Your go-to guide for choosing how (and when) to collect milk and letdowns.

Maybe you’ve been here before: You’re nursing on one side when you start leaking on the other. Frantically, you search for something to catch your milk while trying not to interrupt your voracious baby––but every drop counts! Or maybe your baby unexpectedly sleeps through a mid-night feeding (yay!), but now you’re engorged (less yay). You’re not sure you want to connect your pump for a full session, but you’ve got to relieve this pressure. What do you do?

Each of these issues could be solved with either a catch cup or a passive pump, respectively, which are the primary tools to catch milk during breastfeeding. Each serves a unique purpose, so it’s important to know which is best for your nursing and pumping needs. In this article, we'll cover: 

• What are passive pumps and catch cups
• Key differences
• Pros and cons of each
  
• Willow options
• Which is right for you?

What are Passive Pumps and Catch Cups? 

Before we determine which nursing support is best for you and your lifestyle, let’s dive into how each product works and in which instances.

A passive pump is a non-motorized, manual pump that sits in-bra and creates gentle suction. It collects and expresses milk without stimulating oversupply. These are perfect for “taking the edge off” in between feedings. They can be worn for a few minutes to quickly relieve pressure before pumping or feeding, or in between feeding sessions if your baby isn’t ready to nurse. They can also be extremely useful while weaning––for when you want to gradually diminish your supply, but never waste a drop in the meantime. You can also wear them for the entire length of a feed to catch leaks while nursing or pumping on the other side; however, that’s also the primary purpose of a catch cup.

The role of catch cups is to effortlessly catch leaks and let-downs while protecting sensitive nipples. Your doctor or your lactation consultant may even suggest wearing them between nursing sessions so new-to-nursing nipples have a moment “to breathe” without the friction of a bra or t-shirt. 

Willow Silicone Wearable Breast Pump

Willow Catch-All Milk Cups

Milk Volume, Comfort & Mobility: Key Differences Between Passive Pumps and Catch Cups

The TLDR: Both passive pumps and catch cups collect leaking milk. But passive pumps have suction, and catch cups do not. So how does a passive pump work, exactly?

Passive pumps use suction to create an airtight seal around the breast. Once you align the pump over your nipple, you squeeze the pump (also known as the “bulb”) to determine the level of suction: The more you squeeze, the more intense the suction will be. Passive pumps will typically yield a bit more milk than catch cups since they passively create suction. 

Both are designed for comfort and ease of use, and both allow you to seamlessly transfer collected milk into a breast milk storage container. All catch cups sit in-bra, but not all passive pumps do, which is where the Willow Silicone Wearable Breast Pump differs from other passive pumps on the market. Both help moms have the convenience they deserve, with the mobility and maximum discretion they crave.

Pros & Cons of Passive Pumps

Pros

The greatest benefits of passive pumps are that, due to their gentle suction, they are most efficient at collecting more milk during letdown. They are ideal for moms looking to relieve engorgement or when regulating supply in early breastfeeding. Their comfort, discretion, and ease of use are hard to beat when in need of a quick solution.

Potential Cons

Passive pumps are not meant to fully empty the breast, which is why they usually hold between 3–5 oz. of milk. If you’re looking to pump more milk and, therefore, want a larger storage capacity, consider an electric pump. One potential drawback of passive pumps, depending on your feeding goals, is that their suction extracts milk instead of simply collecting it––which means that if used too frequently, you may be impacting your supply (which may cause you to overproduce). This could take milk away from your baby, which could impact their growth and/or your feeding schedule. Passive pumps are meant to be a tool for occasional use instead of a go-to, everyday solution. 

Pros & Cons of Catch Cups

Pros

The benefit of catch cups is that they are discreet, lightweight, and perfect for everyday use. They are small and pliable enough to fit easily within diaper bags and are perfect for collecting leaking milk no matter where you go, effectively protecting your clothes from milk leaks. They are also excellent in the early days of breastfeeding to prevent sensitive nipples from rubbing or chafing against fabric. 

Potential Cons

Catch cups are meant solely as a way of supporting your nursing and pumping journey. For this reason, as well as their lack of suction, they are not ideal for moms looking to significantly boost their milk supply.

Pumping With A Healthy Supply In Mind? Try a Willow Wearable

For all this talk about catch cups and passive pumps, it’s important to know that Willow electric pumps are an optimal solution if your primary goal is to extract milk and maintain a healthy supply, whether you’re exclusively pumping, nursing and pumping, or even combo feeding. Willow pumps are hands-free, hospital-strength, app controlled, and come with unbeatable customer service.

In fact, Willow wearable pumps were recently rated #1 in customer satisfaction, as well as the pump most likely to be recommended by pumping moms––and that was not just the wearables category, but among all breast pumps surveyed!* While Willow currently makes two award-winning wearable breast pumps, we also have a wealth of supporting accessories to ensure mom can feed her way. Plus, all Willow pump purchases gain access to free support from our Mom Coaches, free troubleshooting advice, and 24/7, U.S.-based customer service for real-time assistance. 

