ALMOST ONE in 10 Irish women develops diabetes during pregnancy, while 80 per cent of these are overweight or obese, new research has found. Blood tests carried out on 3,500 pregnant women attending five hospitals in the Republic have revealed that 9.3 per cent have gestational diabetes mellitus (GDM).
The recently completed second phase of the diabetes in pregnancy study (Atlantic - DIP), funded by the Health Research Board (HRB), examined 13,257 deliveries at five hospitals along the Atlantic seaboard between February 2007 and September 2008.
Women who took part in the National University of Ireland Galway (NUIG) study were tested for diabetes between the 24th and 28th week of pregnancy using an oral glucose tolerance test (OGTT). After being given 75g of glucose, blood tests were taken to see whether sugar levels remained within normal limits.
A positive OGTT means the woman has GDM, which may have short- and long-term health consequences for both the mother and her baby. GDM disappears in most women after they give birth.
Babies born to mothers with GDM tend to be much heavier and have an increased risk of death in the womb. Mothers are more likely to need a Caesarean section and to suffer pregnancy-related high blood pressure.
Later in life, infants born to mothers with GDM are themselves more likely to have diabetes and to be obese. Mothers with GDM have a higher life-time risk of developing full-blown diabetes.
The Atlantic-DIP study, led by Dr Fidelma Dunne, consultant endocrinologist at University Hospital Galway (UHG), found a doubling of pregnancy-induced hypertension in the women with GDM compared with those with a normal tolerance for glucose.
Some good news to emerge from the research was that the early identification and treatment of women with gestational diabetes led to their babies having normal birth weights. Some 60 per cent of women responded to diet and exercise, while others required insulin treatment as well.
"Identification of GDM women allows identification of an 'at-risk' population for future diabetes and heart disease where intervention is likely to make an impact," the report's authors say.
Asked if the results meant there was a need to introduce screening for diabetes for all pregnant women in the State, Dr Dunne said: "if you do not offer universal screening you are likely to miss half of women with GDM".
While acknowledging a national screening programme would be both time consuming and logistically challenging, Dr Dunne said a combined community and hospital approach would make the programme feasible.
Earlier this year the first stage of the Atlantic-DIP study found that Irish women with pre-existing diabetes were poorly prepared for pregnancy and their babies were more likely to die than those born to women without the disease.
With the aim of profiling the quality of care and pregnancy outcomes of mothers with diabetes, this study of women attending hospitals in Letterkenny, Sligo, Ballinasloe, Castlebar and Galway found the still-birth rate for babies of mothers with diabetes was seven times that of other mothers in the west of Ireland.