Expert answer: The BabyCenter Editorial Team
As soon as your baby can sit without support, which can be as early as 6 months, he or she can ride in a grocery cart's child seat. At this age, however, your baby may not be able to sit steadily for the length of a shopping trip.
Never let your baby ride in a cart without a seatbelt, and don't let him or her stand in the cart or climb on it. Grocery carts tip over very easily – an average of 21,600 children are injured in shopping cart accidents each year, according to the Consumer Product Safety Commission.
If you have an infant car seat carrier, it may be tempting to wedge it into the cart, but this, too, is a risky practice. The car seat could slip out or cause the cart to topple over. Some grocery stores provide carts with built-in infant seats. If you don't see one when you arrive at the store, ask a clerk if there are any available.
You might want to purchase a seat insert to keep your baby more secure in shopping carts – this can be a great thing to have when a cart's seat belt is broken, missing, or flimsy. Seats such as these are often padded, making for a more comfortable ride, and many cover up grimy grocery cart handles, protecting your baby from germs.
Some parents sing the praises of baby slings or front carriers – either of which can help you keep both hands free while you're grocery shopping. Others find it convenient to keep their baby in the stroller, placing groceries in the underseat basket.