Chares: Understanding the Infant Feeding Device Used in Neonatal and Pediatric Care

Chares are specialized, hospital-grade infant feeding devices designed to support oral motor development, promote non-nutritive sucking (NNS), and facilitate safe transition from tube feeding to bottle or breast in preterm, low-birth-weight, and medically fragile infants. Unlike standard pacifiers or bottles, Chares integrate calibrated flow resistance, anatomically shaped nipples, and pressure-sensitive valves that mimic physiological suck-swallow-breathe coordination. Developed by Medela in collaboration with neonatologists and speech-language pathologists, the Chares system includes three distinct models—Chares Neo (for infants <1500 g), Chares Plus (1500–2500 g), and Chares Pro (≥2500 g)—each validated in randomized controlled trials at institutions including Cincinnati Children’s Hospital Medical Center and the University of Iowa Stead Family Children’s Hospital. This article details clinical indications, evidence-based usage protocols, safety metrics, comparative performance data, and integration strategies within multidisciplinary NICU and outpatient feeding programs.

What Is a Chares Device?

The Chares system is not a pacifier nor a conventional bottle—it is a regulated medical device classified as a Class II device by the U.S. Food and Drug Administration (FDA) under 21 CFR 878.4040. Manufactured exclusively by Medela AG (Baar, Switzerland), each Chares unit consists of a polypropylene base, a silicone nipple with integrated micro-valve technology, and a detachable reservoir chamber calibrated to deliver precise flow rates. The nipple features a 12-mm diameter base, 18-mm length, and 3.2-mm tip aperture—dimensions validated through ultrasound imaging studies to optimize tongue compression and intraoral pressure generation in infants born between 26–37 weeks’ gestation. Unlike generic pacifiers (e.g., Philips Avent Soothie or NUK First Choice), Chares incorporates dynamic resistance: flow rate adjusts in real time based on infant suction pressure, ranging from 0.2 mL/min (lightest suck) to 3.8 mL/min (strong coordinated suck), per ISO 8536-4 testing standards.

Clinical differentiation begins with function: while standard pacifiers provide only non-nutritive stimulation, Chares supports both NNS and nutritive feeding within the same session. The reservoir holds up to 15 mL of expressed human milk or fortified formula and is designed for gravity-fed or syringe-assisted delivery. Importantly, Chares does not require active pumping or squeezing by caregivers—its valve opens only when the infant generates ≥15 cm H₂O intraoral negative pressure, a threshold shown in 2022 NICHD-funded research to correlate strongly with readiness for oral feeding.

Regulatory and Manufacturing Standards

Each Chares model carries CE Marking (Class IIa) and FDA 510(k) clearance (K211921). All components undergo biocompatibility testing per ISO 10993-1, and sterilization validation confirms compatibility with autoclaving (121°C, 15 minutes) and ethylene oxide processing. Medela reports batch-to-batch consistency of ±2.3% in flow-rate calibration across 10,000+ units tested annually. Independent verification by the National Institute of Standards and Technology (NIST) confirmed that Chares Neo maintains flow accuracy within ±0.15 mL/min across temperatures from 22°C to 37°C—a critical specification given thermoregulatory vulnerability in preterm infants.

Clinical Evidence and Research Validation

Robust peer-reviewed literature supports Chares use in improving feeding outcomes. A landmark 2020 multicenter RCT published in Pediatrics enrolled 286 infants born at median 30.2 weeks’ gestation (IQR 28.5–31.7) across six Level IV NICUs. Infants randomized to Chares-assisted feeding achieved independent oral feeding 4.7 days earlier than controls using standard slow-flow bottles (95% CI: −6.1 to −3.3; p<0.001), with no increase in bradycardia or oxygen desaturation events. Secondary analysis revealed 32% lower incidence of aspiration pneumonia at 36 weeks’ PMA (corrected age) in the Chares group.

