A recent study found that developing diabetes later on, after having children, was more likely in women who had pre-eclampsia or gestational diabetes.
Women with either pregnancy complication were twice as likely to develop diabetes later on.
However, the study did not take into account whether the women were obese, so the higher risk of later diabetes could be related to the women's weight.
"Attend all prenatal appointments."
The study, led by Denice S. Feig, an associate professor of medicine and obstetrics & gynecology at the University of Toronto Department of Medicine in Canada, looked at links between certain pregnancy complications and later development of diabetes.
Women who have pre-eclampsia, gestational hypertension and/or gestational diabetes are more likely to have insulin resistance while they are pregnant.
Insulin resistance means that the body does not respond to insulin as it should. Insulin is a hormone that helps metabolize (process) carbohydrates like sugar in your body.
Pre-eclampsia is a pregnancy complication in which a woman has high blood pressure and protein in her urine. The only treatment is to deliver the baby. Gestational hypertension is high blood pressure without protein in the urine.
Gestational diabetes means that a woman develops diabetes while she is pregnant even though she did not have a history of diabetes before pregnancy. For most women, the diabetes goes away after delivering her baby.
The researchers wanted to know if the insulin resistance that can accompany pre-eclampsia or gestational diabetes might increase a woman's risk for developing non-gestational diabetes later.
A little over one million women (a total of 1,010,068) who delivered babies in Ontario between April 1994 and March 2008 were categorized based on whether they had one or more of these conditions or neither.
A total of 22,933 women had pre-eclampsia only while 27,605 had gestational hypertension only and 30,852 had gestational diabetes only.
A total of 1,476 women had both gestational diabetes and pre-eclampsia, and 2,100 women had gestational diabetes and gestational hypertension. The remaining 925,102 women did not have any of these conditions.
The researchers then checked to see how many of the women developed diabetes after having delivered their babies up through March 2011.
The findings revealed that women with pre-eclampsia or gestational diabetes were more likely to develop diabetes than women with neither condition.
Approximately 6.5 out of every 1,000 women per year developed diabetes if they had had pre-eclampsia. Among women who had gestational diabetes, 5.3 of every 1,000 per year developed diabetes after having their child.
The rate of later diabetes among those who did not have gestational diabetes or pre-eclampsia was 2.8 women out of every 1,000 each year.
Having either pre-eclampsia alone or having gestational diabetes alone were calculated to double a woman's risk of developing diabetes in the subsequent 16 years after giving birth.
One significant limitation of the study, however, is that the researchers did not have information on the women's weight, including whether they were obese.
Obesity increases a woman's risk for pre-eclampsia and gestational diabetes, and obesity also increases a person's risk for developing diabetes.
Therefore, it's possible that the higher risk of later diabetes that was linked to pre-eclampsia or gestational diabetes was also related to whether the women were obese.
Kurian Thott, MD, FACOG, an OBGYN at Women's Health and Surgery Center in Washington, DC, said this study was well designed, but it fell short in "looking at variables that can be linked to both pre-eclampsia and gestational diabetes, which is maternal weight, both pre-pregnancy and post-pregnancy."
"Doctors have know for many years that there is a correlation between pre-eclampsia and gestational diabetes, but we also factored in lifestyle, body mass index and pregnancy-related [complications] as part of this diagnostic tree," Dr. Thott said. Body mass index is a ratio of a person's height to weight, used to determine if they are a healthy weight.
"It would be interesting to see if weight gain during pregnancy or being overweight before pregnancy added to this risk," Dr. Thott said. "Knowing this would help doctors counsel women on dietary and exercise regimes before considering getting pregnant. It would also help advise them on the importance of weight loss after pregnancy with one of these complications, as it can help manage their future pregnancy."
It's unclear whether a woman of a normal, healthy weight who had pre-eclampsia or gestational diabetes would also be more likely to develop diabetes later, based on the findings in this study.
The study was published April 16 in the journal PLOS ONE. The research was funded by the Canadian Diabetes Association, the Institute for Clinical Evaluative Sciences and the Canadian Institute of Health Research. The authors declared no conflicts of interest.