Fetal Risk: Inflammation in womb tied to cerebral palsy
By Nathan Seppa
For a woman who has carried her baby to term, inflammation of the uterine lining or the membrane surrounding the fetus nearly quadruples the chance that her baby will be born with cerebral palsy, a new study finds. Cerebral palsy normally strikes 1 or 2 children per 1,000 born after full-term pregnancies.
Yvonne W. Wu, a pediatric neurologist at the University of California, San Francisco and her colleagues identified 109 children at least 2 years old with moderate to severe cerebral palsy. As a comparison group, the doctors also studied 218 babies without the condition.
A review of records showed that 14 percent of the cerebral palsy infants had been born to women diagnosed with an inflammation of the uterine lining or fetal membrane shortly before or after giving birth, compared with only 4 percent of the healthy infants in the comparison group, the researchers report in the Nov. 26 Journal of the American Medical Association.
Doctors identify such inflammation, which usually indicates infection, by checking for fever, abdominal tenderness, and fluid discharge from the vagina. In the new study, the researchers found that 20 percent of the cerebral palsy infants’ mothers had fevers during labor or birth, compared with only 7 percent of the control group.
Although the cause of cerebral palsy is unknown in most cases, a lack of oxygen to a fetus has long been the chief suspect. Such asphyxia could result in brain injury in which motor coordination is lost.
But earlier research led Wu and her colleagues to suspect that inflammation plays a roll as well. Those studies turned up high concentrations of inflammatory molecules called cytokines in the blood of infants later diagnosed with cerebral palsy (SN: 10/17/98, p. 244: https://www.sciencenews.org/sn_arc98/10_17_98/Fob1.htm).
The inscrutable origin of cerebral palsy suggests that a combination of factors is at work, says Karin B. Nelson, a pediatric neurologist at the National Institute of Neurological Disorders and Stroke in Bethesda, Md. “Things that cause rip-roaring infections are usually not what cause [cerebral palsy], or we’d have known it by now,” she says. But a subtle infection, together with a clotting abnormality or a period of low oxygen in the womb, “could zap a fetus that might have been robust enough to withstand any one of these,” she says.
Indeed, inflammatory proteins might interact with clotting factors–which are abundant in pregnant women–in some way that leads to brain damage, Wu and her colleagues hypothesize. Magnetic resonance imaging in the new study showed that many babies with cerebral palsy had brain damage similar to that seen after strokes, Wu notes.
This and the previous work should change how doctors treat pregnant women who show warning signs of inflammation in the womb, says Larry C. Gilstrap, an obstetric gynecologist at the University of Texas Health Science Center at Houston. Any pregnant woman with an infection of the fetal membrane or uterus, or whose “water breaks”–meaning the membrane has ruptured–should be treated promptly with antibiotics or induced to deliver if she is close to term, he says.
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