Gestational Diabetes linked to Chromosomal defici

According to a new study, researchers, suggest that, some women who develop gestational diabetes during pregnancy may be prone to have children with certain chromosomal abnormalities However, researchers stress, gestational diabetes is not itself a risk factor for these types of defects since they form in the early stages of pregnancy--well before gestational diabetes typically develops.

The authors of this study speculate that gestational diabetes may, in some women, signal pre-existing factors--such as a propensity for abnormal immune responses that boost the chances of certain chromosomal abnormalities in their children.

Dr. Lynn Moore, of Boston University School of Medicine in Massachusetts, in her report said that, she looked at data on more than 6,500 pregnant women who underwent amniocentesis to detect chromosomal abnormalities in a US study in the 1990s. Those who gave birth were then followed for one year.

The investigators found that women who developed gestational diabetes were twice as likely to have children with chromosomal defects--a prevalence of just over 4%, compared with roughly 2% among women without gestational diabetes. The increased risk was specifically for defects of the sex chromosomes, particularly anomalies in which the child had an extra X chromosome.

In boys, this extra X can result in Klinefelter's syndrome, which is marked by features like small testicles and later infertility. However, many males with an extra X are never even aware of it. In girls, the extra X is known as triple-X syndrome, but it, too, often creates no apparent problems.

According to Moore and her colleagues, their findings support the theory that some women who develop gestational diabetes may have "underlying biochemical changes" that promote the development of chromosome defects before the diabetes is ever apparent.

By definition, gestational diabetes appears during pregnancy. Like other forms of diabetes, it is marked by the body's inability to properly use the blood sugar-regulating hormone insulin. For most women, the condition goes away after giving birth.

However, Moore's team points out, for some women gestational diabetes signals an increased risk of developing type 2 diabetes. For others, it may be precursor to type 1 diabetes, a form of the disease caused by an abnormal immune system attack on the body's insulin-producing cells. The researchers speculate that some women with gestational diabetes may have underlying immune system dysfunction or other anomalies that could affect fetal development. They call for more research into the possibility.