Has this happened to you?
Later into your breastfeeding journey, you may notice it takes longer to trigger a let-down. This is common both with a baby at breast and with long-term pumping. What works early on may change over time.
First, rule out some possible culprits: 1) Are your pump parts worn and need to be replaced? Any kinks or tears in your tubing? Has the suction on your pump been compromised? 2) Are you about to start your period or are you possibly pregnant? Both can decrease milk production which may impact let-downs. 3) Did you recently start taking a new hormonal birth control? There are reports of hormonal BC impacting supply. 4) Are you tense, in pain, cold, fatigued or anxious? These factors may block the neurochemical pathways required for milk let-downs.
Some women report improved results later in lactation, after they change to a different pump or use a different flange that fits the breast better. Flange fit can change over time and nipples may become more elastic over time.
Have you tried a different pump to compare? Or using heat, breast massage/compressions, or vibrations to prompt milk flow? What works best for you to trigger letdowns?