Intrapartum Sildenafil in Laboring Mothers (PRISM)

Sildenafil Citrate to Improve Maternal and Neonatal Outcomes in Low-Resource Settings: A Randomized Pilot Feasibility Trial: Pilot Randomized Intrapartum Sildenafil in Mothers

The goal of this feasibility pilot clinical trial is to learn if sildenafil citrate 50mg orally, up to three times during labor, can be appropriately administered, with limited clinical side effects, to laboring mothers to determine feasibility across a spectrum of available healthcare resources.

The main questions it aims to answer are:

• What are the fetal heart rate monitoring practices in a low-resource setting?
• What are the indications for operative delivery in a low-resource?
• What is the rate of relevant primary and secondary outcomes to possibly target in a large RCT of intrapartum sildenafil?
• What is the limited effect size of sildenafil citrate on maternal and neonatal outcomes in a low-resource setting?

Researchers will compare the administration of sildenafil citrate 50 mg orally to a placebo (a look-alike substance that contains no drug) to see if procedures are feasible, the drug is tolerated, the target outcomes are achievable, and effect size is as expected.

Participants will:

• Take Sildenafil 50 mg/placebo every eight hours or a placebo every eight hours for up to 24 hours during labor
• Have the (mothers & babies) medical charts reviewed for outcomes, including fetal distress, operative delivery, maternal side effects, neonatal bag & mask ventilation, Apgar scores, and seizures.
• Have a neonatal neurological assessment prior to discharge
• Have phone call assessments for re-hospitalization or mortality 7 days post-delivery
• Receive child development assessments at 1 year, 2 years and 3 years of age by the Ages and Stages Questionnaire administered via a telephone call

The results of this feasibility pilot trial will be used to inform the design and conduct of a large pragmatic randomized controlled trial to determine if sildenafil citrate, compared to placebo, will decrease fetal distress and perinatal asphyxia.

Study Overview

• Status: Withdrawn
• Conditions: Development, Infant; Neonatal Asphyxia; Intrapartum Fetal Distress; Intrapartum Asphyxia
• Intervention / Treatment: Drug: Sildenafil 50 mg Oral Tablet; Drug: Placebo Oral Tablet

Detailed Description

After informed consent obtained, mother will be randomized, using computer-generated stratified randomization codes by the pharmacy. Clinicians, researcher, and primary caregivers will be masked. Subjects will be randomly assigned to either the treatment arm or the placebo concurrent control.

Eligible women who consent for the study will be randomized to receive sildenafil 50 mg orally every 8 hours up to a total of 3 doses or to receive the placebo every 8 hours up to a total of 3 does during the course of labor. Neither medication no placebo will be given following completion of labor. All additional care of the mother and infant will be provided according to the local standard of care. Outcomes will be collected following delivery, discharge, and 7-days post-partum. 7-day follow-up for outcomes will be obtained per a telephone call. One, two, and three year infant developmental and behavior outcome will be assessed using the Ages and Stages Questionnaire.

• Study Type: Interventional
• Phase: Phase 3

Contacts and Locations

Study Locations

• Cameroon
  • Douala, Cameroon
    • Cameroon Baptist Convention Health Services
• Kenya
  • Nakuru, Kenya
    • Egerton University/Nakuru County Referral Hospital
• Zambia
  • Lusaka, Zambia
    • University Teaching Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Pregnant women presenting in early labor with a term pregnancy (≥ 37 weeks gestation)

   • Early labor will be defined as cervical dilation less than or equal to 6 cm
   • Gestational age will be calculated from the most reliable variable using the following hierarchy of reliability: 2) gestational dating ultrasound completed at any time during the pregnancy (with preference to the earliest exam); 2) date of last menstrual period if menses are regular.
2. Planned vaginal delivery and admission to health facility with clear plan for spontaneous or induced vaginal delivery
3. Maternal age ≥ 18yrs or minors 14-17yrs eligible in countries where married or pregnant minors or their authorized representatives are legally permitted to give consent
4. A single, live fetus in cephalic presentation confirmed prior to randomization

Exclusion Criteria:

1. Unknown gestational age
2. Maternal history of cesarean delivery
3. Advanced stage of labor (>6 cm or 10 cm cervical dilation per local standards) and pushing, or too distressed to understand, confirm, or give informed consent regardless of cervical dilation
4. Not capable of giving consent due to other health problems, such as obstetric emergencies (i.e. antepartum hemorrhage) or mental disorder
5. Maternal contraindication to sildenafil therapy, such as hypersensitivity to nitrates or nitrites
6. Any medical condition considered a contraindication per the judgement of site investigators
7. Recognized fetal anomaly
8. Any maternal medical condition or status that precludes informed consent
9. Non-emancipated minors (as per local regulations
10. Plan for cesarean delivery prior to enrollment
11. Previous randomization in the trial

