High maternal blood sugar levels and BMI are risk factors for stillbirth in mothers with diabetes, according to a new study in Diabetologia (the journal of the European Association for the Study of Diabetes), with babies at the lowest and highest weights being most at risk. Mothers with pre-pregnancy diabetes are at a four to five times increased risk of stillbirth - with no improvement seen over recent years, in contrast with decreasing stillbirth rates seen in the general obstetric population.
Furthermore, the level of the mother’s blood sugar emerged as a key risk factor for increased risk of stillbirth. Overall, while one third of stillbirths in mothers with diabetes occur close to term and might be influenced by policy on delivery, the majority occur before 37 weeks and finding better ways of detecting babies at risk will be critical.
Maternal obesity, advanced maternal age and smoking are known to be important modifiable risk factors for stillbirth in the general population, as is restricted fetal growth.
However, data on pregnancies complicated by diabetes are more limited. Previous studies have indicated that suboptimal maternal blood glucose levels, microvascular complications and poor preparation for pregnancy are associated with stillbirth in mothers with diabetes - however traditional risk factors noted in the general population are less well documented for mothers with the condition.
This study, of over 5,000 infants over 18 years, considering a range of potential risk factors, has clearly shown that maternal blood sugar levels and BMI are the main modifiable risk factors associated with stillbirth in women with diabetes. Mortality rates are highest for infants born small for their gestational age, but large infants are also at increased risk.