A spike in the number of women taking stimulants for attention disorders is raising concern among doctors about the potential impact on pregnancy.

Federal health officials on Thursday reported a 344 percent increase since 2003 in women between the ages of 15 and 44 who filled prescriptions for stimulants and other medications to treat attention deficit/hyperactivity disorder (ADHD). The increase was greatest, 700 percent, among women 25 to 29. The report, by the U.S. Centers for Disease Control and Prevention, covered women with private insurance.

Minnesota doctors said that increase has translated into more patients who are pregnant and have ADHD, which has been challenging because there is no clear medical guidance on whether to keep them on the drugs or not.

“This was not something we saw very commonly among pregnant women 10 years ago,” said Dr. Elizabeth Baldwin, a maternal-fetal specialist with Minnesota Perinatal Physicians.

A few studies have linked stimulants such as Adderall and Ritalin with elevated rates of birth defects, but they aren’t definitive. A study published in the journal Pediatrics last fall, for example, found more seizures among newborns who had been exposed during pregnancy to ADHD medications, but it couldn’t prove that the medications were at fault.

Physicians and their patients need research to address the question because the early stages of pregnancy are key for fetal development, said Coleen Boyle, a CDC specialist on birth defects and developmental disabilities.

“Half of all pregnancies in the United States are unplanned, and women may be taking prescription medicine early in pregnancy before they know they are pregnant,” she said.

Mackenzie Mestelle, a Minneapolis mental health worker, said she struggles to stay on time and plan and cook meals each day — even though she takes ADHD medications. But Mestelle, 29, figures she would quit the drugs anyway if she gets pregnant.

“The goal would be to be off the medication, because it’s not healthy” for the pregnancy, she said.

Most women react that way, Baldwin said, but weaning them off stimulants just because doctors lack risk data isn’t always the best choice if it prevents them from managing their personal health, their families and their jobs.

“If it causes more stress to be off the medication, the question is what’s more harmful — the uncontrolled maternal ADHD or the medication?” she asked.

Alternatives include reducing the dosage or weaning pregnant women off stimulants only during the first trimester, when most fetal organ development takes place.

Some women with ADHD should make the effort during pregnancy to simplify their lives and schedules, regardless of whether they stay on stimulants, said Dr. Elizabeth LaRusso, a psychiatrist who directs mental health care at Allina Health’s Mother Baby Centers.

“I really encourage people to lower their standards, which is something that women who are pregnant, and new moms, need help to do.”

Women can try drugs such as Wellbutrin in place of stimulants to manage ADHD symptoms, she added, but the best approach will be individual to each pregnant woman.

The prevalence of adult ADHD is around 3 to 4 percent. Men are twice as likely to have the disorder, but psychiatrists have found cases in women that went undiagnosed in childhood — because their symptoms involved quiet inattention that went unnoticed by parents and teachers.

Mestelle was not one of those cases. She was diagnosed at age 9. She said she loves her job with the National Alliance on Mental Illness/Minnesota, telling her story to school classes and other groups and working with teens and young adults who have ADHD. Moving beyond structured classrooms and interacting with people was therapeutic in and of itself, she said.

She said she hopes that working with young people will prepare her to be a mom someday. She doubts she will ever be on time, or be good at keeping doctor appointments — but having a child will be motivating.

“I know,” she said, “I’m going to have to become my child’s best advocate.”