Umbilical cord blood gases: routine measurement may exonerate ob.gyns.(Obstetrics)

PHILADELPHIA -- The routine measurement of umbilical cord blood gases after every delivery could help answer questions about the possibility of birth asphyxia a few years after the fact, often exonerating obstetricians, Dr. Gary D.V. Hankins said at the annual meeting of the American College of Obstetricians and Gynecologists.

Dr. Hankins chaired the task force that released the 2003 report "Neonatal Encephalopathy and Cerebral Palsy: Defining the Pathogenesis and Pathophysiology,"--a joint effort by ACOG and the American Academy of Pediatrics. The report shifts much of the blame for cerebral palsy (CP) away from obstetricians, suggesting that antepartum events are the major cause.

In fact, published data from which the task force drew heavily in its report suggest that 69% of cases of neonatal encephalopathy (NE) and CP were linked to antepartum risk factors alone, 4% were linked to intrapartum hypoxia, and 25% were linked to a combination of antepartum risk factors and intrapartum hypoxia. The rest of the cases had unknown causes (BMJ 317[7172]:1549-53 and 1554-58, 1998).

The same study also found that while an acute intrapartum event conferred a fourfold increased risk for NE and CP, similar risk was conferred by preconceptual or antepartum factors such as infertility treatment (odds ratio 4.43) and occipitoposterior fetal position (OR 4.29). Maternal factors such as treated or untreated thyroid disease also conferred risk (OR 9.7), as did a family history of seizures or neurologic disorders (OR 2.55 and 2.73, respectively).

"We have not made advances toward reducing rates of CP, because most of the causes of CP are remote from labor," he told a packed house at the meeting.

Dr. Hankins said that following the birth of a baby with CP, there are many factors that are beyond obstetricians' control in the cascade of events that spiral toward ...