Willow Go® Wearable Breast Pump

What makes the Willow Go unique in its optimization of comfort and maximum output isn’t simply one innovative feature: It’s the sum of its perfectly engineered parts. Thoughtfully designed features––from a longer, smoother flange to a circular motor, natural suction rhythm, and customization––enhance comfort, therefore triggering oxytocin, which leads to more letdowns and milk output. 

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Willow 360® Wearable Pump

What’s groundbreaking about the Willow 360 is that it’s the only pump that offers 100% leak-free mobility (while also being hospital-grade, app-controlled, and designed for maximum comfort and milk output!). Our proprietary closed-system technology means that when Willow 360 milk bags are secured in the 360 container, you can pump in any position––and never miss a drop. It’s also compatible with the Apple Watch and is ideal for pumping moms who spend long hours on their feet and need an easy, hygienic way to pump and store milk. Think: doctors, nurses, teachers, and first responders.

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Everything You Need to Feed Your Way

Yes, we make breast pumps, but that’s just the beginning. Our primary goal is supporting moms, and we do that through a variety of accessories (looking at you, spacious backpacks, and milk storage accouterments). The Find Your Flow Feeding Kit is mom’s go-to set of essentials for breast care in the early days of feeding and beyond; the Travel Cleaning Pack lets you clean and care for your pump parts on the go. There’s something for every nursing mom on any part of their journey.

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What To Consider When Choosing a Milk Collection Mode  

There’s no one-size-fits-all milk collection tool (or anything motherhood-related, for that matter). What’s important to consider when preparing your feeding “toolbox” are: Your lifestyle and convenience needs, breastfeeding goals, and budget.

Lifestyle and Convenience

What does your day-to-day look like? How much free time or flexibility do you have to pump or nurse your baby? Will you be working or caring for other children during the day? Will you be away from home? Depending on the answers to these questions, you may use both catch cups and passive pumps or choose one over the other. Both are excellent ways to manage your milk supply, whether you’re looking to increase it, maintain it, or diminish it. It just depends on whether you’d like suction to passively pull out milk or simply need a container for catching letdowns.

Breastfeeding Goals

Both passive pumps and catch cups offer incredible convenience (especially considering the mobility and discreetness of the Silicone Wearable Breast Pump). Your choice of the two may depend on your milk supply––if you’re an oversupplyer, you may not want a passive pump to pull out milk, or you may rely on it to relieve engorgement. If you’re exclusively nursing, you may find catch cups most convenient to catch leaks on the other breast. No matter your breastfeeding end goal, both options are an easy and accessible way to collect milk.

Budget Considerations

Whether you choose a passive pump, catch cup, or wearable pump will ultimately depend on how the cost stacks up against your intended usage. If you’ll be exclusively pumping or pumping in addition to nursing, a wearable electric pump is an important consideration, as it will help you set up and maintain a healthy supply for the long haul. If you’re exclusively nursing, having catch cups and a passive pump may be a more cost-effective option. Either way, you may want to consider support products like the Find Your Flow Feeding Kit, which bundles the best of the breast care at an accessible price to help you get set up for a successful feeding journey. Remember to check with your insurance provider or HSA/FSA plan to see if you can get your breast pump or accessories for free or at a lesser cost.

Find The Right Milk Collection Tool For You

There’s a lot to consider when choosing all the products for breastfeeding and pumping success. Remember: Passive pumps create gentle suction and can be worn while nursing on the other side or in -between pumping and feeding sessions to gently induce letdown and relieve discomfort. Catch cups also sit in-bra, but have no suction. Whichever you choose, we’re here to help make sure you never miss a drop.

Want more power? Shop Willow Wearable Pumps

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FAQs:

1. What is the difference between a passive pump and a catch cup?

• A passive pump uses suction to actively draw milk during letdown, while a catch cup simply collects the milk that would otherwise be lost without applying suction.

2. Which is better: passive pumps or catch cups?

• The choice depends on your needs. Passive pumps are great for collecting more milk and boosting supply, while catch cups are discreet and ideal for light collection.

3. Can I use both passive pumps and catch cups?

• Yes, many moms use both tools for different situations. Passive pumps are great for increasing milk storage, and catch cups are perfect for light collection during feeding.

4. Are wearable pumps better than passive pumps or catch cups?

• Wearable pumps like the Willow Go® and Willow 360® offer hands-free convenience, higher efficiency, and more mobility compared to traditional passive pumps or catch cups.

5. How do I choose the best milk collection tool for my needs?

• Consider your lifestyle, breastfeeding goals, and budget. Passive pumps are ideal for boosting supply, catch cups for discretion and wearable pumps for all-in-one solutions.

*Brandtracker independent survey by Rabin Roberts Research of 500 pumping moms, November 2024