ABSTRACT
A preterm birth is one that occurs between fetal viability and 37 completed weeks of gestation. Delivery of a previable conceptus represents a spontaneous abortion rather than a preterm birth. The latter is particularly important because if rupture of membranes is present, the management and prognosis are different from those of patients with preterm labor and intact membranes. Amniocentesis is easy to perform in patients with preterm labor and intact membranes. Patients with preterm labor with intact membranes and documented intra-amniotic infection/inflammation are unlikely to respond to tocolysis and are at risk of developing pulmonary edema if attempts are made to delay delivery with tocolysis. The observations, and the lack of efficacy of adjuvant antibiotics in the prevention of preterm delivery and neonatal morbidity, suggest that antibiotics should be used in patients with preterm labor and intact membranes. The shorter the sonographic cervical length in the midtrimester, the higher the risk of spontaneous preterm labor/delivery.
