Now I found this very enlightening, hope it helps some.
ABORTION
The Torah provides a monetary punishment (as opposed to capital punishment) for situations in which - through physical assault - a person causes a woman to miscarry. Whether the assault was intentional or not, such occurrences were a reality and the consequences had to be addressed. The Torah values ALL human life.
On the other hand, there is no explicit case in the Torah regarding a woman causing herself to miscarry (i.e., abortion).
I have heard some authorities explain this silence by pointing out that the deliberate abortion of one's child was beyond the pale of ancient Hebrew morality. In other words, ancient Hebrew women would be horrified at the suggestion to abort their child. There was no need to address the phenomenon of abortion, because it didn't exist.
If a phenomen didn't exist, then the Torah wouldn't explicitly mention it. Other modern questions include such things as 'is it permissable to use electricity on Shabbat;' 'can you drive in a car,' can you use automatic light timers,' and so on. These issues didn't exist and so were never explicitly mentioned in the Torah.
Nonetheless, the WRITTEN TORAH commands us to use the ORAL TORAH (a legal methodology) to derive legal decisions on any new phenomenon that was not explicitly covered in the Torah. That's what keeps Torah alive and relevant for every generation.
So, there have been legal decisions regarding abortion. For example, if a pregnancy presents a true threat to the physical life of the mother, then the unborn child is legally classified as one who is pursuing the mother to kill her. Laws on self-defense kick in, and the mother is legally obligated to save her life, even though that means killing the unborn child.
HAVING CHILDREN
Regarding the issue of having kids, only the man is commanded to be fruitful and multiply in the Torah. The woman has no obligation. In fact, the woman is also the power-broker when it comes to having sex. She always has the RIGHT to say yes or not to her husband's sexual advances.
Nonetheless, her conscience should compel her to assist her husband so that he fulfills his Torah obligation. If she is physically and emotionally capable of having children, then she should do so. If she refuses, then her husband has grounds for divorcing her because he is under the Torah obligation to procreate.
On the other hand, if the husband was married previously and had children by that previous marriage, then he could be considered as already having fulfilled his obligation to procreate, and therefore his second wife can just flatly refuse to have any children at all.
In the final analysis, a woman has complete control over the decision to deliberately procreate.
BIRTH CONTROL
Certain types of birth control (preventing conception) are permissable by Jewish law.