First and foremost, instead of buying best baby glass bottles, expectant mothers need to buy only a couple of them, so as to see how their baby responds to them. In case you baby responds well to a specific brand of feeding bottle, you can always opt for buying more of them in future. But, if the baby is not too comfortable with any specific brand of feeding bottle, opt for the next best available option of feeding bottle. 

Next, ensure of buying best glass feeding bottles for baby having wide based nipples, similar to a mother’s breast. This will help in making the baby comfortable when making a switchover from mother’s breast to feeding bottle nipple. The speed of nipple flow rate is likely to vary from brand to brand. In some of the feeding bottles nipples are designed for slower or faster flow of milk. However, for newborns, it is the slower flow of milk, which is comfortable and advisable. Faster flow can result in causing tummy upsets for the newborns. Therefore, prior to buying any feeding bottle, do ensure to check out the nipple flow. 

Another important and major aspect which mothers need to check while buying feeding bottles is the material quality of the product. While, plastic feeding bottles are easier to handle while feeding the babies, the chemical contents in plastic is what puts away the mothers from buying them. Next, there are classic glass feeding bottles, which although are easy to clean and maintain, can prove to be quite risky is broken, glass feeding bottles need to be handled with extra care and caution. Glass feeding bottles can be provided extra safety by covering them with cloth covers. While buying plastic feeding bottles ensure of looking out for BPA free ones which are also microwave compatible. 

In baby feeding bottles, size does matter. As babies tend to grow faster, opt for buying bigger sized feeding bottles, with easy-to-read measurements facility. This will help you in not having to change the feeding bottle on frequent basis. 

And, last, but not the least, opt for feeding bottles having clear silicone nipples rather than dark colored latex nipple bottles. The reason being, clear silicone nipples do not pick up tastes and smell even after continuous and regular use.