Labour is the onset of regular contractions combined with the cervix (neck of the womb) opening. Preterm labour is when labour starts before 37 weeks gestation. Some women will go into labour for no apparent reason, some will have ruptured their membranes (see below) or may have infection. Some will have a weak cervix and some will have twins or triplets (see twins & more). Of course some women will be delivered early, either by Caesarean section of induction of labour, because there are problems with the pregnancy and it is safest to end the pregnancy sooner rather than later. About 5 – 10% of women will have their babies early, for one reason or another.
The reason we are concerned about preterm delivery is because of the risk to the baby of being born early.
In general, the earlier you are born, the greater risk of early death or handicap (figure1). Early deliveries account for about 75% of all perinatal deaths (around the time of childbirth). If you have abdominal pain or believe you are contracting, even if you are not due, you should seek medical assistance
Early detection and effective management of preterm labour is essential in trying to reduce the incidence and complications associated with preterm birth, which is the leading cause of infant morbidity and mortality and accounts for 35% of all healthcare spending on infants.
Widespread treatment of women with signs and symptoms of preterm labour has failed to stop the increase in the prevalence of preterm births. In the United States 9.4% of births were preterm in 1981; that number increased to 11% in 1993. The aim of using tocolytic drugs and rest are to try and prolong pregnancy to term or long enough for substantial increases in gestational age and infant birth weight or, at a minimum, to prolong gestation while an effective regimen of corticosteroids can be administered to enhance fetal lung development. The value of these medications is tempered by uncertainty as to whether pregnancy prolongation will improve infant outcomes. Biomarkers such as fetal fibronectin (fFN) and transvaginal ultrasound have been used as tests to predict preterm delivery risk.