Weaning: What, When, and How

12 Months: Ease Off the Bottle

For babies accustomed to formula or expressed milk, the idea of giving up that familiar, easy-to-use vessel for a more challenging sippy cup is torture. So why the swap? It's all about your tyke's teeth. Staying on the bottle too long is the chief culprit behind tooth decay, especially if Baby takes her beverage to bed. "Her teeth will be coming in any day, and the milk will coat them in sugar, creating a breeding ground for cavity-causing bacteria," West says. Plus, drinking while lying down ups the risk for ear infections. What's more, bottle-feeding your child cow's milk (which has less iron than infant formula) past 12 to 18 months increases her risk for an iron deficiency and anemia. If she's still taking the bottle, she's less apt to fill up with iron-packed foods.

Start weaning Baby when she turns 1. "By 18 months at the latest, she should be drinking from a sippy cup," says Dr. Greene.

Break the Habit Give her a sippy cup of formula or breast milk (or even an empty cup) before her first birthday, so she gets used to holding it, but don't expect her to use it yet. Once she's 1, put milk in the cup and, over a few days, offer her fewer bottles, Dr. Greene says.

Yes! Weaning Success! "Our son, Ben, refused to drink from his sippy cup at first. So before naps and bedtime, we offered only water in his bottle and milk in the sippy. When Ben would hand the bottle back saying he wanted milk, we'd tell him, 'The milk is here in the sippy.' Within a few days, he was taking the sippy," says Wendy Martinez, of Dallas.