Instruct: Classify a review into positive or negative sentiment.
Query: DESIGN FLAW THEY LEAK.

At first we loved these bottles (not many parts, easy to read) then we noticed that they have a tendency to leak milk by the seam. We contacted Philips and they said you must wet the seal completely to prevent leaking we tried that and they still leaked about 1/3 of the time. So we went out and bought Dr Browns and are giving the Avent away. The Dr. Browns are made in the USA and have more parts but our baby seems to like them better, less fussy and less drool while eating.