Risk scoring system and preterm birth
Volume 163 Number 3
10. Goldenberg RL, Davis RO, Cutter GR, Hoffman H, Brumfield CG, Foster JM. Prematurity, post dates, and growth retardation. AMJ OBSTETGYNECOL 1989:160;46270. II. Harrell FE, Lee KL, McKinnis RA. Enhancements in logistic and proportional hazard regression procedures. In: Proceedings of the Sixth Annual SAS Users Group In-
ternational Conference. Cary, North Carolina: SAS Institute Inc. 1981: 116-68. 12. Main DM, Gabbe SG. Risk scoring for preterm labor: where do we go from here? AM J OBSTET GYNECOL 1987;157:789-93. 13. lams JD. Current status of prematurity prevention. JAMA 1989;262:265-6.
A prospective randomized comparison of oral terbutaline and magnesium oxide for the maintenance of tocolysis Louis E. Ridgway III, MD, Kevin Muise, MD, Jeffrey W. Wright, MD, Robert M. Patterson, MD; and Edward R. Newton, MD San Antonio, Texas We compared oral magnesium oxide with oral terbutaline sulfate in a prospective, randomized manner to determine efficacy and side effects. Preterm labor patients whose labor was arrested with parenteral tocolysis were randomized to oral tocolysis with either magnesium oxide, 200 mg every 3 to 4 hours (n = 23), or terbutaline, 2.5 to 5 mg every 3 to 4 hours (n = 27). The number of patients who were delivered of infants before 36 weeks' gestation was similar between groups (18.5% receiving terbutaline versus 17.4% receiving magnesium). At least one side effect occurred in 81.5% of patients in the terbutaline group and 47.8% in the magnesium group (p < 0.01). Finally, the cost for 1 day of magnesium (20 cents) is approximately one third the cost of terbutaline (56 cents). These data suggest that oral magnesium oxide is as effective as terbutaline for the maintenance of tocolysis, with fewer side effects and at a lower cost. (AM J OBSTET GVNECOL 1990;163:879-82.)
Key words: Preterm labor, tocolysis, oral magnesium, oral terbutaline Patients with successfully arrested preterm labor are generally given oral tocolytic medication until pregnancy is judged to be near term. This oral tocolytic therapy is intended to decrease recurrences of preterm labor and increase the chances of term delivery. 13Sympathomimetic agents are currently the agents of choice for this therapy. However, patients treated with oral l3-sympathomimetic agents frequently have unpleasant side effects. Some patients may even discontinue their medication because of the side effects. I. 3 Further, the cost of l3-sympathomimetic agents may be prohibitive for some patients. Recently, oral magnesium has been suggested to From the Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San Antonio. Presented at the Tenth Annual Meeting of the Society of Perinatal Obstetricians, Houston, Texas, January 23-27, 1990. Reprint requests: Louis E. Ridgway, III, MD, Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78284-
7836. 6/6/22319
be an effective and economical alternative to 13sympathomimetic agents. 3•5 However, there have been no prospective; randomized studies that compare the two drugs. We sought to compare, in a prospective randomized fashion, oral magnesium oxide with oral terbutaline sulfate in the maintenance of tocolysis.
Materials and methods The study population consisted of 60 preterm labor patients who had labor successfully arrested with parenteral therapy. The study was approved by the Institutional Review Board at The University of Texas Health Science Center at San Antonio. Informed consent was obtained from all patients before entry to the study. The criteria for diagnosis of pre term labor were: (1) gestational age between 25 and 35 weeks as determined by last menstrual period and real-time ultrasonography; (2) three contractions in 20 minutes that persisted despite intravenous hydration with 500 ml of normal saline solution and prolonged sedation with 8 to 20 mg of morphine sulfate; (3) any cervical change.
