Throwing up formula

[hopingforit]

My twins are 1 month old and I have been feeding them pumped breastmilk from the time my supply came in on day 3. I make 160-180ml per pumping session but between the two of them, they are taking 200ml plus they feed more frequently than I can pump in the evenings. So, I've tried giving formula as a supplement several times. Everytime I do, they throw it up...not just spit up. They keep throwing up several times before we can even get through half of a bottle. I've tried burping them more frequently, mixing it with breastmilk, only giving it at the end, giving entire bottles of it instead of giving both breastmilk and formula but nothing works. They also get very cranky. Has anyone had this problem before? My husband wants to try a sensitive formula but he is allergic to cows milk so is it possible that this is an allergy to the milk? I just don't know what to do because they won't get enough if they keep throwing it up. They have been gaining great on breastmilk alone. I'm just afraid they will lose when they throw everything up. Advice is greatly appreciated.

We've tried the following formulas in the last month and all have the same result:
Similac premature
Enfamil premature
Enfamil newborn
Similac neosure
Similac blue lid

 

[ke29]

Do they vomit if they had a full BM feed? If not I would say it is a likely cows milk intolerance.

 

[hopingforit]

They sometimes spit up a little on BM but they don't throw it up.

 

[ke29]

Would get it checked out with a doctor then.