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Oral Sildenafil 50mg; Sildenafil citrate 50mg given orally every eight hours up to 3 doses while mother is in labor	Drug: Sildenafil 50 mg Oral Tablet; Sildenafil 50 mg given orally every eight hours up to three times while mother is in labor; Other Names: Revatio; Sildenafil
Placebo Comparator: Placebo; Identical-appearing treatment that does not contain the test drug given orally every eight hours up to 3 doses while mother is in labor	Drug: Placebo Oral Tablet; Placebo table given orally every eight hours up to three times while mother is in labor

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of perinatal mortality	Documentation of stillbirth or neonatal death	96 hours after enrollment
Percentage of operative delivery	Documentation of type of delivery	96 hours after enrollment
Indication for operative delivery	Documentation of type of delivery	96 hours after enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of mothers who received fetal heart rate monitoring	Documentation of rate of heart rate monitoring	96 hours after enrollment
Indication for fetal heart rate monitoring	Documentation of the indication for use of fetal heart rate monitoring	96 hours after enrollment
Apgar Score	Documentation of Apgar score at 1 minute and 5 minutes (Value 0-10, with 10 meaning better outcome)	1 minute and 5 minutes after birth
Percentage of use of bag and mask ventilation in neonates	Documentation of the use of bag and mask ventilation as resuscitation after delivery	20 minutes after delivery
Percentage of neonates with neonatal encephalopathy	Documentation of neonatal neurological exam determined by "modified Sarnat Score (no, mild, moderate, and severe)" ; higher score indicates more severe encephalopathy	24 hours after birth
Percentage of neonates with neonatal encephalopathy	Documentation of neonatal neurological exam determined by "Thompson Score (no, mild, moderate and severe)"; higher score indicates more severe encephalopathy	24 hours after birth
Percentage of neonates with hypoxemia	Documentation of saturations < 95% measured by noninvasive pre/post pulse oximetry	48 hours after birth or at discharge, if early discharge
Percentage of infants with neonatal hypoxic-ischemic encephalopathy	Documentation of neonatal encephalopathy	96 hours after enrollment
Percentage of neonatal ICU admissions	Documentation of admission to the Neonatal Intensive Care Unit or comparable level of care	96 hours after enrollment
Percentage of maternal rehospitalization	Maternal rehospitalization after initial discharge from the hospital assessed by telephone call to mother	7 days
Percentage of neonatal rehospitalization	Neonatal rehospitalization after initial discharge from the hospital assessed by telephone call to mother	7 days
Infant/child developmental assessment	Score on "Ages and Stages Questionnaire" obtained by telephone call to parent (developmental assessment tool which scores items (Yes=10, Sometimes=5, Not Yet=0) in areas of Communication, Gross Motor, Fine Motor, Problem Solving, and Personal-Social. Scoring of items are totaled and placed on a graph indicating cutoff score. If score is above cutoff, the child's development appears to be on schedule; near the cutoff, may provide learning activities and monitor; and below cutoff, requiring further assessment. 12-month cutoffs (Communication 15.64; Gross Motor 21.49; Fine Motor 34.50; Problem Solving 27.32 and Personal-Social 21.73); 24-month cutoffs ((Communication 25.17; Gross Motor 38.07; Fine Motor 35.16; Problem Solving 29.78 and Personal-Social 31.54); and 36-month cutoffs (Communication 30.99; Gross Motor 36.99; Fine Motor 18.07; Problem Solving 30.29 and Personal-Social 35.33)	12 months, 24 months, 36 months

Collaborators and Investigators

• Sponsor: University of Alabama at Birmingham
• Collaborators: University Teaching Hospital, Lusaka, Zambia; Cameroon Baptist Convention Health; Egerton University
• Investigators: Principal Investigator: Waldemar A Carlo, MD, University of Alabama at Birmingham

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2025
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): September 30, 2028

Study Registration Dates

• First Submitted: April 12, 2024
• First Submitted That Met QC Criteria: April 16, 2024
• First Posted (Actual): April 22, 2024

Study Record Updates

• Last Update Posted (Estimated): September 16, 2025
• Last Update Submitted That Met QC Criteria: September 9, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Keywords: Sildenafil citrate
• Additional Relevant MeSH Terms: Infant, Newborn, Diseases; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Asphyxia Neonatorum; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Substandard Drugs; Pharmaceutical Preparations; Dosage Forms; Amides; Purines; Sulfonamides; Sulfones; Piperazines; Sildenafil Citrate; Counterfeit Drugs; Tablets
• Other Study ID Numbers: UAB-300010901; UAB Dixon Endowed Ch/3102800 (Other Grant/Funding Number: UAB Dixon Endowed Chair)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No