You can read a more in-depth piece from Dr. Robert Steele (a board-certified pediatrician) about sterilizing not being necessary and why. (He also recommends sterilizing in the case of well water, though). Also, the following other medical sources agree that sterilizing bottles (outside of the first use and, of course, providing your water supply is safe) is not necessary when they are cleaned properly:
- Dr. Vincent Iannelli, Pediatrics Guide and board-certified pediatrician, in his article "Common Pediatric and Parenting Myths" -- "If you live in a city with sanitized water and you are preparing bottles one at a time, then boiling water or sterilizing the bottles and nipples probably isn't necessary. You can use this water out of the tap and bottles can be washed in hot soapy water or in the dishwasher. If you are not convinced that your water supply is safe or if you are using well water, then you should boil the water for five minutes before preparing formula."
- Dr. Ari Brown, Harvard-trained pediatrician in her book Baby 411 -- "You don't need to sterilize the bottles after the first time you take them out of the package ... Sterilizing bottles and boiling water are all based on the kitchen chemistry our mothers and grandmothers performed to prepare formula in the olden days."
- Dr. Glade B. Curtis, board-certified OB/GYN and co-director of Health Clinics of Utah, says in his book Your Baby's First Year -- "There is no need to sterilize bottles on a regular basis unless you use well water. In that case, boil bottles and nipples for 5 minutes."
- From WebMd: "In the old days when water supplies were not reliably clean, it made sense to sterilize. But now, sterilizing bottles, nipples, and water is mostly unnecessary. Unless your water supply is suspected to harbor contaminated bacteria, it is as safe for your baby as it is for you. There is no reason to sterilize what is already safe."
- The American Academy of Family Physicians: "You should sterilize bottles and nipples before you use them for the first time. You can do this by putting them in boiling water for 5 minutes. After that first time, you probably don't need to sterilize them again. Instead, wash bottle, nipples and caps in hot, soapy water. Rinse them carefully. You can also run them through the dishwasher, which kills more germs than washing by hand."
- KidsHealth.org: "Yes. Before the first use, you'll need to sterilize nipples and bottles in a rolling boil for 1 to 5 minutes. You can also sterilize them with a store-bought countertop or microwaveable sterilizer, but boiling works just as well and costs nothing. After that, you'll need to wash bottles and nipples in hot, soapy water (or run them through the dishwasher) before every use."
"Wells are not dirty, contaminated water in need of sterilization. I do have a filter and I have my well water tested yearly. It is very safe and cleaner than most tap water. To say that having a well means you should sterilize your drinking water is absurd."
I certainly wasn't implying that your well water (or anyone else's) is a big ole nasty cesspool of gunk. I grew up with well water, myself. But unless you have an exceptional filter, which many with wells do not have (including my own parents who also happen to live in an area where there have been problems with septic systems) then your water can contain harmful bacteria that aren't normally present in municipal water. Even if you have a filter, it may be one that does not remove bacterial contaminants as some only remove things like lead and chemicals. Wells near farms where runoff can occur also present a special set of problems. (Of course you also have the advantage of not having fluoride and antidepressants in your water as in some municipal supplies...) At any rate, you also get your well water tested once a year, which is great, but again, not everyone does. It sounds like you have your well situation fully under control and so this advice probably doesn't apply to you.
For those of you who do sterilize your baby's bottles and nipples before use (40 percent of you say you do), what are your reasons? Were you advised by your health care provider or someone else? I recently read a message board where a mother questioned other's advice to not sterilize with, "Are you people MAD??!! Do you know how easy babies pick up diseases?" So, I know there are people who feel strongly about their preference to sterilize or not to sterilize. Another thing that crossed my mind is that when I was traveling recently, I was in a hotel and happened to turn on the local cable access channel. There I saw a warning about that city's water being contaminated and residents were being advised to boil water. If I lived there (or was traveling with a baby and assumed the water was safe) and hadn't gotten the notification yet, then perhaps routine sterilization procedures would have prevented an illness. Maybe...