Impact of Breast Shield Designs on Dynamics of Breast Pumping

A prospective, randomized, 2-phase/crossover, single center premarket feasibility study. In phase I the comfort will be assessed, the occurence and types of adverse events will be recorded and the assessment how and if the different breast shield designs interact with the lacting breast during pumping. Phase II takes place at home; assessment of adverse events will be recorded and the assessment how the subjects perceives the comfort of the soft edge breast shield during mid term use at home.

This is a prospective, randomized, 2 phase/crossover, single center premarket feasibility study enrolling a total of 15 subjects. Follow up visit will be after 14 days. The study will be divided in two phases. The objectives of phase 1 are: * assessment of Comfort (subjective) * occurrence and types of adverse events * to assess if and how the different designs (shapes and soft edge) of the three provided breast shields interacts with the lactating breast during pumping, with regards to: * The influence of nipple size, diameter and length (measured before pumping) * Maximum comfortable vacuum selected by participant (mmHg) * Actual vacuum generated in the tunnel of the breast shields in relation to the vacuum level indicator of the breast pump (mmHg) * Characteristics of nipple movement in the tunnel during pumping * Amount of tissue entering the tunnel at maximum applied vacuum (mm) * Amount of tissue entering the tunnel at minimum applied vacuum (mm) * Space between breast and shield (mm) The objectives of phase 2 are * to assess how the participants perceive the comfort of the soft-edge breast shield during mid term use at home * to assess which adverse events occur Study procedures - Phase 1 The participant will be invited for a pumping session (3 times 2 minutes of expression) at Medela Headquarters. The CE-marked Freestyle breast pump and its pumpset will be used in the both phases of the study.The participants will be asked to pump 3 times with each of the 3 breast shields in a randomized order. Each pump session (defined as pump start till pump stop) will be short (2 minutes of pumping after milk ejection has occurred), and all three short pumping session will be done on the left side only. All pump session will start with the stimulation mode and change to expression mode as soon as milk flows. Study procedures - Phase 2 Once the debriefing is finished the participants will be instructed about the Phase 2 (home use) part of the study and its equipment to be used. Study subjects that do not have a Freestyle system in use, a system will be provided. All subjects will be provided with the applicable breast shield types and introduced as well as the new shields will be handed over. * the soft-edge breast shield (non CE-marked) and * the modified PersonalFit Breast Shield (non CE-marked) This part will start for each participant the day after the phase 1assessment at Medela Headquarters. Day 1-7 (Evaluation of pumping experience with the modified PersonalFit breast shield) Day 7 (Comfort evaluation of the modified PersonalFit breast shield) Day 8-14 (Evaluation of pumping experience with the soft-edge breast shield) Day 14 (Comfort evaluation of the soft-edge breast shield)