Uterine contractions and their possible influence on fetal oxygenation.

There is now ample evidence that during uterine contractions the utero-placental blood flow diminishes leading to a temporary decrease of fetal oxygenation. Although the fetus lives at a body temperature of 38 degrees Celsius, the adaptive mechanisms seem to be well attuned to sustain this relative oxygen deprived situation during pregnancy and also during labour. Nevertheless in clinical obstetrical practice the fetus can dy in utero or survive with neurologic handicaps. This is a rare event in term low risk babies with a bodyweight appropriate for gestational age (AGA) in contrast to obstetrical pathology that can jeopardize especially infants small for gestational age (SGA).