As a Messianic-Jew, it is a prohibition to three biblical commandments I am conscience of, making me disinclined to support it. Peacefully, I say these just for clarity's sake:
Genesis 1:28
"[...] Be fruitful and multiply."
In our viewpoint, even neutering an animal by our own volition would break that when we must keep life existent throughout the ages. For a woman, once she receives the surgery, she may not longer bare children, which might be the end of her family's lineage, alas. God charged mankind and the animals to obey that for those reasons.
"Thou shalt not kill".
Exodus 20:13
To us, the sperm is considered as a living creature, though it may be unformed as a babe yet. If it is not jeopardizing the mother's survival in some cases, which it may be necessary, it is as taking away the life thereof unjustly.
Exodus 13:2
"Sanctify unto me all the firstborn, whatsoever openeth the womb among the children of Israel, both of man and of beast: it is mine."
It may be likened that the unformed soul could not fulfill its purpose having its life cut abruptly unable to keep that commandment to the Lord.
I believe that Jesus himself wills that rather we should just cherish them. There some cases of illegitimate children born, yes, but we must care for them still, not despise them, for casts away their chances at "correcting" what their parents may have done wrong. It does grieve me to hear such stories on how challenging it can be I imagine, but there are better options than just taking away their rights as if they were of no value.