Trial Outcomes & Findings for Magnesium Sulfate Versus Nifedipine for the Acute Tocolysis of Preterm Labor: A Prospective, Randomized Trial (NCT NCT00185900)

NCT ID: NCT00185900

Last Updated: 2018-11-19

Results Overview

Uterine quiescence defined by 12 hours of six or fewer contractions per hour and no further cervical change within 48 hours of tocolytic initiation.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 192 participants
• Primary outcome timeframe: 48 hours after administration of study medication.
• Results posted on: 2018-11-19

Participant Flow

Participant milestones

Measure	Magnesium Sulfate Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Overall Study STARTED	92	100
Overall Study COMPLETED	92	100
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Magnesium Sulfate Versus Nifedipine for the Acute Tocolysis of Preterm Labor: A Prospective, Randomized Trial

Baseline characteristics by cohort

Measure	Magnesium Sulfate n=92 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.	Total n=192 Participants Total of all reporting groups
Age, Continuous	26.6 years STANDARD_DEVIATION 6.8 • n=5 Participants	26.3 years STANDARD_DEVIATION 6.3 • n=7 Participants	26.5 years STANDARD_DEVIATION 6.6 • n=5 Participants
Sex: Female, Male Female	92 Participants n=5 Participants	100 Participants n=7 Participants	192 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	92 participants n=5 Participants	100 participants n=7 Participants	192 participants n=5 Participants

PRIMARY outcome

Timeframe: 48 hours after administration of study medication.

Uterine quiescence defined by 12 hours of six or fewer contractions per hour and no further cervical change within 48 hours of tocolytic initiation.

Outcome measures

Measure	Magnesium Sulfate n=92 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Number of Participants With Prevention of Preterm Delivery for 48 Hours With Attainment of Uterine Quiescence	80 Participants	72 Participants

SECONDARY outcome

Timeframe: Until delivery, up to 42 weeks of gestation

Uterine quiescence was defined by 12 hours of six of fewer contractions per hour and no further cervical change.

Outcome measures

Measure	Magnesium Sulfate n=92 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Time to Uterine Quiescence	8.4 hours Standard Deviation 6.5	6.1 hours Standard Deviation 6.3

SECONDARY outcome

Timeframe: Until delivery, up to 42 weeks of gestation

Presented as weeks

Outcome measures

Measure	Magnesium Sulfate n=92 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Gestational Age at Delivery	35.8 weeks Standard Deviation 3.4	36.0 weeks Standard Deviation 3.1

SECONDARY outcome

Timeframe: Until delivery, up to 42 weeks of gestation

Population: Data included twins, so the group totals are greater than seen in the Overall Number of Participants Analyzed

Presented as grams

Outcome measures

Measure	Magnesium Sulfate n=106 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=110 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Neonatal Birth Weight	2550 grams Standard Deviation 802	2650 grams Standard Deviation 698

SECONDARY outcome

Timeframe: From study enrollment until discharge from delivery hospital, up to 30 days after delivery.

A composite of any of the following: chest pain, pulmonary edema, shortness of breath or hypotension.

Outcome measures

Measure	Magnesium Sulfate n=92 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Serious Maternal Adverse Effect	20 Participants	10 Participants

SECONDARY outcome

Timeframe: From delivery until discharge from the hospital, up to 30 days of age

Population: Data included twins, so the group totals are greater than seen in the Overall Number of Participants Analyzed.

Defined as any of the following: respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, sepsis or fetal/neonatal death.

Outcome measures

Measure	Magnesium Sulfate n=106 Participants Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=110 Participants Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Composite Neonatal Morbidity	27 Participants	22 Participants

Adverse Events

Magnesium Sulfate

Serious events: 25 serious events

Other events: 29 other events

Deaths: 0 deaths

Nifedipine

Serious events: 12 serious events

Other events: 22 other events

Deaths: 0 deaths

Serious adverse events

Measure	Magnesium Sulfate n=92 participants at risk Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 participants at risk Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Respiratory, thoracic and mediastinal disorders Shortness of breath	14.1% 13/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	5.0% 5/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Respiratory, thoracic and mediastinal disorders Pulmonary edema	3.3% 3/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	0.00% 0/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Vascular disorders Hypotension	2.2% 2/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	3.0% 3/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Cardiac disorders Chest pain	7.6% 7/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	4.0% 4/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.

Other adverse events

Measure	Magnesium Sulfate n=92 participants at risk Preterm labor treatment with Magnesium Sulfate. Magnesium Sulfate: Preterm labor treatment with Magnesium Sulfate 4 gram bolus followed by 2 gm per hour infusion. 2 Gm bolus as needed and/or rate increase up to 4gm per hour were allowed at the discretion of the treating physician.	Nifedipine n=100 participants at risk Preterm labor treatment with Nifedipine. Nifedipine: Preterm labor treatment with Nifedipine 10 mg. sublingually every 20 minutes for three doses, followed by 20 mg. orally every 4 or 6 hours.
Gastrointestinal disorders Nausea	31.5% 29/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	6.0% 6/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Nervous system disorders Lethargy	29.3% 27/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	3.0% 3/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Gastrointestinal disorders Vomiting	26.1% 24/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	5.0% 5/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Skin and subcutaneous tissue disorders Flushing	21.7% 20/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	1.0% 1/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Eye disorders Blurry Vision	13.0% 12/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	0.00% 0/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Nervous system disorders Dizziness	17.4% 16/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	3.0% 3/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Eye disorders Double vision	3.3% 3/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	0.00% 0/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Nervous system disorders Headache	12.0% 11/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	22.0% 22/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Cardiac disorders Palpitations	1.1% 1/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	0.00% 0/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.
Gastrointestinal disorders Heartburn	6.5% 6/92 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.	6.0% 6/100 • From study enrollment until discharge from the delivery hospital, up to 30 days after delivery. Adverse events were assessed by patient interview from a list of adverse effects and chart review.

Additional Information

Dr. Anna Girsen

Stanford University

Phone: (650) 725-5720

Email: agirsen@stanford.edu

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place