This point is clearly stressed in the Holy Qur’an in the following verse...
The carrying of the (child) to his weaning is (a period of) thirty months. At length, when he reaches the age of full strength and attains forty years, he says, "O my Lord! Grant me that I may be grateful for Thy favor, which Thou has bestowed upon me, and upon both my parents, and that I may work righteousness such as Thou mayest approve; and be gracious to me in my issue.
She has to put up with many hardships from the time that she gets pregnant. She has to give a lot of her own energy to the fetus that is growing inside her. That is why she gets weak and develops many problems during pregnancy. The Period of Pregnancy As the fetus grows it draws more and more of the materials from the mother’s body. It even affects her bones and her nerves. At times, it even does not let her rest, eat or sleep.
Near the end of the period of pregnancy when the baby has grown, it even becomes difficult for the mother to sit up or stand up. However, the mother suffers all these difficulties due to the love she has for the baby that will soon be born: the baby that will smile at his mother once it is born. Delivery is one of the hardest to bear periods of a mother’s life. There are even mothers who lose their precious life during delivery.