Abstract
Objective
A low 1-hour glucose challenge test (GCT) result (<10th percentile for population)
has been associated with neonatal morbidity, including small-for-gestational-age birth
weight, and it is hypothesized that underlying maternal hypoglycemia may contribute
to this neonatal morbidity. We sought to assess whether eligible patients would undergo
continuous glucose monitoring to allow comparison of maternal hypoglycemia between
those with a low GCT result versus controls.
Study Design
This exploratory study enrolled patients who completed a GCT between 24 and 30 weeks'
gestation from June to September 2022. English- or Spanish-speaking participants aged
≥18 years wore a blinded continuous glucose monitor (CGM) for 10 days. There were
10 participants each in the low GCT (<82 mg/dL) and normal GCT group. Proportions
were calculated to determine recruitment rates and describe the low versus normal
glycemic groups across clinical and sociodemographic characteristics. Maternal hypoglycemia,
defined using various proposed thresholds, was analyzed as continuous data (time duration)
with Student's t -tests and categorical data (number of episodes) with chi-square tests and bivariate
analyses were performed comparing participants with a low versus normal GCT. Primary
outcome measures were recruitment, enrollment, and adherence rates, and overall glycemic
values for each group.
Results
Of 64 eligible patients, 58 (91%) were approached, and of them, 20 (35%) were enrolled.
All 20 participants had CGM data to review with 100% adherence. Average glucose values
were similar between participants in the low GCT and normal GCT groups (111.7 ± 18.0
vs. 111.6 ± 11.7 mg/dL, p = 0.99), and participants with a low GCT value did not demonstrate more hypoglycemia
than those with a normal GCT value across five proposed thresholds on CGM analysis.
Conclusion
In this pilot study, participants wore blinded CGMs to collect glycemic data, and
those with a low GCT result did not experience more hypoglycemia than those with a
normal GCT on CGM analysis.
Key Points
Study participants wore continuous glucose monitors in blinded mode to gather glycemic
data with 100% adherence.
Participants with a low GCT result (<82 mg/dL) as compared with those with a normal
GCT result were not more likely to demonstrate maternal hypoglycemia using several
thresholds on CGM analysis.
In our cohort, there were few participants in either glycemic group who reported food
insecurity or lived in a food desert.
Keywords maternal hypoglycemia - neonatal morbidity - continuous glucose monitoring
