Editing Cerebral palsy (section)

===Preterm birth===
Between 40% and 50% of all children who develop cerebral palsy were born prematurely.<ref name="dev_beh_peds_2009" /> Most of these cases (75–90%) are believed to be due to issues that occur around the time of birth, often just after birth.<ref name="Yar2013" /> Multiple-birth infants are also more likely than single-birth infants to have CP.<ref name="saunders_2011" /> They are also more likely to be born with a [[low birth weight]].<ref>{{cite journal |vauthors=Demeši Drljan Č, Mikov A, Filipović K, Tomašević-Todorović S, Knežević A, Krasnik R |title=Cerebral palsy in preterm infants |journal=Vojnosanitetski Pregled |volume=73 |issue=4 |pages=343–348 |date=April 2016 |pmid=29308865 |doi=10.2298/VSP140321019D |doi-access=free}}</ref>

In those who are born with a weight between 1&nbsp;kg (2.2 lbs) and 1.5&nbsp;kg (3.3 lbs) CP occurs in 6%.<ref name="Osk2013" /> Among those born before 28&nbsp;weeks of [[gestation]] it occurs in 8%.<ref name="Osk2016">{{cite journal |vauthors= |title=Erratum |journal=Developmental Medicine and Child Neurology |volume=58 |issue=3 |pages=316 |date=March 2016 |pmid=26890023 |doi=10.1111/dmcn.12662 |s2cid=221682193 |doi-access=free}}</ref>{{efn|Incorrectly stated as 11% in 2013 <ref name="Osk2013" />}} Genetic factors are believed to play an important role in prematurity and cerebral palsy generally.<ref name="hallman_2012" /> In those who are born between 34 and 37&nbsp;weeks the risk is 0.4% (three times normal).<ref name="poets_2012" />