‘90s FAMILY : Baby Books Grow Up and Meet the ‘90s : Today’s guidelines speak to both parents. And while some advice remains the same, those old rules about alcohol, smoking and moms working outside the home sure have changed.

Once upon a time, before amniocentesis, ultrasound and fetal monitoring, pregnancy was full of uncertainties. Women listened closely to their mothers and doctors, and perhaps read a good baby book.

In the past 25 years, conventional wisdom on prenatal and child care has been changed more times than a newborn’s diaper. And, to keep up, baby books have grown up.

What was once a guide for new mothers is now a book for moms and dads, who both are likely to work outside the home and share child-care duties.

A comparison of the “Better Homes and Gardens Baby Book” from 1969 and the updated 1991 printing reveals some funny yet startling changes that have occurred since many of today’s moms were babies.

Some of the basic old advice holds true, such as the importance of maintaining a healthful diet, but much of what was permitted is now on a long list of no-nos.

“If you’re a heavy smoker,” the 1969 version says, “doctors advise that you cut down to a great extent, but you needn’t quit entirely, unless your doctor recommends it.”

Now, women who smoke are warned that they run an increased risk of having an underweight baby. Heavy smokers increase their risk of stillbirth. Even exposure to secondhand smoke is seen as a threat to the unborn child.

Alcohol was once considered a danger only to a woman’s waistline.

“Alcoholic beverages contain between 70 and 160 calories,” the old edition warns, “and might be worth eliminating from your diet if the doctor suggests cutting down on your caloric intake.”

Now, studies have shown that babies born to alcoholic mothers commonly suffer from fetal alcohol syndrome. These children are undersized, have a characteristic facial appearance and low IQs. Moderate drinking is also thought to affect the unborn child.

Despite the growing number of restrictions, the rules concerning women working outside the home have relaxed.

The 1969 version says: “Unless it is absolutely necessary for you to work, think it over carefully before you leave your baby in the care of someone else every day. He needs you!”

Women who worked during pregnancy were advised to stop when they began showing in the fifth month. And, certainly they should stop after the seventh month. Now, many doctors consider working during pregnancy vital to a woman’s emotional health.