![](img011.GIF) |
Birth weight was standardised for sex and
gestational age, giving a birth weight standard deviation score (SDS). The standardisation
was based on reference values from Swedish singletons born in 1977-1981 with a gestational
age of at least 28 weeks. Hence in this study we focused on mortality from 28 weeks
onward. From 28 to 32 weeks of gestation there was hardly any difference in birth weight
SDS between twins and singletons. The growth disadvantage of twins became obviously after
32 weeks. The same pattern of difference in birth length SDS was also seen. |