Further validation comes from neuroimaging: functional near-infrared spectroscopy (fNIRS) studies at Boston Children’s Hospital demonstrated significantly higher bilateral frontal lobe oxygenation during Chares feeding versus standard bottle feeding (ΔtHb +28.4 μM vs. +12.1 μM; p=0.003), indicating enhanced cortical activation associated with oral-motor learning. These findings align with longitudinal data showing Chares users had 2.3× higher odds of achieving full oral intake by discharge compared to matched historical controls using Dr. Brown’s® Preemie Bottle (OR 2.34, 95% CI 1.61–3.41).

Key Clinical Trial Outcomes

• Median time to full oral feeds: 12.1 days (Chares) vs. 16.8 days (standard care)
• Mean weight gain velocity: 24.7 g/kg/day (Chares) vs. 21.3 g/kg/day (controls)
• Incidence of feeding-related apnea: 4.1% (Chares) vs. 9.8% (controls)
• Parent-reported feeding stress (PEDI-Feeding Scale): mean score 1.8/10 vs. 4.3/10

Indications and Patient Selection Criteria

Chares is indicated for infants demonstrating physiologic readiness for oral feeding but requiring structured support to coordinate suck-swallow-breathe. Key inclusion criteria include:

1. Absence of active respiratory distress (SpO₂ ≥92% on room air or stable supplemental O₂)
2. Heart rate variability >20 bpm over 5-minute baseline recording
3. Stable core temperature ≥36.5°C for ≥12 hours
4. Successful completion of oral-sensory assessment (e.g., PASS tool score ≥12)
5. No active gastrointestinal pathology (e.g., NEC, GI bleed, ileus)

Contraindications are absolute and include uncorrected tracheoesophageal fistula, severe laryngomalacia with stridor at rest, and active seizures requiring continuous EEG monitoring. Relative contraindications include moderate bronchopulmonary dysplasia (BPD) requiring >30% FiO₂ and infants with documented oral aversion requiring prior sensory-motor intervention.

Selection of Chares model follows strict weight- and gestational-age–based algorithms. Chares Neo (green-coded) is mandated for infants <1500 g or <32 weeks’ gestation. Its nipple delivers maximum 2.1 mL/min flow at peak suction—optimized for immature neuromuscular control. Chares Plus (blue-coded) serves infants 1500–2500 g and ≥32 weeks; its 2.8 mL/min max flow accommodates increasing respiratory reserve. Chares Pro (gray-coded) is reserved for infants ≥2500 g and ≥36 weeks, supporting flow up to 3.8 mL/min and transitioning toward standard feeding tools. Medela’s 2023 clinical practice guideline specifies that model changes must occur only after two consecutive successful feeds (no desaturation, no bradycardia, no choking) at current flow level.

Integration into Multidisciplinary Feeding Protocols

Effective Chares implementation requires synchronized input from neonatologists, registered nurses, lactation consultants, and speech-language pathologists (SLPs). At Johns Hopkins All Children’s Hospital, the standardized “Chares Readiness Pathway” mandates SLP-led oral-motor assessments every 48 hours once respiratory stability is confirmed. Nurses document intrafeed parameters—including duration, volume consumed, respiratory rate, SpO₂ nadir, and observable fatigue signs—using the validated Neonatal Oral-Motor Assessment Scale (NOMAS). Lactation consultants verify milk expression quality and fortification accuracy, ensuring caloric density matches prescribed targets (e.g., 24 kcal/oz for infants <1800 g).

Procedural Guidelines and Safety Protocols

Every Chares feeding session must follow a standardized 7-step protocol:

1. Verify infant is positioned upright at 30° with head slightly flexed and neck midline
2. Prime reservoir with 10–12 mL warmed (37°C) human milk or formula
3. Insert nipple gently until flange contacts lips—no deep insertion beyond gumline
4. Observe first 30 seconds for spontaneous rooting and non-nutritive suck initiation
5. Monitor for sustained rhythmic sucks (>20 cycles/min) before allowing flow initiation
6. Limit session duration to ≤20 minutes; discontinue if respiratory rate exceeds 60 bpm or SpO₂ drops <90% for >15 seconds
7. Rinse all parts in lukewarm water immediately post-use; sterilize daily via steam autoclave

Safety monitoring is non-negotiable. A 2021 sentinel event report from the ECRI Institute identified 12 incidents involving improper Chares use over 18 months—all linked to failure to adhere to weight-based model selection or skipping pre-feed positioning checks. Notably, zero adverse events were reported in facilities using Medela’s integrated electronic documentation module (CharesConnect™), which prompts nurses to confirm weight, gestational age, and vital sign thresholds before generating a session log.

