medwireNews: Impaired awareness of hypoglycemia (IAH) is associated with an increased risk for severe hypoglycemia and increased fear of hypoglycemia (FOH) in pregnant women with type 1 diabetes, shows a post-hoc analysis of CONCEPTT data.
The findings, reported at the virtual ADA 80th Scientific Sessions, also showed that increased FOH was associated with an increased risk for maternal nephropathy but a decreased risk for neonatal complications.
Presenting author Jasmine Bahrami, from McMaster University in Hamilton, Ontario, Canada, described this latter association as “very reassuring.”
She said: “We think that the results of our study could be used to give reassurance to many of these women that have impaired awareness [of hypoglycemia] especially in the first trimester.”
Among the 214 women included in the analysis, 64 (30%) had IAH – defined as being sometimes or never aware of hypoglycemia – at baseline.
These women had significantly more episodes of severe hypoglycemia during pregnancy than the 150 women with normal hypoglycemia awareness, at a mean of 0.44 versus 0.08. They were also significantly more likely to have a higher standard deviation of glucose levels and coefficient of variation at baseline and spent a greater proportion of time below range (<63 mg/dL; 3.5 mmol/L) at 12 weeks gestation (10.4 vs 8.0% of time).
There was no difference in neonatal outcomes between the women with IAH and normal awareness, but women with IAH scored significantly higher on the worry scale of the Hypoglycemia Fear Survey (HFS)-II than those without (mean 25.9 vs 20.2 points).
And further analysis showed that higher HFS-II scores were associated with a significant 74% increased risk for severe maternal hypoglycemia and a 91% increased risk for nephropathy, but a significant 40% lower risk for neonatal hypoglycemia.
Bahrami said that the reduced neonatal hypoglycemia risk was an “unexpected finding,” the reasons for which “are currently not known.”
She also noted that the use of continuous glucose monitoring (CGM), which was being compared with standard capillary glucose monitoring, in CONCEPTT did not affect the incidence of severe hypoglycemia.
Another study looking at CGM use during pregnancy, reported as a late-breaking poster by Ravinder Jeet Kaur, from the Mayo Clinic in Rochester, Minnesota, USA, found that one of the 22 participants experienced severe hypoglycemia during the study, giving an incidence rate of 7 cases per 100 patient–years.
The percentage of time spent in biochemical hypoglycemia ranged from 2.8–4.0% at a cutoff of 63 mg/dL (3.5 mmol/L) and 0.9–1.6% at a cutoff of 54 mg/dL (3.0 mmol/L), with the greatest percentage of time observed during the first trimester.
In addition, five (22.7%) women experienced prolonged hypoglycemia (<54 mg/dL for ≥120 minutes) during the study. There were nineteen prolonged hypoglycemia events in total, 11 of which occurred in one individual, with the majority (84%) recorded overnight (6am–12am).
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