Cleft lip and/or palate (CLP) is one of the most frequently occurring birth defects, affecting approximately 1 in 700 live births. A cleft of the palate (CP) creates a communication between oral and nasal cavities, making it difficult to generate negative pressure needed for proper sucking and swallowing. Furthermore, regurgitation of milk through the nasal cavity and frequent choking contribute to feeding problems in babies with CLP that can lead to low nutritional intake if left untreated. Feeding in babies with CLP on the breast is so rarely successful that the large majority of babies with CLP are fed using specialized bottles to overcome the absence of intraoral suction—often with formula instead of breast milk. Breast milk protects against infant mortality by providing antibodies, which bolster infants’ immunity to infections, diarrhea, pneumonia, and other diseases. A breastfeeding appliance (BA) that can create enough negative pressure to draw milk into the baby’s mouth can potentially allow mothers to directly nurse their babies who have CLP. In our clinical study, we gather observational data and test the ergonomics, safety, and efficacy of this BA on lactating women. The specific aims of our project are: 1) to test the prototype BA on lactating mothers to improve product design, 2) to quantify the amount of breast milk that is able to be expressed from hand compressions using the BA, and 3) to obtain a qualitative description of the appliance’s comfortability, ease of use, and effectiveness.