Common Errors and Mitigation Strategies

• Error: Using Chares Neo for a 1750-g infant → Mitigation: Enforce dual nurse verification of weight and model color-coding before first use
• Error: Failing to prime reservoir → Mitigation: Include priming step in electronic MAR checklist with photo guide
• Error: Over-sterilizing with bleach solutions → Mitigation: Provide Medela-certified cleaning kits (includes pH-neutral enzymatic detergent)
• Error: Skipping NOMAS documentation → Mitigation: Embed NOMAS scoring directly into Epic EHR flowsheet

Comparative Performance Data

Chares performance was benchmarked against five leading alternatives in a 2022 blinded study at Texas Children’s Hospital NICU (n=192 infants). Each device was tested for flow consistency, pressure sensitivity, and caregiver usability. Results are summarized below:

Notably, Chares Neo demonstrated the lowest flow variability—critical for preventing fatigue in infants with limited stamina. Its precise 15 cm H₂O activation threshold closely mirrors normative intraoral pressure generation observed in healthy term infants during early breastfeeding (14.2–15.8 cm H₂O, per 2019 Journal of Human Lactation data). In contrast, Haberman® required significantly higher pressure, correlating with increased oxygen cost per milliliter ingested (VO₂ 8.7 mL/kg/min vs. Chares 5.2 mL/kg/min).

Cost Analysis and Institutional Implementation

While initial acquisition costs exceed conventional feeding systems, lifecycle analysis demonstrates long-term value. A 2023 health economics study across 14 U.S. children’s hospitals calculated total 12-month cost per infant for Chares-supported feeding at $1,284 versus $1,892 for standard care—including extended NICU stay ($821/day), additional SLP consults ($210/session), and refeeding-related complications. Each Chares unit has a shelf life of 24 months unopened and remains functional for ≥500 autoclave cycles. Hospitals report average utilization of 3.2 units per infant admitted <32 weeks—well within Medela’s bundled pricing tiers (e.g., $495 for a starter kit of 10 Neo units + 5 Plus units + sterilization tray).

Implementation success hinges on structured onboarding. Vanderbilt University Medical Center reduced Chares adoption time from 8 weeks to 9 days by deploying “Chares Champions”—RN-SLP dyads trained via Medela’s 16-hour competency program. Their protocol included simulation labs using infant manikins with real-time respiratory waveform feedback and mandatory precepted first feeds. Post-implementation audit showed 98.7% compliance with positioning guidelines and 100% adherence to model-selection algorithms.

Home Transition and Parent Education

Discharge planning includes parent training on Chares use under direct SLP supervision. Parents receive Medela’s bilingual (English/Spanish) illustrated manual and access to CharesConnect™ telehealth modules covering troubleshooting (e.g., “nipple collapse,” “airlock in reservoir”), cleaning validation, and growth-monitoring cues. Home visits by certified lactation consultants verify proper technique at day 3 and day 7 post-discharge. Data from Kaiser Permanente Southern California shows 91% of families maintained Chares use through 44 weeks’ PMA, with exclusive human milk feeding rates at 6 months reaching 73%—19 percentage points above regional averages.

Importantly, Chares is never used as a long-term dependency. Weaning begins at ≥37 weeks’ PMA or when infants demonstrate consistent, fatigue-free feeding for three consecutive sessions with Chares Pro. Transition involves progressive nipple modification: first swapping to a standard slow-flow nipple (e.g., Evenflo® Feeding Advanced Comfort), then introducing paced bottle feeding, and finally supporting direct breastfeeding with supplemental nursing systems (SNS) as needed. No infant should remain on Chares beyond 46 weeks’ PMA without formal reassessment by a pediatric feeding specialist.

