Zero of nine may be 30%, and a 10% risk isn't zero.
Dammann
O
O
D002547:Cerebral Palsy / Q000209:etiology*; D004200:Diseases in Twins / Q000209:etiology*; D005260:Female; D005313:Fetal Death / Q000150:complications*; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D014427:Twins