lying-in women

birth control

abortion

contraceptives

contraception

bring up sons to support parents in their old age

carry on the family line

Man is superior to woman

the more sons, the more blessings

 change attitude of viewing sons as better than daughters

 advocate healthy pregnancy and scientific nurture, and encourage late marriage and postponed child-bearing

family planning

baby boom period

marriage boom

legal age for marriage

aging of population

 natural growth rate

mortality rate

birth rate

overpopulation