Assessing the Effect of Infant-directed Unidirectional Feeding Valves on Milk Volume Intake in Infants With Cleft Palate

Cleft lip and/or palate is one of the most common birth differences worldwide, affecting between 6,000-8,000 children annually in the United States alone. Infants with cleft palate commonly experience immediate feeding difficulty because of an inability to generate sufficient negative intraoral pressure for suction. Feeding inefficiency can contribute to poor weight gain, which can delay surgical palate repair and negatively affect later speech outcomes. Cleft-adapted bottles with unidirectional valves have become a frequent recommendation across North America to address feeding difficulties. Although cleft-adapted bottles with unidirectional valves are often the first recommendation made by cleft teams for infants with cleft palate, this recommendation is based on clinical expertise rather than scientific evidence.

The most recent Cochrane review evaluating the evidence for feeding interventions for infants with cleft palate was completed in 2011. The review indicated that squeeze-assisted bottles-where the caregiver squeezes the nipple or bottle base to deliver milk into the infant's mouth-were easier to use for infants with cleft palate than standard rigid bottles. Squeeze-assisted bottles are now rarely used in clinical care, as newer bottles have emerged with unidirectional valves that allow infants to play an active role in directing feeding. Updated systematic reviews from 2016 and 2023 have continued to include the same limited set of studies, primarily comparing rigid and squeezable bottles. Importantly, no studies have examined differences in milk volume intake between cleft-adapted bottles with and without unidirectional valves. Reviews spanning a 12-year period indicate that limited original research has been undertaken in this area despite the emergence and widespread use of new bottle systems.

The disconnect between available scientific evidence and current clinical practice reveals a gap in evidence-based care. Interdisciplinary healthcare providers-including primary care physicians, nurses, physician assistants, and speech-language pathologists-play a critical role in helping infants with cleft palate establish successful feeding. Consequently, evidence is needed to determine whether cleft-adapted bottles with unidirectional valves improve oral intake in infants with cleft palate. The proposed project will address this gap through two specific aims:

1. To compare milk volume intake, milk transfer rate, and feeding proficiency during an observed feeding in infants with unrepaired cleft palate using bottles with and without unidirectional valves.
2. To determine the impact of unidirectional valve use on caregiver-rated feeding quality following an observed feeding in infants with unrepaired cleft palate.

The proposed project will use a randomized design, feasible for implementation at a large metropolitan cleft center with an established clinical feeding pathway and sufficient patient volume. The study will generate preliminary comparative data to support future large-scale funding focused on feeding efficacy. Results will contribute to the development of patient-specific, evidence-based treatment pathways focused on nutrition and growth in infants with cleft palate.

Infants randomized to the experimental group will complete an observed bottle-feeding session using a cleft-adapted bottle system with a unidirectional valve. The valve is designed to support milk transfer by allowing milk to flow toward the nipple while limiting backflow into the bottle. Milk volume intake, milk transfer rate, and feeding proficiency will be measured during the observed feeding session. Caregivers will also rate their infant's feeding quality following the session.

Device: Unidirectional feeding valve

Infants randomized to the comparator group will complete an observed bottle-feeding session using a bottle system without a unidirectional valve. Infants will rely on their own sucking ability and compression of the nipple to transfer milk. Milk volume intake, milk transfer rate, and feeding proficiency will be measured during the observed feeding session. Caregivers will also rate their infant's feeding quality following the session.

Two common cleft-adapted bottle that feature unidirectional valves are the Dr. Brown's® Zero-Resistance Specialty Feeding System® (Dr. Brown's® SFS) and the Pigeon Baby Cleft Palate Bottle. The Dr. Brown's® SFS is currently the most used and recommended cleft-adapted bottle in North America. These bottles feature a unidirectional "check valve" that is inserted into the nipple of the bottle. This unidirectional valve allows milk to flow into the nipple but not back into the bottle, creating a compression nipple that extracts milk when the infant compresses the nipple with their lips, gums, or tongue

Time frame: Immediately after the observed feeding session

Total milk volume consumed (mL) during a single observed feeding session will be measured and compared between infants with unrepaired cleft palate randomized to feed using bottles with versus without a unidirectional valve.

Time frame: Immediately following the observed feeding session

Caregiver-reported feeding quality will be assessed using the feeding domain of the Infants with Orofacial Cleft: Observable Outcomes (iCOO) questionnaire. The instrument includes 10 items assessing feeding behaviors and difficulties using a three-point ordinal response scale (none of the time, some of the time, all of the time) and one item assessing overall feeding ability using a five-point ordinal response scale (excellent, very good, good, fair, poor). Caregiver responses will be compared between infants with unrepaired cleft palate randomized to feed using bottles with versus without a unidirectional valve.

Assessing the Effect of Infant-directed Unidirectional Feeding Valves on Milk Volume Intake in Infants With Cleft Palate- A Randomized Controlled Trial