This product is widely reviewed, so I will try not to completely repeat what others have said. I have unexplained low supply, but desperately wanted to establish a breastfeeding relationship with our second little guy, after being unsuccessful with our first. There are two at-breast supplementers available for helping Moms do this when they do not make enough milk to sustain their babies: the medela SNS and the Lact-Aid. I began with the SNS and while my experience was not bad, I wasn't a huge fan of this somewhat large, plastic bottle hanging from my neck, against my skin, and sometimes bopping my son in the head if I tried to move in certain ways while nursing. After 2-3 weeks with the SNS (every nursing, 8-11 nursings a day), I decided to try the last-aid after reading about it and how it is supposed to encourage a nutritive suckling vs. just suction to accomplish the goal of milk transfer. In my case, all it took was one nursing with the lact-aid and our SNS has been shelved since then. I will keep it undoubtedly as a back-up, but I have no desire to use it. Here are some pros and cons:
SNS Pros:
*All parts re-usable, though the tubes may wear over time and need replacing
*Fairly easy to use and refill when away from home (especially if you are comfortable without having to fully clean in between uses here or there, some people are not though)
*Being able to "pinch" off the tubes so that no milk flows if you want to encourage the baby to nurse from you first, then be able to open the tubes when you choose
SNS Cons:
*Bulky, cannot imagine trying to use it discretely in public
*The 2 tube system (using one for a vent) can be tricky at times and a little annoying to deal with (how we dealt with it was taping one tube up on the bottle; we never taped one to each breast as it shows, that wouldn't seem like it would work to me, but evidently others have success)
*Milk sometimes leaked or dripped from tubes while waiting to get my son latched or if he unlatched during a nursing
Lact-Aid Pros:
*One-tube system, which in my experience I was actually LESS likely to have leaking or milk dripping from the tube without his actively nursing to pull it through (though from reading other reviews, it seems maybe I am in the minority?); most of the time, if he unlatches or pulls away, the milk goes back up the tube and does not drip or leak while I am relatching him
*Feels better against skin, especially with optional cloth bag to hold the milk storage bag
*Slightly more discreet than the SNS, even more so if you can master the process without the use of tape (which I have not yet been able to do routinely)
*Encourages gentler nursing, at least in my experience; I truly felt a difference from the first time my son nursed using the lact-aid vs. the SNS; with the SNS it felt like hard suction and the nursings took longer as well, sometimes by double and then some (what my son could drink in 10-15 minutes with the lact-aid was taking 30 minutes with the SNS and with the greater suction, the wear and tear on my nipples and my comfort was significant)
Lact-Aid Cons:
*Disposable bags =( This was a big bummer in my book, and I admit I do reuse the bags a few times before throwing them out which is not advised, but I strive to reduce waste as much as possible and this was probably the biggest con for me about the lact-aid
*The tube is shorter than the SNS tubing, which can also be a PRO, but for me, it is a slight con as with the SNS, I actually often ran the tube from under my breast and it was more out of the way and with the lact-aid I cannot do that
*While there is a way to "pinch" off the tubing, with the shorter length, I find I cannot do this (this may also have something to do with the fact that I prefer the bag or bottle, in the case of the SNS, off to the outside of the breast I am nursing on vs. hanging between my breasts, as this way it is not in my son's way or touching him really)
*Not practical to refill when out and about
In my book, cleaning either is not particularly fun, so I didn't list that as a pro or con on either end. It may appear surprising, when I list it out like this, that the lact-aid is my preferred method for at-breast supplementation! For me, the pros of the lact-aid outweigh the cons, as well as outweighing the pros of the SNS. The big one is just that it has a better overall feel than the SNS to me--no hard plastic against me or my baby, only one tube making it seem simpler overall, and my son nurses more effectively and yet more gently at the same time making nursing more enjoyable all around. If you have a baby who won't latch, neither will truly be successful for you, and in that case, working with a certified lactation consultant will be key. A baby needs to be able to latch and nurse effectively to pull milk from these systems.
One last word for Moms struggling with low supply who do not want to give up and truly value the breastfeeding relationship....ignore all the nay-sayers and try a system like this or the lact-aid to help you reach your goals, even if your goals have to be adjusted from what they originally were. As I like to tell myself when I am feeling rough about not being able to produce enough for my son, we still have a great breastfeeding relationship, it just has extra parts. ;) And check out the book Making More Milk by Diana West and Lisa Marasco.