Sentence:  This means that such factors as the health of the <WSD>parents</WSD> , particularly the mother , their ability to provide their children with the necessities of life , the degree of population density of a country and the shortage of housing facilities may legitimately be taken into consideration in determining the number of offspring . 
Meaning of the word marked with <WSD> tags:  a father or mother; one who begets or one who gives birth to or nurtures and raises a child; a relative who plays the role of guardian