NO MORE DEATH BY CHILDBIRTH IN DB UNIVERSE!
That's just pure madness that this cliché is so popular among ff writers, that they throw it as easy as most of the dictators give death sentence. I know that it used to be popular method to kick mother away, but the facts are that lowering the death by childbirth rate was the matter of washing hands before midwife or doctor start to act (especially if he had touched corpses before). Holy Grail, they have modern looking hospitals! They have healing tanks, but you think that they can't stop haemorrhage or preform modern CS? For warrior race saving woman fighting herself and giving birth to nest generation would be the first one to be given the place in it.
And no, death by childbirth doesn't mean that woman kissed child, whispered last words and passed away in silence. It was always awfully bloody and smelly beyond imagination of most people accompanied by horrible pain and long agony.
Pregnancy isn't a disease, giving birth is a normal process that female are suitable for, so find another way to get rid of unwanted mums.
Sorry, but that cliché is my private berserk button no matter where.
Back to the topic I doubt if Sayians behaved in one pattern. We all have cultural codes, but even so our behaviour vary between different norms. I'd see them relying on matchmakers who would work comparing family trees, social status and psychical factors and arrange short lasting marriages. In my unborn ff the children belonged to family of the stronger mate, who had a dominate position. After some years such unions would be automatically finished, but there would be stories about those who stayed longer with each other or even renegotiated contracts (that happened to Bardock, but no-one knew the reasons)
Oh, and King was married to his throne, young Vegata's mother was chosen by his advisor, but her identity were kept in secret, even from the child. I find that more suitable and interesting than typical imagination of marriage.
