Intravaginal Magnesium Sulfate vs Intravenous Dexamethasone for Labor Acceleration: A Bayesian Adaptive Randomized Controlled Trial

Investigating the effect of vaginal magnesium sulfate on labor progress compared to intravenous dexamethasone in primiparous pregnant women

A randomized, adaptive, parallel-group, phase 3 clinical trial with three arms (magnesium sulfate vaginal, intravenous dexamethasone, and routine care control), blinded outcome assessment, and interim analysis. The trial will enroll 150 patients initially, with potential sample size adjustment via Bayesian simulation. Randomization will use block allocation (block sizes of 3, 6, 12) generated via sealedenvelope.com, with allocation concealment maintained through sequentially numbered opaque envelopes.

Maternity ward of Kamali Hospital

Inclusion criteria: Pregnant woman candidate for vaginal birth, primigravida gestational age>= 38 weeks; Non-inclusion criteria: Indications for cesarean section including failure to progress, cessation of labor, decreased heart rate, bleeding and cleft palate, placenta abruption, fever, and chorioamnionitis, underlying diseases such as diabetes and hypertension, Preeclampsia and eclampsia

Intervention group: receiving 10 cc of magnesium sulfate 50% topically on the cervix once in the latent phase and once in the active phase of labor. - Comparison group 50 people in the comparison group will be given 2 cc (8 grams) of intravenous dexamethasone

Duration of labor, changes in Bishop's score and reduction of labor pain Reduce bleeding

Request to Change Study Type in the IRCT System Respectfully, we request a modification of the study type from "Traditional Randomized Clinical Trial" to "Adaptive Clinical Trial (Bayesian Approach)" in the IRCT system. The key changes are as follows: Key Modifications: Study Type: Revised to: "A three-arm Bayesian adaptive clinical trial, including an interim analysis after collecting data from 50 patients in each group. If equivalence or superiority of magnesium sulfate (posterior probability ≥85%) is confirmed, the dexamethasone arm will be discontinued, and allocation will continue between the magnesium sulfate and control groups." Data Analysis Method: Revised to: "Bayesian analysis using non-informative prior distributions, calculation of the probability of superiority, and reporting results with a Bayesian credible interval." Ethical Considerations: Added: Revised informed consent to inform patients about the possible discontinuation of the dexamethasone arm. Establishment of an independent Data and Safety Monitoring Board (DSMB) for safety oversight and interim analysis. Scientific and Ethical Justifications for the Changes: Limited Evidence: No direct comparison between magnesium sulfate and dexamethasone exists in previous studies. Resource Optimization: Preventing sample wastage by discontinuing the non-optimal arm (dexamethasone) if magnesium sulfate proves superior. Safety Considerations: Reducing patient exposure to dexamethasone side effects (e.g., increased blood pressure, immune suppression).

After the eligibility of the patient was recognized and written informed consent was obtained, the patients were randomly assigned to one of the three intervention (magnesium sulfate) and comparison (intravenous dexamethasone) and control ( routine treatment) will be allocated. A randomization list is prepared. To prepare the randomization list, from the web-based software to the address https://www.sealedenvelope.com/simple-randomiser/v1/lists will be used.

It is not possible to blind the patient. The researcher investigating the outcome and analyzing the data: He is not aware of the patient's randomization group and he is the only researcher who randomly selected the list. He is aware of this matter