The benefits of breast-feeding are well established. Breast milk contains the right balance of nutrients for your baby, and the antibodies in breast milk boost your baby's immune system. But in some cases, exclusive breast-feeding isn't possible or practical. The decision to use formula shouldn't lead to guilt, says Jay Hoecker, M.D., a pediatrician at Mayo Clinic, Rochester, Minn.

Here, Dr. Hoecker answers important questions about breast-feeding and infant formula.

Breast-feeding for at least four months helps boost your baby's immune system. Breast-feeding throughout the first year is ideal. Most breast-feeding mothers in my practice wean their babies between ages 9 and 15 months.

Taking good care of yourself can go a long way toward promoting successful breast-feeding. Eat healthy foods, drink plenty of fluids and rest as much as possible. To boost your confidence, learn as much as you can about breast-feeding. Keep the environment calm and relaxed. Look to your partner and other loved ones for support. If things aren't going well, ask for help. Friends who've successfully breast-fed may be a good source of information. Lactation consultants are available at many hospitals and clinics. Your baby's doctor can help, too.

Breast milk is the best food for babies — but risk is a relative term. Although breast-feeding your baby is certainly beneficial, proper nourishment is absolutely necessary. If breast-feeding isn't working for you despite your best attempts to succeed, your baby may not receive adequate hydration or nutrition. In this case, sticking with it for your baby's sake may pose serious risks.

Commercial infant formulas don't contain the immunity-boosting elements of breast milk. But when prepared as directed with clean water, infant formula poses no risks to healthy babies with typical dietary needs.

Many mothers successfully combine breast-feeding and formula-feeding. If exclusive breast-feeding isn't possible or practical for you, remember that babies need consistency. Determine the right compromise between breast-feeding and formula-feeding and follow a consistent schedule.

Guilt has no place in a thoughtful decision about breast-feeding. Instead, focus on your baby. Nurture your baby, and make sure he or she is well nourished. Don't feel guilty for doing what makes the most sense for you and your baby — whether it's combining breast-feeding and formula-feeding or using formula exclusively. If you're struggling with your decision not to breast-feed, it may help to share your feelings with your baby's doctor or another caring and knowledgeable person.