Maternal Pre-Existing Diabetes Nearly Doubles Risk of Infant Death

Babies are significantly more likely to die in pregnant women with pre-existing diabetes than when the mother does not have the disease, according to research published in Diabetologia.

Infant deaths nearly doubled (RR, 1.86; 95% CI, 1.00, 3.46; P = 0.046) in women with pre-existing diabetes, when compared with those without the disease. The comparison, however, was even more pronounced when fetal deaths were examined. Unborn fetuses were 4.5 times more likely to die if the mother had pre-existing diabetes, according to the research (RR, 4.56; 95% CI, 3.42, 6.07; P < 0.0001).

The prevalence of fetal death was 3% in women with pre-existing diabetes compared with 0.7% in women without the condition. For infant deaths, the prevalence in mothers with diabetes was 0.7%, compared with 0.4%.

The study, by researchers from Newcastle University, United Kingdom, the South Tees NHS Trust, United Kingdom, and Public Health England, used several long-standing population-based registers in the north of England to identify singleton offspring of women with both type 1 and type 2 diabetes mellitus (1,206 type 1 and 342 type 2 diabetes mellitus).

While previous research has looked at the relationship between maternal pre-existing diabetes and baby deaths, the authors said this latest study is the first to exclude babies with congenital anomalies.

In analyzing the data, the researchers found that women with diabetes who had a glycosylated hemoglobin concentration above 6.6%, those with pre-pregnancy retinopathy, or those with a lack of folic acid supplementation were all at greater risk for experiencing a fetal or infant death. On average, the glycosylated hemoglobin concentration in the pregnant women analyzed by the study was 7.8%. Meeting the American Diabetes Association’s target of 7% would have lowered the fetal and infant death prevalence by about 40%, the authors estimated.

In addition, the authors noted that there was no evidence to support that the risk of infant or fetal death in mothers with pre-existing diabetes had improved over time.

"It's disappointing to see so little improvement because, with the right care, most women with diabetes can-and will-have a healthy baby,” the authors said in a statement. “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.”

The authors suggested the high-dose folic acid supplement taken prior to conception that is already proven to reduce risks of spina bifida may also reduce stillbirth and infant death. The study, however, did not examine proven ways of reducing the risk factor.

Pertinent Points:
- Stillbirths are 4.5 times more likely in women with pre-existing diabetes than in women who don’t have the condition.
- Infant deaths nearly doubled when the mother had diabetes prior to conception.
- There was no evidence that the risk of infant or fetal death in mothers with pre-existing diabetes had improved over time.

References:

Reference

Tennant PWG, Glinianaia SV, Bilous RW, et al. Pre-existing diabetes, maternal glycated haemoglobin, and the risks of fetal and infant death: a population-based study.

Diabetologia.

2013 Nov 29. [Epub ahead of print]