Use of progesterone to treat preterm labour

Premature birth is associated with various medical problems for the newborn including death. The parents can experience emotional turmoil and the economic costs are high for the health systems. Various medications have been used to delay the onset of labour and prevent premature deliveries but with limited success. Some of the drugs have side-effects. Progesterone is a hormone which is known to suppress uterine activity and keep the uterus quiescent until term. Medications which mimic this hormone (progestational agents) were first tried in the late 1950s but interest waned. Recently, new trials studying the use of progestational agents both for prevention as well as treatment of preterm labour have been published. This review of the literature found four trials. We included data from a total of 192 women with threatened or established preterm labour with intact membranes. Two trials compared the use of progestational agents versus placebo in patients concurrently treated with another drug to reduce uterine contractions (tocolytic agent). The other two trials compared the use of progestational agents versus placebo alone. Limited evidence suggests that use of a progesterone, as a co-treatment, may reduce preterm deliveries at less than 37 weeks' gestation. Further larger studies are needed.