Slideshow: Bottle-Feeding and Infant Formula

Your baby may give you clues about which they like better. Plastic bottles are lightweight and shatterproof but may not last as long as glass. In the past, some parents chose glass to avoid a chemical called bisphenol A (BPA) that was used in some plastic bottles. Now, all plastic bottles sold in the U.S. are BPA-free. Hybrid bottles are plastic on the outside so they don’t break, with a glass liner between the plastic and the formula.

Most are made of silicone or latex, and they come in various shapes. They sometimes have different "flow rates," based on the size of the nipple's hole. You may want to try several types to see what your baby likes and can drink easily from. Check nipples often for signs of wear or cracking. Replace any that are worn or discolored.

You can wash them with detergent and hot water, by hand or in the dishwasher. Do it each time you use them. You may prefer to wash plastic bottles by hand, since some studies show that chemicals leak from plastic when it's exposed to hot temperatures.

Give your newborn only pumped breast milk or formula in the bottle -- no water or juice. Mix formula exactly as it says on the label. Adding too much water thins the formula, skimping on nutrition. And it may cause low salt in the baby, which can lead to seizures. Too little water may be hard for your little one's stomach and kidneys.

Most parents start with one made from cow's milk. You can also buy soy and hypoallergenic kinds. Make sure you use one that's iron-fortified. You can buy formula in powdered, concentrated, or ready-to-use forms. By 6 months, your baby should be drinking between 6 and 8 ounces per feeding.

It's fine to give your baby a cool or room-temperature bottle. If they prefer warm formula, put the filled bottle in warm water or run hot tap water over it for 1-2 minutes. Or you could use a bottle warmer. Don't use the microwave. It can cause hot spots that could burn your baby's mouth. Shake the formula and put a drop on the top of your hand to test the temperature. Don't test it on your wrist -- it's less sensitive to heat.

Put a bib on them, and have a cloth ready to clean any spit-up breast milk or formula. Now, cradle them with their head a bit higher than the rest of their body. Hold the bottle and watch them eat. Watching your baby will help you know when they have finished. Try to burp them halfway through the feed to help limit spit-up.

When you're tired, it can be tempting to prop up the bottle on a pillow and let your baby feed themselves. But there are lots of perks if you hold the bottle while they eat. It’s great for bonding, and it’s safer. Leaving your baby with a propped-up bottle makes choking and tooth decay more likely. It can also cause ear infections. So enjoy your bottle time!

Your little one will let you know when they are finished feeding. They may stop sucking, turn away from the bottle, or, if they are old enough, push the bottle away. Give them a chance to change their mind, but don't make them finish what's in the bottle. If your baby tends to spit up after feeds, you may need to give them smaller but more frequent meals and keep them upright for 20-30 minutes afterward (but not in a car seat).

If your baby needs a burp during or after feeding, hold them on your lap or rest them on your shoulder. Gently pat or rub their back. You can also sit them on your lap, supporting their head, while you pat their back. They may spit up some milk, so have a cloth handy. If they don't burp after a few minutes but seem content, don't worry. Not every baby burps after every feeding.

If your baby spits up a lot, burp them every few minutes during feedings. Don't lay them down or play with them for 45 minutes after they eat. Hold them upright or prop them up in a car seat after the meal. Spitting up often gets better when a baby starts sitting up. If you're worried about how much they spit up, talk to their pediatrician.

If your baby spits up a lot or is fussy, you might blame the formula. Sometimes, babies can have allergies that can cause things like diarrhea, vomiting, or dry, red skin. If you see this, talk to your little one's doctor. They'll tell you if you need to change formulas -- and if so, how to do it best. Don't make a change before you talk to the doctor.

Make formula as needed. Don't mix big batches. Always throw out formula that's left over in the bottle. Refrigerate opened packages of liquid formula right away, and use them within 48 hours. If you have mixed formula from powder, you can store it for 24 hours in the fridge. If formula is left out more than 1 hours, throw it out. Refrigerate breast milk for use within 7 days. Or freeze it. Breast milk can last 3 months in a regular freezer that’s kept at 0^o F, or 6 months in a deep freezer.