A reduction in fetal, neonatal and perinatal death rates by approx 50% over the last 15 years has occured. A similar reduction in the rate of children born with CP would have been expected. Not so, thus conclusion is that most causes of CP occur in the womb.

CP is higher in preterm infants. For pregnancies <33 weeks gestation, rate is 30 times greater than for babies born at term. The more preterm the birth the higher the rate. Approx 50% of cases of CP occur in infants born preterm. Avoiding preterm delivery or lengthing the pregnancy should reduce occurences of CP.
It was thought that chorioamnionitis, prolonged rupture of membranes and maternal infection were risk factors. Research by Gray et al 2000 has shown that choriomnionitis has been disproved to be associated with CP, and showed the main predictors were Intra Uterine Growth Restriction (IUGR) and absence of antenatal steroids. In this study, maternal hypertension was shown to be a safe guard against CP, a suprising discovery, the reasons being unknown. Mothers given corticosteroids have pregnancies lengthened. Those who remain undelivered after one treatment benifited further from multiple treatments. Also a reduction in incidences of CP was recorded in these births.

Multiple pregancies are associated with an increase in CP. For twins the risk is 5 times greater than singletons and triplets -18 times. Rates of multiple pregnancy are increasing because of increasing maternal age and development of artificial reproductive technology.
For twins, the greater risk is in same sex monochrionic twins. This may be explained by the fact that twin to twin transfusion syndrome occurs predominantly in this group. The degree of twin-twin transfusion can vary condiserably. Laser fusing of the blood vessels causing the transfusion is being trialed but results are still in their infancy.

The use of magnsium sulphate given for neuroprotection before preterm birth has been studied and five studies have shown a significant statistical improvement in reducing brain injury, including cerebral palsy. Prospects for this intervention look good and more studies are in progress.

The use of hypothermia for neonatal encephalopathy (cooling the head in cases of possible brain injury) was discussed as having some promise, but again, results were still being accumulated.

The overall conclusion of the presentation; use of magnesium sulphate for preterm infants has significant prospects and cooling may be effective for infants born at term in a depressed condition. Without further reasearch the prospects for reducing the number of birth involving CP were very slight.

So it looks like for the foreseeable future the 2 to 2.5/1000 births will still involve some form of cerebral palsy.

Harvey Brunt- General Manager CP Society