Birth Weight Ratio as an Alternative to Birth Weight Percentile to Express Infant Weight in Research and Clinical Practice: A Nationwide Cohort Study

Table 2

Population-attributive risk of abnormal fetal growth, for four definitions of abnormal growth by birth weight ratio and birth weight percentile.

	Population-attributive risk percentage (PAR%)
	Birth weight ratio		Birth weight percentile
	<0.80	<0.85	<p5	<p10
25–28 weeks
Perinatal death	26	28	18	23
Composite adverse outcome	3	3	2	2
29–32 weeks
Perinatal death	24	27	14	20
Composite adverse outcome	5	6	3	4
33–36 weeks
Perinatal death	29	35	19	25
Composite adverse outcome	11	12	10	13
37–42 weeks
Perinatal death	18	24	17	22
Composite adverse outcome	9	11	7	8