879
880 Ridgway et al.
September 1990 Am J Obstet Gynecol
Table I. Patient characteristics
Age (yr) Gravidity (median) Parity (median) Education level (yr) (median) Dilatation (cm) Effacement Station (median) Estimated gestational age on entry (wk)
T erbutaline (n = 27)
Magnesium (n = 23)
P Value
22.9 ± 5.8 2.0 1.0 12
24.1 ± 7.1 2.0 1.0 11
NS NS NS NS
0.5 ± 0.8 20% ± 28 31.3 ± 3.3
0.8 ± 1.2 23% ± 32 -3 31.8 ± 2.1
NS NS NS NS
T erbutaline (n = 27)
Magnesium (n = 23)
P Value
37.9 ± 2.4
38.3 ± 2.3
NS
3028 ± 438 18.5
2954 ± 513 17.4
NS NS
ILl 28.5 ± 23.1 11 56 cents
4.3 26.7 ± 18.5 9 20 cents
NS NS NS
-3
Table II. Pregnancy outcome data
Estimated gestational age at delivery (wk) Birth weight (gm) Before 36 wk estimated gestational age (%) Before 36 wk Dubowitz (%) Days on oral tocolytic agents Discontinued therapy (%) Cost per day
The choice of parenteral tocolytic agent was at the discretion of the resident physician in charge of the patient's care. After achieving uterine quiescence for 12 to 24 hours, the patients were randomized into one of the two oral tocolytic treatment groups. Group I received magnesium oxide, 200 mg orally every 3 to 4 hours. Patients assigned to Group II received 2.5 to 5 mg of terbutaline sulfate orally every 3 to 4 hours. For the first 24 hours of oral therapy, the patients were maintained on strict bed rest. Light ambulation was begun on the second day. If the patient showed no evidence of recurrent preterm labor, she was discharged at 48 to 72 hours. Patients were evaluated for recurrent preterm labor during weekly clinic visits. They were questioned concerning side effects and compliance. Patients were specifically asked about experiencing a "fast heart rate," "feeling your heart beating in your chest," nervousness, shaking, nausea, vomiting, diarrhea, or any other symptoms. If a patient failed to attend clinic, she was contacted at home and information concerning side effects was elicited. The patients were maintained on oral tocolytic agents until 36 completed weeks' gestation. Patients who underwent recurrent preterm labor while taking oral tocolytic agents were restarted on parenteral therapy. If treatment was successful they were placed on the oral tocolytic agent to which they were originally randomized.
Statistical analysis was performed with the X2 test or the Fisher exact test for categoric variables. For continuous variables, the two-tailed Student t test was used and for interval variables the Wilcoxon ranksum test was used. An 0: of
Volume 163 Number 3
10. Goldenberg RL, Davis RO, Cutter GR, Hoffman H, Brumfield CG, Foster JM. Prematurity, post dates, and growth retardation. AMJ OBSTETGYNECOL 1989:160;46270. II. Harrell FE, Lee KL, McKinnis RA. Enhancements in logistic and proportional hazard regression procedures. In: Proceedings of the Sixth Annual SAS Users Group In-
ternational Conference. Cary, North Carolina: SAS Institute Inc. 1981: 116-68. 12. Main DM, Gabbe SG. Risk scoring for preterm labor: where do we go from here? AM J OBSTET GYNECOL 1987;157:789-93. 13. lams JD. Current status of prematurity prevention. JAMA 1989;262:265-6.
A prospective randomized comparison of oral terbutaline and magnesium oxide for the maintenance of tocolysis Louis E. Ridgway III, MD, Kevin Muise, MD, Jeffrey W. Wright, MD, Robert M. Patterson, MD; and Edward R. Newton, MD San Antonio, Texas We compared oral magnesium oxide with oral terbutaline sulfate in a prospective, randomized manner to determine efficacy and side effects. Preterm labor patients whose labor was arrested with parenteral tocolysis were randomized to oral tocolysis with either magnesium oxide, 200 mg every 3 to 4 hours (n = 23), or terbutaline, 2.5 to 5 mg every 3 to 4 hours (n = 27). The number of patients who were delivered of infants before 36 weeks' gestation was similar between groups (18.5% receiving terbutaline versus 17.4% receiving magnesium). At least one side effect occurred in 81.5% of patients in the terbutaline group and 47.8% in the magnesium group (p < 0.01). Finally, the cost for 1 day of magnesium (20 cents) is approximately one third the cost of terbutaline (56 cents). These data suggest that oral magnesium oxide is as effective as terbutaline for the maintenance of tocolysis, with fewer side effects and at a lower cost. (AM J OBSTET GVNECOL 1990;163:879-82.)
