Abortion is permitted even in Orthodox Judaism PROVIDED the mother’s life is in imminent danger (in this case, it is REQUIRED, not merely permitted) or for cases in which there are two fetuses and one is given virtually no chance of life, AND if the fetus is not aborted the other healthier fetus will also die. To save the life of the healthy fetus, the other fetus may be aborted. However, I don’t believe abortion is required according to Halakhic Law in this instance. There are also so-called leniencies in abortion from the Orthodox Jewish perspective, including rape, incest, and SEVERE genetic abnormality such that if the baby were born, it would most likely not survive for long and be in pain. Orthodox rabbis differ regarding the allowance of abortion in such cases, dependent on the psychological damage the mother might incur carrying her baby to term. Abortion is NOT required in these instances.
IVF is permitted in Orthodox Judaism since it is a means of fulfilling the commandment to be fruitful and multiply, which trumps the artificial means used to have children. However, there are disputes among Orthodox rabbis regarding whether or not the sperm and egg MUST be those of the natural parents, or whether a donor is permitted. Halakhic Law in these issues is quite complex and impossible for me to sum up in a single post. I recommend for anyone who is interested in pursuing more information on this topic to access the JewishVirtualLibrary website.