Nifedipine Versus Magnesium Sulfate for Late Preterm Tocolysis

Threatened Preterm Labor Clinical Trial

— ASTOS2  

Official title:

Nifedipine Versus Magnesium Sulfate for Tocolysis in Pregnant Women at 32 - 36 Weeks Gestation With Threatened Preterm Labor

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05343806
• Other study ID #: ASsiut TOcolytic Study 2
• Status: Recruiting
• Phase: N/A
• Start date: March 1, 2023
• Est. completion date: February 1, 2026

Study information

• Verified date: December 2023
• Source: Assiut University
• Contact: Karim Abdallah, MD
• Phone: +201270595485
• Email: karimsayed88[@]aun.edu.eg
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Objective: This trial is designed to compare between the effectiveness of nifedipine versus magnesium sulfate (MgSO4) for tocolysis in women with threatened preterm labor.

Patient Population: The population will include pregnant women at gestational age between 32 and 36 weeks who are 18 years old or older and have signs of threatened preterm labor.

Study Design: This is a single-center, prospective, randomized controlled clinical trial. A total of 264 women pregnant between 32 and 36 weeks having threatened preterm labor will be enrolled and randomized into two parallel treatment arms. Patients in the group A will receive nifedipine, while patients in group B will MgSO4 only.

Treatment: All patients will be randomized on the day of enrollment. Patients with threatened preterm labor will receive the respective tocolysis in each group. All patients will receive corticosteroids for lung maturity according to the local protocol.

Primary outcome: Number of women not delivered within 48 hours of starting tocolytic therapy.

Secondary outcomes: perinatal mortality, a composite of adverse neonatal outcomes, birth weight, days on ventilation support, length of admission in neonatal intensive care, prolongation of pregnancy more than 7 days, delivery after 37 weeks of gestation, number of days till delivery, maternal mortality, maternal infection, and harm to mother from intervention.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 264
• Est. completion date: February 1, 2026
• Est. primary completion date: November 1, 2025
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

1. Pregnant women with threatened preterm labor defined as 3 or more uterine contractions in 30 minutes confirmed by cardiotocography.

2. Gestational age from 32 week + 0 days to (inclusive) 36 weeks + 0 days.

3. Women with singleton or multiple pregnancy.

4. Women with preterm prelabor rupture of membranes (PROM) will be included if they have uterine contractions.

Exclusion Criteria:

1. Contraindications for the use of either drugs, such as cardiac disease, hypotension, myasthenia gravis, or renal impairment.

2. Contraindications for tocolysis, such as intrauterine demise, intrauterine infection, fetal distress, placental separation, or severe pre-eclampsia.

3. Cervical dilatation > 5 cm.

4. Cervical length > 30 mm by trans-vaginal ultrasound.

5. Cervical cerclage.

Related Conditions & MeSH terms

• Obstetric Labor, Premature
• Premature Birth
• Threatened Preterm Labor

Intervention

Drug:
• Nifedipine 20 Mg
The initial dose of nifedipine will be 2 × 10 mg nifedipine capsules orally in the first hour, followed by 20 mg slow-release nifedipine every 6 hours for the next 47 hours. In the first hour after starting nifedipine, blood pressure and heart rate will be measured every 15 minutes. If blood pressure remains within the normal limits, treatment will be continued.
• Magnesium Sulfate
Women will receive only MgSo4. A loading dose of MgSo4 will be given immediately after enrollment as 4 gm diluted in 200 mL of saline solution administered intravenous over a period of 20 minutes. Afterwards, the maintenance dose of MgSo4 will be administered intravenous in a dose of 1 gm/hour given as 6 gm diluted in 500 mL saline solution titrated with a rate of 100 mL per hour, then this dose is repeated every 6 hours for 48 hours. Respiratory rate and knee jerk will be assessed hourly for women in the MgSo4 group. Serum magnesium level will be measured if clinically indicated.

Locations

Country	Name	City	State
Egypt	Faculty of Medicine, Assiut University	Assiut

Sponsors (1)

Lead Sponsor	Collaborator
Assiut University

Country where clinical trial is conducted

Egypt, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of women not delivered within 48 hours of starting tocolytic therapy.	postponing delivery for at least 48 hours to allow the time for corticosteroid administration for fatal lung maturity	48 hours
Secondary	Perinatal mortality	Death of the offspring during treatment, labor or neonatal period	From starting treatment until 1 month of delivery
Secondary	A composite of adverse neonatal outcomes	convulsions, apnoea, asphyxia, proven meningitis, pneumothorax or sepsis	within 1 month of delivery
Secondary	days on ventilation support	number of days on mechanical ventilation	within 1 month of delivery
Secondary	length of admission in neonatal intensive care	Number of days in the NICU	within 1 month of delivery
Secondary	Prolongation of pregnancy more than 7 days	Number of women not delivering after at least 7 days from starting the intervention	7 days after initiation of therapy
Secondary	Delivery after 37 weeks of gestation	number of women delivered after 37 weeks of gestation	after 37th week of gestation
Secondary	Number of days till delivery		from starting the intervention until delivery
Secondary	Maternal mortality rate	Number of maternal deaths during pregnancy, labor or puerperium	from starting treatment until 1 month after delivery
Secondary	Maternal infection rate	Number of women having Chorioamnionitis, Puerperal sepsis, endometritis, or sepsis	from starting treatment until 1 month after delivery
Secondary	Harm to mother from interventions (side effects)	admission to intensive care, anaphylactic shock, dyspnoea, hypotension (leading to cardiotocography abnormalities), liver test abnormalities (elevated aspartate aminotransferase (AST) or alanine aminotransferase (ALT)), general side effects (nausea, vomiting, headache) and postpartum haemorrhage defined as >500 mL blood loss	from starting treatment until 1 month after delivery