Blueprints Obstetrics and Gynecology, Sixth Edition

Chapter

Complications of Labor and Delivery

PRETERM LABOR

Labor that occurs before week thirty-seven is called preterm labor. Many patients present with preterm contractions, but only those who have cervical change as measured on cervical examination are diagnosed as having preterm labor. It differs from cervical insufficiency, which is a silent, painless dilation, and effacement of the cervix. Both can result in preterm delivery, which is the leading cause of fetal morbidity and mortality in the United States. The incidence of preterm delivery in the United States reached a peak in two thousand five to more than twelve percent of all births, which is higher than that in two thousand where the rate was eleven point six percent. Although since two thousand six the preterm birth rate has declined, it is still higher than that in two thousand. Approximately a half of a million babies are born preterm each year, though only approximately eighty thousand of these are before thirty-two weeks' gestation.