Towards the beginning of Parashat Toledot, we read of Rivka's difficulties during her pregnancy, in response to which "she went to seek out the Lord" (25:22). Where exactly did she go, and what was she "seeking"?
Rashi explains that Rivka went to the prophet Shem to find out "what will be with her in the end." Rivka feared that her unusual pains would mean an unsuccessful pregnancy, and so she anxiously sought a prophetic prediction as to the outcome of her pregnancy. As we read in the next verse, she was informed that the difficulties she experienced resulted from the two opposing nations gestating in her womb, and she will deliver two healthy children who will establish two powerful peoples. Other commentaries, including Targum Onkelos and Chizkuni, explain similarly. (This also appears to be the interpretation of the Rashbam; see also Derashot Ha-Ran, 2.)
The Ramban, however, disagrees, claiming that the verb employed in this verse – d.r.sh.- always refers to prayer when used in reference to "seeking" God. Thus, according to the Ramban, the Torah here tells that she went to pray to the Almighty for relief. (This is the view as well of Pirkei De-Rabbi Eliezer, 32.) God's response, namely, the information that she will bear twins from whom two great nations will descend, was intended to offer encouragement and hope, which would help her deal emotionally with the pain she endured.
Rav Yaakov Koppel Schwartz, in his work Yekev Efrayim, suggests a novel interpretation of this verse, claiming that Rivka perhaps did not actually experience any unusual pains during her pregnancy. Rather, when the verse states, "The sons struggled inside her," it refers to a dream she beheld of two fetuses wrestling with one another inside her uterus. She therefore went to a prophet to learn the meaning behind this peculiar vision, and she was informed that the skirmishes between the two fetuses symbolize the struggle that will ensue between her two children, Yaakov and Esav, and their descendants. Thus, "she went to seek out the Lord" refers neither to prayer nor information concerning the outcome of her pregnancy, but rather to prophetic consultation for the purpose of deciphering her dream.