变量名称

早产组(484例)

足月组(484例)

X²

P值

1.母亲年龄(岁)

<20

8 (1.65%)

2 (0.41%)

20~40

451 (93.18%)

467 (96.49%)

6.349

0.041

>40

25 (5.17%)

15 (3.10%)