Computerized analysis of fetal heart rate after maternal glucose ingestion in normal pregnancy

To examine the effect of maternal oral glucose ingestion on antepartum FHR indices in normal pregnancies at term.

A prospective study was performed on 44 non-laboring healthy women with normal singleton pregnancy at 37-40 weeks gestation. All women had a normal oral glucose tolerance test at 24-28 weeks gestation. FHR was recorded with the Sonicaid Fetal Monitor System (Oxford 8000), for 30 min prior to and 60 min following oral ingestion of 50 g of glucose in the study group of 27 women, and following water ingestion in a control group of 17 women.

All pregnancies had a normal outcome. The maternal blood glucose levels before and 30 and 60 min after glucose ingestion were 70+/-14, 107+/-121, and 106+/-22 mg/dl, respectively (P<0.001). A significant negative correlation was found between the changes in maternal blood glucose levels 30 min after glucose ingestion and the changes in the number of large FHR accelerations at 30 and 60 min after glucose ingestion (r=-0.44, P<0.01 and r=-0.42, P<0.01, respectively). A significant correlation was found between the changes in maternal blood glucose levels 30 min after glucose ingestion and changes in episodes of low FHR variation at this time period (r=0.45, P<0.01). No significant changes in any of the FHR variables were noted in the control group.

In normal pregnancies FHR indices of variation tend to decrease after maternal oral ingestion of glucose.