The rate of cerebral palsy among very preterm infants may be much lower now than 20 years ago, a single-centre study suggests.
Researchers at the University Medical Centre Utrecht in The Netherlands found that between 1990 and 2005, cerebral palsy rates fell among preterm infants treated in their neonatal intensive care unit (NICU).
From 1990 to 1993, 6.5% of 755 infants admitted to the NICU were diagnosed with cerebral palsy. That rate fell to 2.2% of 913 newborns between 2002 and 2005, they reported in The Journal of Paediatrics.
Decline in cerebral palsy
It's not clear why some past studies have failed to show a decline in cerebral palsy. One reason may be that some have included the most extreme preemies, born during the 23rd or 24th week of pregnancy. The infants in the current study were born at week 25 or later.
Much of the decline in the current study seemed to be related to a 93% drop in the number of preterm infants with severe damage to the cystic per ventricular leukomalacia (i.e., the white matter of the brain). The condition is commonly caused by infections in the mother.
In general, the researchers say, improvements in prenatal care likely deserve the credit for the declining rate of cerebral palsy. Giving antibiotics to mothers in preterm labour was one such factor, lead researcher Dr Linda de Vries said.
Another was giving corticosteroids to mothers who are at risk of pre-term labour, to speed foetal lung development.
"Over the years we have seen a decline in the number of infants needing ventilation after delivery," Dr de Vries said. And as fewer preemies have needed to be placed on ventilators, fewer have been developing brain damage resulting in cerebral palsy.
The findings are "indeed good news," she said.
While the findings are from one medical centre, Dr de Vries said there's similar evidence from other developed countries. A recent Canadian study found a declining prevalence of cerebral palsy over 30 years, she noted. And a study at the University of California, San Francisco, found a falling rate of cystic per ventricular leukomalacia after the early 1990s.
A US study published last month highlighted the importance of preterm birth - and possibly prenatal care - in children's risk of cerebral palsy.
The overall prevalence of cerebral palsy was 1.4 cases for every 1,000 live births.
The researchers speculated that better prenatal care for mothers, especially teenagers, might help close the racial gap in low birth weight - and possibly cerebral palsy as well. (Reuters Health/ March 2011)