CHECKUP\NEWS, TIPS & TRENDS\Pregnancy weight gain reconsidered.

Byline: Daily News Wire Services

Women who follow current guidelines for gaining weight during pregnancy may be packing on more pounds than they need to, according to two obstetricians.

In 1990, new guidelines from the Institute of Medicine increased the recommended weight gain for pregnancy from 20-25 pounds to 25-35 pounds. They also said that women who were underweight should gain 28-40 pounds, and overweight women could gain as little as 15.

The institute based its recommendations on studies showing that inadequate weight gain during pregnancy could cause stillbirth, premature birth or a low-birthweight baby.

But those studies were faulty, incomplete or poorly designed, according to Dr. John W. C. Johnson of the University of Florida College of Medicine in Gainesville and Dr. Michael Yancey of the Tripler Army Medical Center in Honolulu.

Millions of women in the United States were told to gain extra pounds, but "if these recommendations are carried out by patients, they might be more harmful than beneficial," the doctors wrote in the January issue of the American Journal of Obstetrics and Gynecology.

Gaining too much weight during pregnancy is bad for both a woman and her fetus, they said. In the woman, it can cause diabetes, high blood pressure, longer and more difficult labor and an increased risk of Caesarean section. In the fetus, it can lead to an abnormal heart rate or other complications, they warned.

Stroke threat remains: Smokers who kick the habit remain at increased risk of stroke up to 20 years after they quit, a new study shows.

It is well-known that smoking increases a person's risk of suffering a stroke. But some studies have suggested that if a smoker quits, his or her stroke risk returns to that of a nonsmoker within two to four years.

In the new study of 6,500 people, however, those who had not smoked for up to 10 years had a stroke risk similar to that of current smokers - 8 percent suffered a stroke during the 10-year study period, compared to 7 percent of current smokers.

Among people who had not smoked for 11 to 20 years, 6.5 percent had a stroke. And of those who had kicked the habit for more than 20 years, 5 percent suffered a stroke - still higher than the 4 percent of people who had never smoked, Connecticut researchers reported last week at the American Heart Association's Joint Conference on Stroke and Cerebral Circulation.

"The risk of stroke associated with cigarette smoking remains elevated well into the second decade after quitting," said the researchers, led by Dr. Lidgia Vives of the Yale University School of Medicine in New Haven.

"The message from our study is not that smoking cessation isn't worthwhile, but that the benefits may not become apparent during the first 10 years," Vives said.

Smoking has multiple effects on blood vessels and on chemicals produced by blood vessels, according to Vives. For instance, smoking affects the cells that line the blood vessels, causing them to constrict, she said. It also may alter the body's production of prostaglandins, hormonelike fatty acids that play a role in blood-clot formation, the Yale researcher suggested.