Human fetal breathing response to intravenous glucose is directly related to gestational age.

This prospective longitudinal study examined human fetal breathing activity over the second half of pregnancy both in the fasting state and after intravenous glucose administration. There was a linear relationship between gestational age and percent time spent breathing after glucose between 19 and 38 weeks' gestation. However, no such correlation could be demonstrated between gestational age and fetal breathing activity in the fasting state.