Relationships between umbilical cord arterial blood pH levels at delivery and Bayley Psychomotor Development Index scores in early childhood.
AIMS
To correlate data on umbilical cord arterial blood pH (pHa) levels obtained at delivery with subsequent Bayley Psychomotor Development (PDI) scores determined on the same cohort of children at age 18 months.


METHODS
At delivery, we obtained umbilical cord bloods for pHa levels along with other biological parameters. Following the birth cohort prospectively, at age 18 months we did a comprehensive, blinded neurodevelopmental examination to determine a PDI score for each child.


RESULTS
Over the broad range of umbilical cord arterial blood pH levels from 7.03 to 7.52, no statistically significant correlation (Pearson correlation coefficient, -0.016, P=0.88) was found between pHa at delivery and PDI scores at age 18 months. To study our finding in greater detail, we formed a subset of the data consisting only of lower pHa levels at delivery (defined as <or=7.20) and subsequent PDI scores. In this data subset, we again found that no significant relationship existed (Pearson correlation coefficient, +0.003, P=0.99).


CONCLUSIONS
Our findings are consistent with the evolving hypothesis that adverse neurological outcomes in children often have etiologies other than intrapartum fetal acidemia.