Positive Commandment 212 (Digest)
"Be fruitful and multiply"—Genesis 1:28.
We are commanded to reproduce in order to perpetuate the human species. For this reason, a groom on the night of his wedding is exempt from the biblical obligation to recite the Shema, for his mind is presumably preoccupied with the impending mitzvah that he will perform.
This mitzvah is only mandatory for males.
Translation of (the unabridged text of) Sefer Hamitzvot by Rabbi Berel Bell, member of the Rabbinical Court of Montreal and director of Teacher Training for the Jewish Learning Institute.
From "Sefer Hamitzvot in English," published by Sichos in English