Labor and Birth · Physiologic Birth
Martin RW et al., 1990 · Obstet Gynecol
The relative contribution of uterine activity obtained by home monitoring with a guard ring tocodynamometer compared with seven specific signs and symptoms reported during patient/nurse contact as an aid in detecting preterm labor has not been studied. In this prospective, multicenter study, patients at risk for developing early labor who were randomized to receive home uterine activity monitoring and perinatal nursing support were assessed. The initiator of provider contact (uterine activity detected on routine transmission, patient-perceived signs and symptoms of preterm labor during perinatal nurse contact, or both) resulting in a diagnosis of preterm labor was recorded. Contraction data were then analyzed for an association with preterm labor. There was a strong association of increased uterine activity (four or more contractions per hour) on a repeat monitoring strip with preterm labor (P less than .001). Among patients diagnosed with preterm labor, 31% had increased uterine activity detected on a routine transmission without patient-reported signs and symptoms, compared with 24% who were diagnosed as the result of patient-reported symptoms without increased uterine activity. Daily objective uterine activity data alone have greater incremental value over and above other signs and symptoms as an aid to the physician in diagnosing preterm labor.
Labor and Birth · Physiologic Birth
Katz M et al., 1986 · Obstet Gynecol
Effective tocolytic therapy depends on the ability to make an early diagnosis of preterm labor. This study was designed to assess whether daily ambulatory home monitoring of uterine activity could facilitate early diagnosis of preterm labor. Of 76 patients at high risk for preterm labor who used daily ambulatory tocodynamometry, approximately half developed preterm labor. Evaluation when the diagnosis of preterm labor was first established has shown that in 8% of the patients the cervix was dilated more than 2 cm, shortened to less than 0.5 cm in 23%, and the fetal membranes were intact in all subjects. The same evaluation in 76 nonrandom contemporary controls matched for risk factors, maternal age, and parity has shown that more than 50% had a cervix dilated more than 2 cm, 38% had a cervix shorter than 0.5 cm, and 24% had rupture of the fetal membranes. Ultimately, 88% of the monitored patients and 59% of controls delivered at term. Comparisons between these groups indicate that intermittent home tocodynamometry may indeed be useful in making the early diagnosis of preterm labor.
Labor and Birth · Physiologic Birth
Nageotte MP et al., 1988 · Am J Obstet Gynecol
To assess uterine activity before labor in patients delivering preterm, at term, and postterm, the maximum spontaneous contraction frequency per 10-minute window during the initial portion of antepartum fetal heart rate monitoring was analyzed. Patients with multiple gestation, third trimester bleeding, polyhydramnios, or premature rupture of membranes and those already diagnosed with preterm labor were eliminated from the study. Of the 2446 remaining patients (7247 antepartum fetal heart rate tests) who went into spontaneous labor, 237 did so before 37 completed weeks of gestation, 1077 entered labor at term (38 to 42 completed weeks), and 1132 did so after 42 weeks. There was a significant increase in maximum uterine activity per 10-minute window from 30 to 44 weeks of gestation (average 4.7% per week; r = 0.97, p less than 0.0001). When compared with patients delivering spontaneously at term, average maximum uterine activity per 10-minute window was greatest in the preterm labor group (p less than 0.05) and least in the postterm labor group (p less than 0.05). These differences were present for several weeks preceding the onset of spontaneous labor. All three groups showed a surge of uterine activity during the 3 days before the onset of spontaneous labor.
Evidence Synthesis · Systematic Reviews
Rhoads GG et al., 1991 · Am J Obstet Gynecol
At an interdisciplinary workshop on home monitoring of uterine activity, participants reviewed the basis of this technology and its use in the identification of women at high risk of preterm delivery and in the prevention of preterm birth. Although the guard-ring devices in current use appear capable of detecting uterine activity, they do not clearly distinguish between Braxton Hicks contractions and the contractions of early labor. There was agreement that women destined for preterm delivery have more uterine activity on average than do other women of comparable gestational age but that there is substantial overlap between the two groups. Thus it is uncertain whether this difference can be used effectively for screening purposes. Conferees agreed that there is considerable evidence that twice-daily monitoring of very-high-risk women, in conjunction with daily nursing support and high-quality obstetric care, may prevent preterm births. Available evidence does not clearly distinguish the contribution of tocodynamometry from that of nursing support. A number of areas were identified in which further research is needed.
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