My husband and I agreed not to have children, yet I became pregnant. Can he force me to choose between divorce and having an abortion?

The agreement in question is divided into two parts: the first is the couple's agreement not to have children and the second is their decision to terminate the pregnancy if the wife becomes pregnant. The first part of the agreement is permissible since the ruling for 'azl [coitus interruptus] revolves around being lawful or disliked; there is a scholarly controversy on the matter (the various means of birth control take the same ruling as 'azl). According to either ruling, there is no sin in using it and therefore, it is permissible to agree on it. Jabir said: "We practiced 'azl during the Prophet's lifetime; he knew about it and did not forbid us [from practicing it]" [Muslim].

If it is permissible to enter into an agreement, then breaking it is considered a violation. Consequently, if the wife deliberately becomes pregnant, she breaks a permissible promise and this is a sin. Otherwise, she is not blameworthy.

The second part of the agreement is impermissible because it is unlawful to terminate a pregnancy except if:
1. A trustworthy Muslim physician determines that the pregnancy threatens the woman’s health.
2. The abortion takes place before 120 days of pregnancy.
3. The abortion does not result in harm that is equivalent to or greater than that caused by the pregnancy.

In the absence of the above, abortion is unlawful and both spouses err by entering into a sinful agreement. It is impermissible for the inquirer to obey her husband and terminate the pregnancy since there is no obedience to any anyone if it involves disobeying God. Ali narrated that the Prophet (peace and blessings be upon him) said: "Obedience is required in good deeds." The wife does not sin by breaching this part of the agreement; rather, she is blameworthy if she does as is her husband for commanding her to do so.

The ruling
The wife commits a sin by breaking her promise if she deliberately becomes pregnant. Abu Huraira narrated a raised chain hadith in which the Messenger of God (peace and blessings be upon him) said: "The traits of a hypocrite are three: When he speaks, he lies; when he promises, he reneges; when he is entrusted, he betrays his trust" [Bukhari and Muslim].

The wife incurs no sin if her pregnancy is not deliberate. In the above scenario, the spouses agreed on something unlawful which is to terminate a pregnancy when it occurs. It is impermissible for the husband to order his wife to do so as it is likewise impermissible for her to obey him [even] if he insists. The couple should know that a pregnancy is a blessing from God the Almighty Who He is the [child's] protector and guardian because He is the Lord of the worlds. God the Almighty says: “If ye take a dislike to them it may be that ye dislike a thing, and Allah brings about through it a great deal of good” [4:19].

Each person must know his place and not fight the will of God the Almighty because He is never overpowered. Our destiny is predetermined so we must accept it; this is better for us both in this world and in the hereafter.
God the Almighty knows best.