They think you're over-the-top for being so safety-conscious
"I couldn't believe it when I heard that my four-month-old always slept through the night at my in-laws'," says one mom, a nurse who occasionally works nights and whose husband travels frequently. "Then I found out they were putting Carrie down to sleep on her tummy -- which I know is a huge risk for sudden infant death syndrome. I really flipped out then."
The trick is to be firm without looking like you're accusing your in-laws of deliberately putting their grandkid in danger. As calmly as you can, tell them it makes you feel too uncomfortable when they do things their way. You can say, "I know things were different when you were raising kids, but our doctor insists on [whatever safety measure they're flouting] and we need to be absolutely sure everyone is following her instructions." They may still think it's all overkill, but they're more likely to understand that you're simply following doctor's orders -- not criticizing their ability to take care of a child.

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