NEW YORK (Reuters Health) – Random blood glucose (RBG) measurements early in pregnancy can identify women with overt diabetes in pregnancy (ODIP), researchers from UK report in the August 15th online Diabetes Care.
“Currently, the focus has been on the fasting glucose and HBA1c to look for overt diabetes in pregnancy,” Dr. David Simmons from Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK told Reuters Health by email. “We would like physicians and obstetricians to consider the RBG when they are reviewing their screening policy.”
Dr. Simmons and colleagues tested the usefulness of RBG to detect OCIP in a retrospective analysis of regional hospital obstetric data on 17,852 pregnancies around the initial antenatal visit.
RBG exceeded 7.0 mmol/L (126 mg/dL) in 18.6% of pregnancies, and 12 women without oral glucose tolerance test (OGTT) had RBG of at least 11.1 mmol/L (200 mg/dL). At some point during the pregnancy 3007 women had an antenatal OGTT.
In all analyses, the negative predictive value of a normal RBG for ODIP exceeded 98%.
Depending upon the assumptions, the best RBG cutoffs were 7.31-7.40 mmol/L (132-133 mg/dL)(women without a positive OGTT considered not to have ODIP), 7.51-7.59 mmol/L (135-137 mg/dL)(women with no/incomplete OGTT and an RBG <11.1 mmol/L considered not to have ODIP), and 8.60-8.70 mmol/L (155-157 mg/dL)(among women with both an OGTT and RBG at least 11.1 mmol/L).
“RBG at antenatal booking may provide a sensitive screening tool for the detection of ODIP,” the researchers conclude. “Although the RBG cutoff >7.0 mmol/L was reasonable, we do not feel our retrospective observational data are adequate to recommend changing the RBG action limit to proceed to OGTT.”
“Our findings are particularly important at a time when the diabetes and obesity epidemics are beginning to swamp services, and evidence is growing of the importance of relative maternal hyperglycemia on the neonate in future years, amplifying these epidemics,” Dr. Simmons concluded. “We feel now is the time to take gestational diabetes, including overt diabetes in pregnancy, seriously, including systematic approaches to screening and management.”
“We would expect initial costs and time to increase as women are being followed up and treated for longer-we have been doing this for some time and it is not a large number of women,” Dr. Simmons said. “However, by managing the glucose, potentially undiagnosed diabetes issues (e.g., undiagnosed retinopathy) and obstetric issues from an early time, reductions associated with the costs and time of having a large (or dead) baby, more obstetric intervention (e.g., caesarean section, treatment for pre-eclampsia) and more neonatal intervention (e.g., for neonatal hypoglycemia) are likely to make this a saving overall, but this needs further analysis.”
He added, “Although some women with overt diabetes in pregnancy are not even overweight, a significant proportion are obese and evidence for how we best manage obesity before and during pregnancy is also urgently needed.”
Reference:
Random Blood Glucose Measurement at Antenatal Booking to Screen for Overt Diabetes in Pregnancy
Diabetes Care 15 August 2011.
