The Muslim should not believe that any harm may be caused by reciting some soorahs of the Qur'an; this notion is contrary to the words of Allah, may He be glorified and exalted (interpretation of the meaning): Say: It is for those who believe, a guide and a healing [Fussilat 41:44].
There is nothing in the books of the fuqaha' or scholars, or in the reports from the righteous early generations that anyone used to warn pregnant women against reading Soorat az-Zalzalah; rather those who had memorised the Holy Qur'an, both men and women, have always been eager to complete the recitation of the Qur'an within the period in which they usually do that, without any exception. The one who dares to warn against reading a specific soorah -- even in a specific situation -- has dared to do something serious.
Yes, it cannot be denied that this soorah or others may be beneficial in making it easier for the pregnant woman to deliver the baby if that is proven by experience, but that does not imply the opposite, that it could lead to miscarriage at the beginning of the pregnancy, because there can be no evil or harm in the words of Allah, may He be glorified and exalted, under any circumstances.
Ibn al-Qayyim (may Allah have mercy on him) said:
Chapter on difficult birth: al-Khallaal said: Abdullah ibn Ahmad told me: I saw my father writing for women who had difficulty in giving birth, on a white cup or something clean; he would write the hadeeth of Ibn Abbaas (may Allah be pleased with him): There is no god but Allah, the Most Forbearing, the Most Generous; Glory be to Allah, the Lord of the Mighty Throne; praise be to Allah the Lord of the Worlds. On the Day when they will see that (torment) with which they are promised (i.e. threatened, it will be) as if they had not stayed more than an hour in a single day. (O mankind! This Quran is sufficient as) a clear Message (or proclamation to save yourself from destruction)' [al-Ahqaaf 46:35]; as if they had not tarried (in this world) except an afternoon or a morning' [Naaziaat 79:46].
Al-Khallaal said: Abu Bakr al-Marwazi told us that a man came to Abu Abdullah and said: O Abu Abdullah, will you write something for a woman who has been having difficulties in labour for two days?
He said: Tell him to bring a large cup and some saffron. And I saw him writing for more than one person and narrating from Ikrimah that Ibn Abbaas said: Eesa (blessings and peace of Allah be upon our Prophet and upon him) passed by a cow that was having difficulty giving birth and she said: O Word of Allah, pray to Allah to relieve me of the difficulty I am in.
He said: O Creator of a soul from another soul, the One who delivers one soul from another, deliver her. Then she delivered her calf and stood up and began to smell him. He said: So if a woman is having difficulty in childbirth, write this for her. And the ruqyah mentioned above, if you write it for her it will be beneficial. End quote.
Zaad al-Maaad, 4/326
Shaykh Ibn Uthaymeen (may Allah have mercy on him) was asked the following question:
Are there any verses that could be recited in order to make childbirth easier for the woman?
I do not know anything of that nature from the Sunnah, but if one recites over the woman whose labour has begun verses that speak of ease, such as Allaah intends for you ease, and He does not want to make things difficult for you[al-Baqarah 2:185]; or that speak of pregnancy and childbirth, such as: nor does a female conceive (within her womb), nor brings forth (young), except by His Knowledge [Fussilat 41:47]; or When the earth is shaken with its (final) earthquake, And when the earth throws out its burdens [az-Zalzalah 99:1-2], - that will be beneficial, by Allah's leave. All of the Qur'an is healing; if the reciter and the one over whom it is recited both believe in its effects, then it will inevitably have an effect, because Allah, may He be exalted, says (interpretation of the meaning):
And We send down from the Qur'an that which is a healing and a mercy to those who believe (in Islamic Monotheism and act on it), and it increases the Zalimoon (polytheists and wrong-doers) nothing but loss
This verse is general in meaning: healing and mercy includes healing of hearts from the diseases of doubts and whims and desires, as well as healing of bodies from chronic diseases.
End quote from Fataawa Noor ala ad-Darb, Fataawa al-Aqeedah/al-Ibaadah, tape no. 257, side A.
Shaykh Ibn Uthaymeen (may Allah have mercy on him) also said:
As for experience, if you go through an experience and you reach a conclusion that has a basis in Islamic texts, then this is a confirmation of what is in the texts. But if the conclusion refers to something that is not mentioned in the texts, then there are two scenarios: if this conclusion is based on empirical science, then undoubtedly it is valid and is to be taken into account; if, however, it has to do with shar i matters, then it is not to be taken into account (because there is no reference to it in the Islamic texts).
There is a basis for seeking healing by means of the Holy Qur'an, because Allah, may He be exalted, says (interpretation of the meaning):
And We send down from the Quran that which is a healing and a mercy to those who believe
There is a basis for this, so if some particular verses of the Qur'an are tried for some disease and prove to be beneficial, this experience is confirmation of what it says in the Qur'an about it being a healing for people.
With regard to matters other than worship, it is undoubtedly subject to experience and empirical science. If a person, for example, has knowledge and experience of what the earth produces of herbs and the like, and he goes out to the countryside and gathers what he thinks is beneficial and tries it, then whatever conclusions he reaches may be valid.
End quote from al-Liqa' ash-Shahri, no. 37, question no. 26
To sum up: none of the soorahs of the Qur'an can harm a pregnant or breastfeeding woman or anyone else; rather they are good and beneficial, and bring barakah (blessing) to the one who recites them and the one who listens to them, by Allah's leave.
And Allah knows best.
Reproduced from Islam QA