Threatened Preterm LaborASTOS2NCT05343806
Nifedipine Versus Magnesium Sulfate for Late Preterm Tocolysis
A study testing Nifedipine 20 Mg and Magnesium Sulfate in people with Threatened Preterm Labor, run by Assiut University at 1 site in Egypt.
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… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Threatened Preterm Labor
- What is being tested?
- Nifedipine 20 Mg and Magnesium Sulfate
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 264 participants
- Where
- 1 siteEgypt
- Study dates
- 13 Apr 2023to 1 Sep 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Pregnant women with threatened preterm labor defined as 3 or more uterine contractions in 30 minutes confirmed by cardiotocography.
- Gestational age from 32 week + 0 days to (inclusive) 36 weeks + 0 days.
- Women with singleton or multiple pregnancy.
- Women with preterm prelabor rupture of membranes (PROM) will be included if they have uterine contractions.
Who cannot join
- Contraindications for the use of either drugs, such as cardiac disease, hypotension, myasthenia gravis, or renal impairment.
- Contraindications for tocolysis, such as intrauterine demise, intrauterine infection, fetal distress, placental separation, or severe pre-eclampsia.
- Cervical dilatation > 5 cm.
- Cervical length > 30 mm by trans-vaginal ultrasound.
- Cervical cerclage.
Trial locations and contacts
1 site in 1 country.
Egypt1 site
Faculty of Medicine, Assiut University
Asyut, Asyut Governorate, 71515
About this study
Official title: Nifedipine Versus Magnesium Sulfate for Tocolysis in Pregnant Women at 32 - 36 Weeks Gestation With Threatened Preterm Labor
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.
Read more
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.
- Conditions
- Threatened Preterm Labor
- Being tested
- Nifedipine 20 Mg, Magnesium Sulfate
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Nifedipine 20 MgDrug
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 SulfateDrug
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.
| Study group | Role | What they receive |
|---|---|---|
| Nifedipine | Active comparator | 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. Receives: Drug: Nifedipine 20 Mg |
| Magnesium Sulfate | Active comparator | 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. Receives: Drug: Magnesium Sulfate |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 48 hours
Secondary outcomes (10)
Perinatal mortality
Death of the offspring during treatment, labor or neonatal period
Measured: From starting treatment until 1 month of delivery
A composite of adverse neonatal outcomes
convulsions, apnoea, asphyxia, proven meningitis, pneumothorax or sepsis
Measured: within 1 month of delivery
days on ventilation support
number of days on mechanical ventilation
Measured: within 1 month of delivery
length of admission in neonatal intensive care
Number of days in the NICU
Measured: within 1 month of delivery
Prolongation of pregnancy more than 7 days
Number of women not delivering after at least 7 days from starting the intervention
Measured: 7 days after initiation of therapy
Delivery after 37 weeks of gestation
number of women delivered after 37 weeks of gestation
Measured: after 37th week of gestation
Number of days till delivery
Measured: from starting the intervention until delivery
Maternal mortality rate
Number of maternal deaths during pregnancy, labor or puerperium
Measured: from starting treatment until 1 month after delivery
Maternal infection rate
Number of women having Chorioamnionitis, Puerperal sepsis, endometritis, or sepsis
Measured: from starting treatment until 1 month after delivery
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
Measured: from starting treatment until 1 month after delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Apr 2022
- Study start13 Apr 2023
- Primary completion6 Jul 2025
- Study completion1 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Threatened Preterm LaborStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 264 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Karim Abdallah, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05343806
- Sponsor's protocol ID
- ASsiut TOcolytic Study 2
- Acronym
- ASTOS2
- Status last verified
- Apr 2026
- First submitted
- 19 Apr 2022
- Last updated
- 22 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 22 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Nifedipine Versus Magnesium Sulfate for Tocolysis in Pregnant Women at 32 - 36 Weeks Gestation With Threatened Preterm Labor
- ClinicalTrials.gov ID
- NCT05343806
- Acronym / sponsor ID
- ASTOS2 / ASsiut TOcolytic Study 2
- Conditions
- Threatened Preterm Labor
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 264 participants (actual)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- 13 Apr 2023 (actual)
- Primary completion
- 6 Jul 2025 (actual)
- Study completion
- 1 Sep 2025 (actual)
- First posted
- 25 Apr 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Nifedipine | Active comparator | Drug: Nifedipine 20 MgThe 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 | Active comparator | Drug: Magnesium SulfateWomen 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Pregnant women with threatened preterm labor defined as 3 or more uterine contractions in 30 minutes confirmed by cardiotocography.
- Gestational age from 32 week + 0 days to (inclusive) 36 weeks + 0 days.
- Women with singleton or multiple pregnancy.
- Women with preterm prelabor rupture of membranes (PROM) will be included if they have uterine contractions.
Key exclusion criteria (5 listed)
- Contraindications for the use of either drugs, such as cardiac disease, hypotension, myasthenia gravis, or renal impairment.
- Contraindications for tocolysis, such as intrauterine demise, intrauterine infection, fetal distress, placental separation, or severe pre-eclampsia.
- Cervical dilatation > 5 cm.
- Cervical length > 30 mm by trans-vaginal ultrasound.
- Cervical cerclage.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Nifedipine 20 MgThe 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. | Drug | Nifedipine |
| Magnesium SulfateWomen 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. | Drug | Magnesium Sulfate |
Primary outcome
Number of women not delivered within 48 hours of starting tocolytic therapy.
Time frame: 48 hours
postponing delivery for at least 48 hours to allow the time for corticosteroid administration for fatal lung maturity
10 secondary outcomes
Perinatal mortality
Time frame: From starting treatment until 1 month of delivery
A composite of adverse neonatal outcomes
Time frame: within 1 month of delivery
days on ventilation support
Time frame: within 1 month of delivery
length of admission in neonatal intensive care
Time frame: within 1 month of delivery
Prolongation of pregnancy more than 7 days
Time frame: 7 days after initiation of therapy
Delivery after 37 weeks of gestation
Time frame: after 37th week of gestation
Number of days till delivery
Time frame: from starting the intervention until delivery
Maternal mortality rate
Time frame: from starting treatment until 1 month after delivery
Maternal infection rate
Time frame: from starting treatment until 1 month after delivery
Harm to mother from interventions (side effects)
Time frame: from starting treatment until 1 month after delivery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Apr 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Nifedipine 20 Mg and Magnesium Sulfate in people with Threatened Preterm Labor, run by Assiut University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of women not delivered within 48 hours of starting tocolytic therapy. (time frame: 48 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Apr 2026.