LoB verse 35
35. When the small pools of water become too hot because of the scorching heat of the autumn sun, the poor, small creatures, with their many family members, suffer terribly, as poor householders with too many family members suffer economic strains and yet go on begetting children because of uncontrolled senses.
Human life is meant for controlling the senses, for uncontrolled senses are the cause of material bondage. But for fools sense enjoyment is the pivot of life's activities. All men undergo hard, laborious duties all day and night and in all seasons of the year, only for the sake of sense pleasure with their mates. These foolish creatures have no information of other enjoyment. In a godless civilization especially, sense pleasure, accepted in the name of culture and philosophy, is all in all. Men who are addicted to this pleasure are called kṛpaṇas.
When the kṛpaṇas have too many children, they suffer the scorching heat of family life, and then similar leaders advise them to undertake family planning. The idea of this family planning is that sense pleasure should not be curtailed, but birth control should be accomplished by artificial measures. Such methods of birth control are called bhrūṇa-hatyā, or killing the child in embryo. Such killing is a sinful act, and in the revealed scriptures a specific hell is designated for those who commit such sins.
Spiritual culture means pursuing a better engagement in life. When a man engages in such cultural life, the desire for mating automatically abates, and the sufferings of uncontrolled family life are mitigated without artificial means.
The attention of a human being, therefore, should be drawn to the cultivation of the human spirit, for this will gradually protect him from all sorts of discomfiture and elevate him to a higher status of life for real and eternal enjoyment in personal contact with the Personality of Godhead, Śrī Kṛṣṇa.