on its ability to contract. It is also likely that oxygen by-products (called ROS) can cause the same effects. Little is known about the effect that ROS has on the function of the uterus. These researchers will therefore examine the effects that oxygen by-products have on the uterus, with a view to understanding pre-term and full term labour. Ultimately, this may lead to the development of better treatments for the management of labour.