Objective: To study the relations between different types of acidemia in umbilical artery at birth, fetal heart rate patter'ns (FHR) during laobr and infant long-term outcome.
Methods: 2,981 cases with singleton term pregnancy were selected for retrospective case-control study. Fetal monitoring was performed periodically during labor and umbilical blood gas was analyzed at birth and the infants outcome was followed up at age 4.
Results: There were 47 infants with pure metabolic acidemia and 67 infants with mixed acidemia. The incidence of FHR score < 6 and 6-7 at the end of first stage was significantly higher in the two study groups than that in the control group. Late deceleration was associated with pure metabolic acidemia and complicated variable deceleration with mixed acidemia. Both types of acidemia were correlated with Apgar scores below 7 at 1 minute after birth. Developmental screening at age 4 showed no significant differences between the two study groups and the control groups. In the mixed acidemia group there were slightly more infants had deficits in speech/language development.
Conclusions: Late deceleration may be an indicator of pure metabolic acidemia and complicated variable deceleration be an indicator of mixed acidemia. Both types of acidemia were correlated with Apgar scores below 7 at 1 minute after birth. The relation between acidemia at birth and deficit in speech/language development should be further evaluated.