Monitoring Uterine Activity in Women at Risk for Preterm Labor

ABSTRACT & COMMENTARY

Synopsis: For all pregnancies at risk for preterm labor, women who have daily contact with a nurse, with or without the use of a home uterine activity monitor, have no better pregnancy outcomes when compared with a program of education, daily uterine palpation by the patient, and weekly contact with a nurse.

Source: Dyson DC, et al. N Engl J Med 1998;338:15-19.

To determine whether the rate of preterm birth could be reduced by home monitoring of uterine activity or frequent contact between nurses and pregnant patients at risk for preterm delivery, Dyson and colleagues randomly assigned 2422 pregnant women with known risk factors for preterm labor. The group (844 were with twins) was assigned to receive education about the signs and symptoms of preterm labor and how to perform palpation to detect uterine contractions and one of the three following interventions: a weekly telephone call from a nurse to review their daily log of uterine activity and emphasize the importance of the patient's assessment of symptoms and palpation of uterine activity; a daily telephone call from a nurse stressing these same points; or daily contact with a nurse as well as use of a home uterine activity monitor for one hour each morning and evening with transmission of that data after each monitoring session.

Women who did not use a home uterine activity monitor were told to call their obstetrician or labor and delivery unit if contractions for singleton pregnancies exceeded four or more per hour, and six or more per hour for twins. Women using a home uterine activity monitor were called if their contraction activity exceeded the accepted threshold, and they were also told to call immediately if they had symptoms of preterm labor or increased uterine activity. Those providing health care for the women in the study did not know to which group the patients had been assigned.

No significant difference was noted in the incidence of preterm birth less than 35 weeks gestation, the primary end point for the study, in any of the patient groups. Similarly, no difference was noted in cervical dilatation at the time the patient presented in preterm labor or for neonatal outcomes such as birthweight, admission to the neonatal intensive care unit, or ventilatory therapy. Women in the home-monitoring group did make significantly more unscheduled visits to their obstetrician than women in the daily or weekly contact groups.

Dyson et al conclude that, for both singleton and twin pregnancies at risk for preterm labor, women who have daily contact with a nurse (with or without the use of a home uterine activity monitor) have no better pregnancy outcomes when compared with a program of education, daily uterine palpation by the patient, and weekly contact with a nurse.

COMMENT BY STEVEN G. GABBE, MD

For more than a decade, obstetricians and gynecologists have sought to reduce the rate of preterm birth through the use of daily home uterine activity monitoring and nursing contact. The cost-effectiveness of this approach has been repeatedly questioned. In a carefully performed prospective, randomized study, Dyson et al clearly demonstrate that home uterine activity monitoring, coupled with daily nursing contact, is no better than weekly nursing contact in motivated patients who have undergone a well-designed program of education. In my mind, the important message from this study is not that technology has failed but that teaching patients about the signs and symptoms of preterm labor, such as an increase in vaginal discharge, cramping, and backache, and instructing them in self-palpation of uterine activity to be performed twice each day for one hour can identify women at risk for preterm labor at relatively low cost. That this approach worked just as well in patients with twin gestations is an extremely important observation.