Prematurity prevention: who is at risk?

Previous preterm birth, previous preterm labor, regular uterine activity, uterine distention, and preterm cervical change are factors that are most often present in patients treated for preterm labor or in patients delivered prematurely. In addition to their frequency, their severity is also the highest in terms of patient risk. These factors usually are easily identified, and an appropriate management plan can be implemented to decrease the incidence of preterm births or to at least increase the fetal time in utero. Antenatal bleeding, chronic urinary tract infections, smoking, and maternal age are also associated with preterm labor. Although these factors are not present as often, they have the potential to precipitate preterm labor and preterm delivery. When they are identified, it is necessary to utilize the appropriate therapeutic measures commensurate to the number and/or the degree of the risk factors. Vaginal microbiology, maternal hematocrit, substance abuse, and coitus are factors that are undergoing active investigation in regards to precipitating preterm birth. They are frequently seen in normal pregnancies, but recently have been associated with a greater likelihood for preterm labor and preterm birth. Unequivocal evidence of this association is currently unavailable; however, more and more investigations are reporting a significant association of these factors with preterm births. The relative degree of risk and the optimal management plans for dealing with these factors also await further definition and refinement. We know that there is no surveillance technique, or combination of techniques, that will identify all patients who will eventually deliver preterm. In many reports, despite the diligent attention to many of the earlier-mentioned risk factors, almost two of three patients who have delivered preterm had no easily identified risk factor. In addition, many patients delivered preterm report no perception of uterine activity (Garbaciak JA, Desch C, unpublished data). Other investigators have concluded that because most of the potentially preventable births occur in groups that present with marked cervical dilatation, it may be difficult to lower significantly the preterm birth rate below the current levels. Despite the sometimes dismal outlook regarding the prevention of preterm labor and delivery, the multiple investigators that have reported certain successes in their study populations should give us hope and encourage us to apply those techniques that appear appropriate and effective in our individual populations and patients. We can see and measure successful outcomes only if we are willing to look and aggressively to attempt to decrease untoward perinatal events.(ABSTRACT TRUNCATED AT 400 WORDS)