Variable

P-value

OR (95% confidence interval)

OR adjusted^† (95% confidence interval)

Monochorionic placentation

0.004

2.043 (1.264 - 3.300)

1.666 (1.010 - 2.745)*

Birth weight (grams)

<0.001

0.998 (0.997 - 0.999)

0.998 (0.998 - 0.999)**

Nulliparity

0.032

1.711 (1.047 - 2.796)

1.009 (0.602 - 1.690)

Gestational age (weeks)

0.638

0.994 (0.970 - 1.019)

Sex distribution, male

0.555

0.870 (0.549 - 1.380)

Age mother (years)

0.256

0.976 (0.936 - 1.018)