Premature labor, Part I: Risk assessment, etiologic factors, and diagnosis.

BACKGROUND This paper, the first of a two-part series on premature labor, reviews the recent literature on the causes of and risk factors for preterm labor and methods of diagnosis. METHODS A review of the literature on risk determination and diagnosis of preterm labor was conducted by searching MEDLINE files from 1983 to the present, using the key terms "preterm labor," "premature labor," "preterm labor and infection," and "uterine monitoring." Additional references were accessed by cross-referencing the bibliographies of the articles obtained through this search. RESULTS AND CONCLUSIONS Risk factors for preterm labor, which include items related to the pregnant woman's demographic characteristics, history, daily habits, and current pregnancy, have been combined into scoring systems commonly used by clinicians and researchers to single out women at risk for preterm delivery. When such systems are tested in obstetric populations, results show variable success in predicting preterm labor or birth. These inconsistent results could be due, in part, to important factors that have often been omitted from scoring systems, such as chemical abuse, poor nutrition, little social support, demanding work, multiple sexual partners, past or current sexually transmitted diseases, and other gynecologic infections. Women who are considered high risk for preterm labor can benefit from participating in preterm birth prevention programs that incorporate home monitoring, patient education regarding the signs and symptoms of preterm labor, frequent contacts with health professionals, and cervical examinations.