More American women are entering pregnancy with diabetes, a troubling trend that means health risks for both mothers and newborns, U.S. researchers said on Monday as quoted by media reports.

The rates of diabetes before motherhood increased the greatest among 13- to 19-year-olds giving birth. It ballooned from about 1 per 1,000 pregnancies to 5.5 per 1,000 during the seven-year period.

Having diabetes before pregnancy poses a particular risk because it affects the developing fetus right from the start, researchers said.

Expectant mothers who don't control their diabetes face an increased risk of miscarriage and stillbirth. Their babies have a higher chance of being born with birth defects.

"It is really important for women with diabetes to plan their pregnancies and seek advice from their healthcare provider before they become pregnant," said Dr. Jean Lawrence of healthcare provider Kaiser Permanente in Pasadena, California, whose study appears online Monday in the journal Diabetes Care.

Past studies have looked at the rate of gestational diabetes, a type of diabetes that typically develops in the second trimester of pregnancy and often goes away after a woman gives birth.

Blacks, Asians and Hispanics were more likely to have diabetes before pregnancy than whites.

Researchers suggested women control blood sugar levels with an insulin pump or maintain a healthy diet and exercise routine, which will increase the likelihood of them having a healthy baby.

Overweight women are also encouraged to shed some pounds before getting pregnant.

The North Shore-Long Island Jewish Health System in New York has a special program to help moms-to-be manage their diabetes.

Women are encouraged to seek medical help at least three months before they plan to have a baby so doctors can help them control their blood sugar and increase their intake of folic acid.

(Agencies/Xinhua News Agency April 28,2008)