Comparison of home glucose monitoring with the oral glucose tolerance test to detect gestational glucose intolerance

Background. Recent evidence suggests that infant morbidity is increased among women who have abnormal prenatal glucose screening tests but who do not have gestational diabetes mellitus (GDM). These women fall into a diagnostic gray zone and historically have not been treated. Methods. Forty-eight pregnant women with abnormal oral glucose challenge test results performed self-monitored blood glucose (SMBG) testing seven times per day for 1 week before undergoing a diagnostic 100-g oral glucose tolerance test (OGTT). At delivery, perinatal complications and birthweights were recorded. Results of SMBG tests for women with normal OGTTs were correlated with infant birthweights. Results. Thirteen infants (37%) were found to be large for gestational age (LGA). Significant correlation was found between increasing birthweight and increasing average fasting SMBG values (P<.001), increasing percentage of SMBG values above 120 mg/dL (6.7 mmol/L) (P<.01), and increasing average SMBG values (P<.016). Conclusions. Maternal home glucose values at 28 weeks correlate with the risk of LGA infant births among women in the diagnostic gray zone. Women with average fasting SMBG values >95 mg/dL (5.3 mmol/L) are at increased risk for giving birth to LGA infants and may be more likely to exhibit complications usually associated with GDM.