The small-for-gestational-age fetus has an intact ability to develop lacticemia when exposed to hypoxia: a retrospective comparative register study

Objective: To investigate the ability of small-for-gestational-age (SGA) fetuses to develop lacticemia during hypoxia.
Methods: Umbilical cord arterial and venous pH, lactate and glucose concentrations were determined in 1777 SGA (<10th percentile) and 14,569 AGA newborns and related to acidemia (pH < mean –2SD). Non-parametric statistics with two-sided p < .05 were considered significant.
Results: Glucose and lactate were linearly related and both variables correlated negatively with pH. Glucose was equal in SGA and AGA at a normal pH, but at severe acidemia it was lower in SGA. Glucose was higher in both groups during acidemia. Lactate was higher in SGA at both a normal and a low pH, and in both groups lactate increased progressively with the severity of acidemia.
Conclusions: In both SGA and AGA fetuses, glucose was mobilized during acidemia; lactate was higher in SGA at both a normal and low pH. Considering SGA being a proxy for fetal growth restriction, and acidemia a proxy for hypoxia, it is concluded that growth-restricted fetuses have an intact ability to develop lacticemia during hypoxia.