Jill is pregnant and loves fish, which she has eaten almost daily for years as part of her effort to stay healthy. She hears that fish should not be eaten regularly during pregnancy. Why, she wonders,...

Jill is pregnant and loves fish, which she has eaten almost daily for years as part of her effort to stay healthy. She hears that fish should not be eaten regularly during pregnancy. Why, she wonders, should I cut down on eating something as healthy as fish?