The breast pump flange is the funnel-shaped piece of equipment that creates a seal around the areola, drawing the nipple into its tunnel to extract milk. Achieving an appropriate fit for this shield is directly related to comfort and the efficiency of milk expression. The process begins with accurately measuring the diameter of the nipple, which determines the correct flange size necessary for the breast pump equipment.
Why Nipple Diameter Measurement is Essential
Using a flange that is incorrectly sized can lead to two major issues: physical trauma and reduced milk output. When the flange is too small, the nipple tissue can rub against the tunnel sides, causing friction, chafing, and potential compression that may result in pain and injury. A flange that is too large, conversely, may pull in an excessive amount of the areola tissue, which can lead to swelling, bruising, and discomfort.
An ill-fitting flange compromises the seal and restricts the flow of milk, leading to inefficient emptying of the breast. Incomplete milk removal signals the body to produce less milk over time. Ineffective drainage also increases the risk of complications such as clogged milk ducts or mastitis. Finding the correct diameter is therefore necessary for maximizing milk production and minimizing the chance of injury.
Preparing for Accurate Measurement
Gathering the proper tools is necessary to ensure accuracy. A flexible measuring tape or a rigid ruler marked in millimeters (mm) is needed, though printable measuring templates are also commonly used. Since nipple sizes can vary between breasts, it is necessary to measure both sides independently.
Timing the measurement is also an important factor, as the size of the nipple can fluctuate throughout the day. For the most accurate reading, it is often suggested to take the measurement after a pumping session or feeding, as the nipple tissue may swell slightly. The measurement should be taken when the nipple is relaxed, not stimulated or engorged prior to a pumping session.
Step-by-Step Measurement Procedure
The goal of this procedure is to measure the diameter of the nipple only, without including any part of the surrounding areola. The measurement must be taken across the base of the nipple, which is the widest part where the nipple meets the areola. It is helpful to use a mirror or have assistance to ensure the measuring tool is placed directly across the center of the nipple horizontally.
If using a ruler, the measurement should be recorded in millimeters, measuring the distance from one side of the base to the other. If using a specialized template with sizing holes, the nipple is placed gently into the holes until the largest size that the nipple fits into comfortably is found. The measurement taken must be the diameter of the nipple before any suction or stretching occurs from the pump itself.
Converting Nipple Size to Flange Size
An adjustment must be made to determine the appropriate flange size. The flange size should not match the nipple diameter exactly, as space is needed for the tissue to move freely during the vacuum cycle. Industry standard practice is to add approximately 2 mm to 4 mm to the measured nipple diameter.
For example, a measured nipple diameter of 17 mm typically translates to a recommended flange size of 21 mm, and a 20 mm measurement suggests 24 mm. Measurement is an initial guide, and the final confirmation comes from observing the nipple during a pumping session. A properly sized flange allows the nipple to move centrally and freely within the tunnel, with little to none of the areola being pulled in. If the nipple appears swollen, flattened, or discolored after pumping, or if there is excessive pain, a size adjustment is likely needed.