Why the First Two Let-Downs Matter in Breastfeeding and Pumping

By: Guest Contributor

4 min

Introduction

If you’re a new mom, you may have heard about the “let-down reflex” and wondered what it means for your breastfeeding or pumping journey. Many moms notice a tingling sensation or a sudden rush of milk early in a feeding – that’s your let-down reflex at work. Understanding how this reflex functions (and why lactation experts often emphasize the first two let-downs of a feeding) can help you maximize milk transfer to your baby and make the most of your pumping sessions. In this article, we’ll explore the science behind let-downs, the difference between foremilk and hindmilk, and practical tips to encourage those important early let-downs.

The Let-Down Reflex: Oxytocin and Prolactin in Action

The let-down reflex – also called the milk ejection reflex – is an automatic process that makes your milk start flowing when your baby begins to nurse. When your baby suckles at the breast (or when you stimulate your nipple by pumping), tiny nerves send signals to your brain, triggering the release of two key hormones: prolactin and oxytocin (1). Prolactin helps produce and refill your breast milk, essentially telling your body to make more milk. Oxytocin , on the other hand, causes the milk-making cells in your breast to contract and squeeze out milk, pushing it down the ducts and out through the nipple (2). In simple terms, prolactin fills the breast with milk, and oxytocin empties it.

This hormonal teamwork is what causes that gush of milk at let-down. Oxytocin even makes the milk ducts widen, making it easier for milk to flow (3). Some moms feel the let-down reflex as a tingling, warmth, or a sudden fullness in the breast, while others don’t feel a noticeable sensation – both are completely normal (4). Even if you don’t physically sense it, you’ll usually see signs of let-down: your baby’s quick, shallow sucking will switch to a deeper, slower suck-swallow pattern once milk is flowing (5). You might also see milk dripping from the opposite breast or feel a strong thirst (thanks again to hormones) (6).

Often, a let-down can become a conditioned response. Many moms find that just hearing or seeing their baby (or even thinking about them) can trigger a let-down, as oxytocin kicks in from emotional cues (7). That’s why you might leak a little when your baby cries or when it’s about time for a feeding. This is a natural reflex to help ensure milk is ready for your baby when they need it.

However, the let-down reflex isn’t always instantaneous or consistent, especially in the early weeks. Stress, pain, or even being rushed can interfere with oxytocin’s effects – in fact, stress hormones can slow down or delay your let-down (8). Don’t worry – feeling frustrated or tired won’t dry up your milk supply immediately, but it might make let-down take a little longer in that moment. The good news is that with practice and time (usually after the first couple of weeks of regular feeding), your let-down reflex becomes more conditioned and automatic (9).

Multiple Let-Downs: Why the First Two are So Important

Many people assume there’s only one let-down per feeding, but most mothers actually have multiple let-downs during a nursing or pumping session. In fact, it’s common to have 2–4 let-downs over the course of one feeding (10). Babies are clever feeders – they tend to start with quick, light suckling to trigger the first let-down, then switch to slower, more rhythmical gulps once the milk is flowing (11). After the initial flow slows down, your baby may again start sucking faster to stimulate a second let-down, and you’ll notice another wave of deeper gulps when that next surge of milk comes.

The first let-down generally happens within the first minute or two of nursing or pumping (12), releasing a good volume of milk. After that initial gush, the flow may pause or slow. That’s when the second let-down becomes important. When your baby continues to nurse (or you continue pumping), a few minutes later another let-down reflex will send more milk flowing (13). The first let-down provides a large volume of milk, and the second let-down brings additional milk – often richer milk – to keep your baby fed and full (14).

Pumping Strategies for Maximizing Let-Downs

For pumping moms, choosing the right pump and techniques can make a significant difference in stimulating multiple let-downs and maximizing milk output.

Choosing the Right Pump

Many moms find that hospital-grade and high-double electric personal pumps are excellent at mimicking a baby's natural nursing rhythm. The Spectra S1 and S2 pumps, for example, offer customizable settings, including a "massage mode" that helps stimulate the let-down reflex more effectively (15). Legendairy Milk’s Imani i2 wearable pump is another great option for moms on the go, offering hands-free convenience without compromising suction strength (16). Choosing a pump that allows for easy adjustment of cycle speeds and suction levels can help optimize the let-down response.

Techniques to Encourage Multiple Let-Downs

To ensure you’re getting at least two let-downs per session, try these strategies:

Start with stimulation mode: Most pumps have a "let-down mode" that mimics a baby’s quick suckling. Begin your session with this setting to trigger the first let-down (17).
Use hands-on pumping: Massaging the breasts while pumping can help move milk through the ducts and encourage additional let-downs (18).
Pump past the first stop in flow: When the milk flow slows, switch back to stimulation mode for a few minutes to trigger another let-down (19).
Relax and minimize stress: Try listening to calming music, looking at a picture of your baby, or practicing deep breathing exercises while pumping to help oxytocin release (20).

By combining the right pump with effective techniques, you can optimize your let-downs and maximize your milk output, making pumping more efficient and rewarding.

Conclusion

Understanding the importance of the first two let-downs can make a big difference in both breastfeeding and pumping. These early let-downs ensure your baby gets both hydration and the rich, calorie-dense milk they need for growth. Whether nursing directly or using a pump, using the right techniques—such as warm compresses, massage, and let-down stimulation modes—can help trigger multiple let-downs and improve milk output. Choosing a high-quality pump, can further enhance milk expression efficiency. Ultimately, the more informed and relaxed you are, the easier it becomes to support your milk flow and provide nourishment for your baby. Happy feeding!

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