It's somewhat common for babies and toddlers to get general anesthesia at least once for routine procedures such as tonsil removal, hernia repair, or surgery to insert ear tubes. Usually these surgeries don't last more than an hour.

In the past, parents and anesthesiologists have had concerns about giving general anesthesia to young children because some studies on animals suggest that large doses could damage the brain. Some parents delay surgery until children are older for this reason. Scientists still aren't sure whether longer or repeated doses of anesthesia might have a lasting impact on baby's brains.

In the latest study, published in the journal The Lancet, researchers recruited more than 700 babies across seven countries in order to investigate the effects of general anesthesia on human children. All of the babies needed hernia repair. Each was randomly assigned to get either general anesthesia or a local, spinal anesthesia for the hour-long operation.

When the children turned 5, researchers tested their IQ, memory, attention, executive function, and behavior. The kids had similar scores, regardless of whether they received the general anesthesia or local anesthesia.

The researchers conclude that parents don't need to delay brief one-time surgeries for babies and toddlers out of concern about the effects of general anesthesia. Large, randomized controlled trials are regarded as one of the best ways to conduct medical research, which gives this study's findings a lot of weight.

Even so, some questions remain. Most of the babies in the study were boys, so it's possible girls might react differently to general anesthesia.

Also, the study didn't test longer or repeated exposure to general anesthesia, which some other studies suggest may be harmful. As a result, in 2017 the Food and Drug Administration issued a warning about long or multiple anesthetic exposures with children under 3 and with pregnant women.

That doesn't mean you should delay surgery for yourself or your child if it's medically necessary. Be sure to talk to your doctor if you have questions or concerns.