Okay, I am basing this theory on all that I can think of that I have heard in the DBZ universe.

1)One of the reasons why being "low class" is such a diss is because they arn't considered individuals by the "nobels". This is easy to assume considering Turles's comment on how lower level solders all look the same (and no he isnt related to Goku). Also, they are seemingly expendable since it is from that class of saiyin that children are deployed. Which brings me to my second point.

2)Seeing how a certain portion of the population is off planet most of the time, I imagine that coming back home is akin to Sailors getting a break on land. This is evident in how, when Bardock's son is mentioned, the female who bore him is not. I mean, they didn't just not give her a name, they didn't even acknowledge her existence. If Bardock was attached to anyone of significants to him, they would have mentioned it (since they took the time to mention the child that came from it).It seems like it would not be uncommon for soldiers on missions to have many children when they comeback, making it inconsequential as to who the mother is. Furthermore, because of Fasha's existence on the away team, and the apparent abandonment of the children by their low class mothers, it seems that their situation is not much different. You get knocked up? Well, hurry up and have your baby and get back to work. (Its because of this theory that I think the whole "women cant be supersaiyin" is a sexist load of bunk).

3) This refers to the above arguement. A question might be posed as to why Radditz was not immediately blasted away to another planet when he was born? First of all, how do you know that he wasn't? Just because they got sent to planets to destroy them, doesnt mean that they wernt retrieved later on. Also, when did Raditz get to interact with Goku? He said that he did in the anime because he recognized him and well...said he did. Well, first of all, since they have the same mother (because he doesnt refer to him as a half brother)I am thinking that Radditz may have been in the "custody" of his planet based parent (mommy). Since she gave birth rather recently when Bardock went to look at Goku, I can only assume that he had come with her and had seen his brother born before going to another planet on a mission. And thereby surviving. Side note, Fasha, CAN NOT be their mother because that just doesnt make sense. No where was she pregnant and she was in a completely different place when Goku was born. Also, when she talks about goku she says, "didnt you have a kid? Are you going to visit him?" It it was her child, she wouldnt have any question as to wether Bardock had a kid. I mean, She can't FORGET that she popped out a baby.

3)Now, some of you may be asking, "what about Vegeta? His father obviously got to keep him (albeit a short time)". My answer for this is simply that he is of higher class. It was probably considered meaningless for lower class citizens to be parents since they had no mental worth, "simple low class Saiyan! (Vegeta)." Obviously, the better (cleaner) breeding you had, the more you were considered not just an individual, but an individual of worth and intellegence. Saiyans had a very spartan mentality when it came to weakness in the Genetic line, which is probably how they became so naturally strong.

4)Yes, I know I am extrapolating all of this new point from one source (Fasha). But I believe that women on Vegeta probably had an equal standing to the men. Fasha was not treated any different nor segregated. Also, because of Ki, ones size would not really matter, I mean look at Vegeta! He's tiny! Also, you may say, "if women were on equal standing, why does he treat them so demunitivly?" That can be answered quite simply, HE WAS TAKEN AS A CHILD!!! It is my opinion that the reason he has such a hangup on his cultural back ground is one, its a dead race so who else is going to keep traditions alive, and two, he was raised on Frieza's ship so he has HARDLY any personal experience of his own race's culture. Due to him being the prince, he feels he must compensate by always putting it out there in the open. The truth is, Vegeta was raised on a cruiser full of alien dudes who probably raped and pillaged all the time. So its not hard to believe that he would refer to Bulma and such as "woman".

If I remember more stuff I will update this. If you have any comments or questions about my theory I will be glad to hear them!