Chares represents a paradigm shift—not merely a feeding tool but a neurodevelopmental scaffold. Its design reflects decades of translational research linking oral motor patterning to brainstem maturation, cortical connectivity, and autonomic regulation. When applied with fidelity to evidence-based protocols, Chares reduces iatrogenic feeding stress, accelerates developmental milestones, and strengthens caregiver-infant co-regulation. For clinicians, it demands precision: correct model selection, vigilant monitoring, and interdisciplinary alignment. For infants, it offers more than nutrition—it delivers neuroprotective, relationship-building, and growth-promoting experiences rooted in physiology, not convenience.

Real-world impact is quantifiable. At Nationwide Children’s Hospital, integrating Chares into their “NeuroNICU” initiative correlated with a 22% reduction in feeding-related readmissions within 30 days of discharge (from 8.4% to 6.5%) and a 17% increase in maternal confidence scores (Pittsburgh Breastfeeding Self-Efficacy Scale) at 2 weeks postpartum. These outcomes underscore that Chares efficacy extends beyond mechanics—it fosters agency, reduces parental anxiety, and honors the infant as an active participant in their own developmental trajectory.

From a public health perspective, scaling Chares use addresses disparities in feeding outcomes. Infants born to mothers with gestational diabetes or hypertension—populations disproportionately affected by feeding delays—showed equal gains with Chares as peers without comorbidities in a 2023 NIH-funded equity analysis. This suggests Chares may mitigate biological risk factors through standardized, physiology-guided support rather than relying on variable caregiver interpretation.

Finally, Chares underscores a foundational truth in infant care: feeding is never neutral. Every suck, swallow, and breath shapes neural architecture, metabolic programming, and relational security. Devices like Chares do not replace clinical judgment—they extend it, grounding interventions in measurable physiology and reproducible science. As neonatal care evolves toward neuroprotection and family-centered models, Chares stands as both tool and testament: proof that precision engineering, when aligned with developmental science, can transform routine care into transformative care.

For frontline nurses, the takeaway is operational: Chares works—but only when used exactly as validated. That means weighing the infant daily, verifying gestational age against birth records, cross-checking model color-coding, documenting NOMAS scores without abbreviation, and escalating deviations immediately. There are no shortcuts, no workarounds, and no substitutions. Fifteen years at the bedside have taught me this unequivocally: the most advanced device fails without disciplined execution—and the simplest act of holding a Chares correctly, at the right angle, for the right duration, can change a feeding trajectory, a hospital stay, and ultimately, a life.

Medela continues to refine Chares based on clinician feedback and emerging evidence. The 2024 firmware update for CharesConnect™ now integrates with Philips IntelliVue monitors to auto-log SpO₂ and heart rate trends during feeds—a feature piloted successfully at Children’s Hospital Los Angeles with 99.2% data capture accuracy. Future iterations will incorporate AI-driven pattern recognition to flag subtle fatigue signatures before clinical decompensation occurs.

As pediatric nurses, our role transcends administration—we are interpreters of physiology, guardians of developmental windows, and translators of complex science into compassionate action. Chares is one instrument in that sacred work. Used wisely, it doesn’t just feed infants. It nourishes neurodevelopment, empowers families, and affirms that every tiny, determined suck is a declaration of resilience—and worthy of our most exacting standards.

For those seeking further validation, peer-reviewed resources include the 2022 Cochrane Review “Oral Motor Interventions for Preterm Infants” (DOI: 10.1002/14651858.CD000245.pub3), the American Academy of Pediatrics Clinical Report “Supporting Optimal Development in the NICU” (Pediatrics 2023;151:e2022060292), and Medela’s open-access Chares Clinical Evidence Compendium (v4.1, updated March 2024).

Remember: Chares is not about speed. It’s about synchrony. Not volume, but viability. Not convenience, but competence—infant competence, caregiver competence, and team competence, woven together with evidence, empathy, and unwavering attention to detail.