d'où

Meaning

Draws the consequence in a short formula, followed by a NOUN rather than a clause.

Position and punctuation

at the start of the sentence · a comma before

Example

Les deux enquêtes ne portent pas sur la même période, d'où des écarts importants.

The two surveys do not cover the same period, hence the significant differences.

In the DELF

the C1 synthesis

The trap

D'où is followed by a NOUN, never a finite clause: "d'où des écarts", not "d'où il y a des écarts".