The finding comes from analysis of data on more than 175,000 pregnant women treated in Kaiser Permanente hospitals from 1999 through 2005. The researchers focused on the 2,784 births to women who had type 1 or type 2 diabetes at the time they became pregnant. They did not have gestational diabetes, which develops for the first time during pregnancy.
In 1999, eight out of 1,000 births were to women who had type 1 or type 2 diabetes. By 2005, this more than doubled to 18 out of 1,000 births. And this number includes only women who successfully gave birth. Diabetes is a major risk factor for miscarriage, notes study researcher Jean M. Lawrence, MD, MPH, of Kaiser Permanente.
"Type 1 and type 2 diabetes are more dangerous for the baby and potentially harder to treat than gestational diabetes," Lawrence tells WebMD. "It means that diabetes is with you the entire pregnancy -- particularly the crucial early stage of pregnancy, before women even know they are pregnant. At this stage, high blood sugar can cause miscarriage and birth defects."
Nobody knew Sandy Kaplan had diabetes when she had a miscarriage. For most of their 10-year marriage, the 36-year old San Francisco Bay-area woman and her husband have been trying for another pregnancy.
"I was not really working on diabetes control," Kaplan tells WebMD. "I was a very heavyset girl. The doctors all said I just needed to lose weight, but I said, "Yeah yeah yeah, uh-huh, it's the old fat girl thing again."
That changed when Kaplan finally got pregnant for the second time.
"When I got pregnant something snapped in my head. I thought, 'If I really want to have a baby, I need to take care of myself," she says. "So I went to Kaiser, and they got me into a program with a nutritionist. It is really, really hard to lose weight when you are pregnant. I was about 300 pounds -- but I was down to around 230 when I had my daughter."