One of the benefits of having had much older relatives and my own adult-aged kids who are spaced ten years apart in age is I have seen, heard, and read nearly everything on baby care and child-raising trends.  While some examples are potentially harmful, most are simply timely and humorous.  

First example:

An "expert" from generations past:  "If you want your child to be healthy, make sure he is fat enough!"

The first pediatrician I encountered:  "Don't let him gain too much weight--  you don't want him to get fat!"

Second example:

My first child's pediatrician:  "Never give him cow's milk--  cow's milk is for calves!"

My second child's pediatrician:  "Have you switched her over to cow's milk yet?"

Third example:

First pediatrician:  "Of course you should use a bottle--  breastfeeding is for animals."

Second pediatrician:  "Why are you using a bottle--  don't you know breastfeeding is better for a baby?"

Fourth example:

Advice I received for first child:  "Add a couple spoonfuls of cereal in his night bottle--  it's nutritious and helps a baby sleep better."

Advice I received for second child:  "Never put cereal in a baby's bottle--  it's lazy, and the baby doesn't need it."

Well, you get the picture.  :)

In recent years, I've seen the trend of using pacifiers.  I've also heard from a couple of first-time mothers that their obstetricians advised them to smoke marijuana during pregnancy, to reduce morning sickness.  I think they're clear examples that the "experts" often do not know what is best at all.  It's better for moms and moms-to-be to rely on their own instincts and common sense.  After all, if the experts really did  know what they were talking about, "trends" would not change every few years.