Key words: Preterm labor, tocolysis, oral magnesium, oral terbutaline Patients with successfully arrested preterm labor are generally given oral tocolytic medication until pregnancy is judged to be near term. This oral tocolytic therapy is intended to decrease recurrences of preterm labor and increase the chances of term delivery. 13Sympathomimetic agents are currently the agents of choice for this therapy. However, patients treated with oral l3-sympathomimetic agents frequently have unpleasant side effects. Some patients may even discontinue their medication because of the side effects. I. 3 Further, the cost of l3-sympathomimetic agents may be prohibitive for some patients. Recently, oral magnesium has been suggested to From the Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San Antonio. Presented at the Tenth Annual Meeting of the Society of Perinatal Obstetricians, Houston, Texas, January 23-27, 1990. Reprint requests: Louis E. Ridgway, III, MD, Department of Obstetrics and Gynecology, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78284-
7836. 6/6/22319
be an effective and economical alternative to 13sympathomimetic agents. 3•5 However, there have been no prospective; randomized studies that compare the two drugs. We sought to compare, in a prospective randomized fashion, oral magnesium oxide with oral terbutaline sulfate in the maintenance of tocolysis.
Materials and methods The study population consisted of 60 preterm labor patients who had labor successfully arrested with parenteral therapy. The study was approved by the Institutional Review Board at The University of Texas Health Science Center at San Antonio. Informed consent was obtained from all patients before entry to the study. The criteria for diagnosis of pre term labor were: (1) gestational age between 25 and 35 weeks as determined by last menstrual period and real-time ultrasonography; (2) three contractions in 20 minutes that persisted despite intravenous hydration with 500 ml of normal saline solution and prolonged sedation with 8 to 20 mg of morphine sulfate; (3) any cervical change.
879
880 Ridgway et al.
September 1990 Am J Obstet Gynecol
Table I. Patient characteristics
Age (yr) Gravidity (median) Parity (median) Education level (yr) (median) Dilatation (cm) Effacement Station (median) Estimated gestational age on entry (wk)
T erbutaline (n = 27)
Magnesium (n = 23)
P Value
22.9 ± 5.8 2.0 1.0 12
24.1 ± 7.1 2.0 1.0 11
NS NS NS NS
0.5 ± 0.8 20% ± 28 31.3 ± 3.3
0.8 ± 1.2 23% ± 32 -3 31.8 ± 2.1
NS NS NS NS
T erbutaline (n = 27)
Magnesium (n = 23)
P Value
37.9 ± 2.4
38.3 ± 2.3
NS
3028 ± 438 18.5
2954 ± 513 17.4
NS NS
ILl 28.5 ± 23.1 11 56 cents
4.3 26.7 ± 18.5 9 20 cents
NS NS NS
-3
Table II. Pregnancy outcome data
Estimated gestational age at delivery (wk) Birth weight (gm) Before 36 wk estimated gestational age (%) Before 36 wk Dubowitz (%) Days on oral tocolytic agents Discontinued therapy (%) Cost per day
The choice of parenteral tocolytic agent was at the discretion of the resident physician in charge of the patient's care. After achieving uterine quiescence for 12 to 24 hours, the patients were randomized into one of the two oral tocolytic treatment groups. Group I received magnesium oxide, 200 mg orally every 3 to 4 hours. Patients assigned to Group II received 2.5 to 5 mg of terbutaline sulfate orally every 3 to 4 hours. For the first 24 hours of oral therapy, the patients were maintained on strict bed rest. Light ambulation was begun on the second day. If the patient showed no evidence of recurrent preterm labor, she was discharged at 48 to 72 hours. Patients were evaluated for recurrent preterm labor during weekly clinic visits. They were questioned concerning side effects and compliance. Patients were specifically asked about experiencing a "fast heart rate," "feeling your heart beating in your chest," nervousness, shaking, nausea, vomiting, diarrhea, or any other symptoms. If a patient failed to attend clinic, she was contacted at home and information concerning side effects was elicited. The patients were maintained on oral tocolytic agents until 36 completed weeks' gestation. Patients who underwent recurrent preterm labor while taking oral tocolytic agents were restarted on parenteral therapy. If treatment was successful they were placed on the oral tocolytic agent to which they were originally randomized.
Statistical analysis was performed with the X2 test or the Fisher exact test for categoric variables. For continuous variables, the two-tailed Student t test was used and for interval variables the Wilcoxon ranksum test was used. An 0: of
