Amnioinfusion's Protective Effects on Respiratory and Longitudinal Pediatric Outcomes After Intrapartum Thick Meconium Exposure

Summary

Thick meconium in the amniotic fluid occurs in about one out of seven pregnancies and increases the chance that a newborn may have breathing problems after birth. These problems can include the need for oxygen, breathing support, admission to the neonatal intensive care unit (NICU), or, in severe cases, meconium aspiration syndrome or persistent pulmonary hypertension.

Although amnioinfusion or placing sterile fluid into the uterus during labor was previously studied as a way to reduce these complications, earlier research had major limitations. Past studies included all types of meconium, used different fluid types and temperatures, had inconsistent protocols, and did not measure biomarkers of inflammation or look at long-term outcomes. As a result, it is still unclear whether a modern, standardized approach to amnioinfusion can meaningfully improve newborn health when the meconium is truly thick.

The PEARL Trial is a randomized clinical trial designed to answer this question. The study will enroll pregnant individuals at or beyond 36 weeks of gestation who develop thick meconium-stained amniotic fluid, confirmed using a simple, objective measurement ("meconium-crit"). Participants will be randomly assigned to receive either:

Warm lactated Ringer's (LR) amnioinfusion through an intrauterine pressure catheter (IUPC), following a standardized protocol, or standard care without amnioinfusion.

The main goal is to determine whether warm LR amnioinfusion reduces short-term breathing problems in newborns. The study also collects umbilical cord blood at birth to evaluate markers of inflammation and potential brain injury, which may help explain why some infants develop complications. Families will also be contacted when their child is 12 months old to complete a developmental questionnaire that is widely used in pediatric practice.

By using a clear definition of thick meconium, a warm LR infusion protocol, fidelity checklists, and long-term follow-up, this trial aims to provide high-quality evidence to guide care in labor and delivery units nationwide.

Conditions

• Cord Blood
• Neonatal Respiratory Distress Related Conditions
• Meconium
• Perinatal Morbidity
• Neonatal Acidosis
• Neonatal Brain Injury
• Maternal Morbidity
• Mechanical Ventilation
• CPAP
• Surfactant
• Perinatal Death
• Amnioinfusion
• NICU Admission

Interventions

DEVICE

Intrauterine pressure catheter

Standardized warm amnioinfusion consisting of a 500 mL bolus of warmed (37°C) lactated ringer's infused over 30 minutes through an intrauterine pressure catheter (IUPC), followed by a continuous maintenance infusion of 125 mL/hour until the amniotic fluid clears or delivery.

OTHER

Standard obstetric care at discretion of delivery provider

Route obstetric care at discretion of delivery provider

Sponsors & Collaborators

• The Gerber Foundation

  collaborator OTHER

• Medical College of Wisconsin

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-05-15

Primary Completion

2029-04-15

Completion

2030-04-15

FDA Device

Yes

Countries

• United States

Study Locations