Pregnant women with pre-existing diabetes have almost a four and-a-half time’s greater risk.
Past studies have found that pre-existing diabetes is associated with an increased risk of stillbirth but few studies have excluded the effect of congenital anomalies.
In this new study Dr. Ruth Bell, MD, MSc, Senior Lecturer and Honorary NHS Consultant and Peter Tennant, Research Associate, Epidemiology, Newcastle University and colleagues from Newcastle University, and the South Tees NHS Trust, UK and Public Health England, examined the link between pre-existing diabetes and the risks of fetal and infant death in offspring without congenital anomalies.
For this study, researchers used data from a long-standing population-based survey of women with pre-existing diabetes.
All normally-formed singleton offspring occurring in women with pre-existing diabetes (1,206 with type 1 diabetes and 342 with type 2 diabetes) in the North of England during 1996-2008 were identified from the Northern Diabetes in Pregnancy Survey.
Researchers compared data from the Northern Perinatal Morbidity and Mortality Survey to estimate the relative risk of still birth, defined as death of a fetus at or after 20 weeks’ gestation and infant death, defined as death in the first year of an infant’s life.
The results of the analysis had found that women with pre-existing diabetes were four times greater (4.56) to have a still birth compared to women without diabetes, while for infant death the risk was almost double (1.86). There was no difference in the prevalence of fetal death or infant death between women with type 1 diabetes and women with type 2 diabetes. Women with glycated haemoglobin (a standard measure of blood sugar control) above 6.6%, those with pre-pregnancy retinopathy (a complication of diabetes) and a lack of folic acid supplementation were all independently associated with increased odds of fetal and infant death.
The average glycated haemoglobin level in the pregnant women studied was 7.8%. England’s National institute for Health and Care Excellence (NICE), has set a target of 6.1% for women, while the American Diabetes Association target is 7%. ‘If the women in the study had all achieved either the ADA target or NICE target, the authors estimate the prevalence of fetal death and infant death would have been around 40% lower.
In their conclusion the researchers write “Pre-existing diabetes is associated with a substantially increased risk of fetal and infant death in normally-formed offspring, the effect of which is largely moderated by glycemic control.”
The authors commented “It’s disappointing to see so little improvement because, with the right care, most women with diabetes can — and will — have a healthy baby. Stillbirths and infant deaths are thankfully not common, but they could be even less common if all women with diabetes can be helped to achieve the best possible control of their blood glucose levels.”
“We already know that folic acid reduces the risk of certain congenital anomalies, such as spina bifida or cleft lip, which is why women with diabetes are advised to take high dose supplements of 5 milligrams daily. These are available on prescription and should be taken for at least 3 months before conceiving. Our results suggest this simple action may also help to reduce the risk of stillbirth or infant death even in babies without these conditions.”
In conclusion they comment “If you are planning a pregnancy, and your blood glucose levels are high, then any reduction, even a small one, is likely to be good for your baby. Secondly, seek advice as early as possible from your diabetes team. They can help you keep your glucose at safe levels, as neither high blood glucose nor repeated episodes of severe hypoglycemia are good for you or your baby.”
This new research is published in published in Diabetologia.
