Objective: To assess the relationship between subsequent neuro-development and measurements in small for gestational age (SGA) fetuses, including oxygenation at cordocentesis.
Design: A longitudinal study of a cohort of SGA fetuses using those with normal oxygenation as controls.
Subjects: 65 chromosomally normal children aged 12-66 months who, as fetuses, had been small for gestational age, had undergone cordocentesis and had been delivered after 32 weeks' gestation.
Results: Griffiths' developmental quotient (DQ) was significantly associated with fetal blood pH (r = 0.41, P = 0.0008), PO2 (r = 0.25, P = 0.047) and PCO2 (r = -0.28, P = 0.027) at cordocentesis but not with the severity of growth retardation (r = 0.18, P = 0.17). However, the significant correlations between DQ and both PO2 and PCO2 were explained by their co-correlations with pH and neither remained significant after removing the effect of pH by analysis of variance. The association between DQ and pH was still significant after removing the effect of confounding variables. Maternal smoking during pregnancy was significantly associated with DQ (F to remove = 6.89, P = 0.011) even after allowing for the effects of possible confounding variables including fetal blood pH.
Conclusions: Both fetal pH at cordocentesis and maternal smoking correlate significantly with subsequent neuro-development. Further investigation into the causes of these associations is required.