Caution was the watchword for Grace Montoya’s first pregnancy eight years ago.

The Valencia, Calif., resident had been diagnosed with type 1 diabetes when she was a teenager. As a registered nurse trained in pregnancy and diabetic care, she knew her pregnancy would have to be closely managed. She tested her blood eight to 10 times a day, ate six small meals and snacks to stabilize her blood sugar, watched her weight and saw a doctor almost every two weeks in the first half of the pregnancy.

“It was a lot of hard work,” she says. “… But being in the health profession, I knew what could happen with my health and my baby’s health if I wasn’t careful.”

Her son was born healthy.

More women than ever are experiencing the conflicting worlds of pregnancy and diabetes. A study from Kaiser Permanente published in April found that births to women with diabetes doubled between 1999 and 2005.

Now some health experts are proposing that teenagers and young women who are diabetic or are at risk of becoming diabetic should be counseled about pregnancy.

“We’re seeing children as young as 10 developing type 2 diabetes,” said Jean Lawrence, the lead author of the study and a research scientist at Kaiser Permanente’s Department of Research and Evaluation. “That means it’s never too early for young women to know about their health as it relates to future childbearing.”

Pregnant women with diabetes are at greater risk of suffering a miscarriage or stillbirth. Babies born to diabetic mothers are at higher risk of being premature and having birth defects. And a growing body of research suggests that babies born to diabetic mothers have an increased risk of becoming overweight or developing diabetes themselves.

Kaiser scientists found the rates of preexisting diabetes in pregnant women rose from 8 per 1,000 in 1999 to 18 per 1,000 in 2005. The rate increased the greatest among teens ages 13 to 19 — a fivefold jump over the seven years of the study. The study sampled 175,000 ethnically diverse women who gave birth in Kaiser hospitals.

The widespread trend toward obesity among all age groups is most likely to blame for the shift, Lawrence says.

Preconception care has been recommended to U.S. women for almost 20 years. But federal, state and local governments have focused largely on ensuring medical care for women who are already pregnant, says Dr. Peter Bernstein, a maternal-fetal medicine specialist in New York City.

“But with all those programs, what we found is that the number of preterm births and number of low birth-weight babies is going up, not going down,” he says. “That got people thinking about ‘Is prenatal care making a difference?’”

Some maternal- and fetal-health experts suggest that focusing on good health care for reproductive-age women before pregnancy may yield bigger benefits.