The Gemara in Sotah (דף י"א:) tells us that בזכות נשים צדקניות שהיו באותו הדור נגאלו ישראל ממצרים, in the merit of the righteous women of that generation, the Jews were redeemed from Egypt. Jewish women played a major role in bringing about the Exodus. The men, apparently, were sad and depressed, believing that there was no hope. For example, when Amram's wife gave birth to a girl, he called her Miriam, which has the root מר, meaning bitter, because the Egyptians embittered the lives of the Jews. The Midrash says that Amram, who was a leader of his people, actually divorced his wife rather than have more children who would be slaves. Jewish women, however, in the tradition of Sarah, Rivkah, Rachel, and Leah, wanted only to build the Jewish nation, and were determined to overcome all obstacles.
According to the Midrash, when the women went out to draw water, a miracle took place and they found fish in the water. With water and fish, they refreshed their tired husbands who were exhausted after the days' work. They would also console their husbands, saying that everyone will be saved soon. Despite Paroh's decrees about killing children, they continued to have babies, showing the utmost faith. They were rewarded for this faith by Hashem because when the women were forced to abandon their newborns, He sent an angel to help feed them, and, miraculously, according to the Midrash, preserve the babies under the earth. When the Egyptians came to search for the babies, therefore, they found none because they were hidden under the ground. Only when they grew up did these children return to their parents; the Egyptians were shocked as to how Jews had managed to survive.
We see from these ideas of the Midrash that Hashem rewarded the bravery of the Jewish women by performing various miracles that helped keep the Jewish nation alive. If not for the extraordinary efforts of these women, it is possible that many more Jewish lives would have been lost and the nation may never have developed properly. Hashem obviously responds to people who sacrifice a lot to have faith in Him; Chazal thus tell us that it was really these women who brought about the redemption from Egypt.