Where do other religions (apart from Christianity) stand on abortion?

“Take not life which Allah has made sacred” (6:151). As you said very correctly, the question is, When does life begin? However, the Quran kind of rules this out. Says Allah in the Qur’an: “So set you your face steadily and truly to the Faith: (Establish) Allah’s handiwork according to the pattern on which He has made humankind: no change (let there be) in the work (wrought) by Allah: that is the standard Religion: but most among mankind understand not.” (Al-Qur’an 30:30)-Translation taken by Abdullah Yusuf Ali. This verse actually rules out the concept of both, contraception and Abortion in Islam, since if we look at the pattern by which God has made humankind, it is as follows, according to the Quran: -

We created man from an essence of clay: then placed him, a living germ,

            In a secure enclosure.  The germ We made a leech; and the leech a lump of

            Flesh; and this We fashioned into bones, then clothed the bones with flesh;

            Then We develop it into another creation. (Surah Al-Mu'minoon, 23: 12-14)

Hence, if we carry out contraception or abortion, some stage "of God's pattern" will be disrupted and so, the action would contradict the Islamic verses. However, coitus interruptus is perfectly allowed in Islam according to the followind Hadeeth:

Jabir (RA)  said: “We used to practice (‘Azl) coitus interruptus during the days when the Qur’an was being revealed”. (Sahih Bukhari vol. 7, Hadith no. 136)

Hope that clarifies it all. :)