How does the author use foreshadowing in Measure for Measure?

In Act One, Scene Two the concept of dowries and contracts is addressed. When Claudio shares the reasons for his arrest with Lucio, he talks about the “true contract” that exists between Claudio and Juliet, as well as the fact that their engagement gave Claudio the right to the “possession of Juliet’s bed”. All that's missing is the actual wedding itself, which has been delayed pending the “propagation of a dower”. Sadly, Juliet becomes pregnant before the dowry is established. The concept of dowries is thus foreshadowed, and the parallel between Claudio and Angelo is constructed, to be exposed later.