SB 4.27.6

tasyām ajanayat putrān
 purañjanyāṁ purañjanaḥ
śatāny ekādaśa virāḍ
 āyuṣo ’rdham athātyagāt
Synonyms: 
tasyām — within her; ajanayat — he begot; putrān — sons; purañjanyām — in Purañjanī; purañjanaḥ — King Purañjana; śatāni — hundreds; ekādaśa — eleven; virāṭ — O King; āyuṣaḥ — of life; ardham — half; atha — in this way; atyagāt — he passed.
Translation: 
The great sage Nārada then addressed King Prācīnabarhiṣat: O one whose life span is great [virāṭ], in this way King Purañjana begot 1,100 sons within the womb of his wife, Purañjanī. However, in this business he passed away half of his life span.
Purport: 

In this verse there are several significant words, the first of which are ekādaśa śatāni. Purañjana had begotten 1,100 sons within the womb of his wife and thus passed away half of his life. Actually every man follows a similar process. If one lives for one hundred years at the utmost, in his family life he simply begets children up to the age of fifty. Unfortunately at the present moment people do not live even a hundred years; nonetheless they beget children up to the age of sixty. Another point is that formerly people used to beget one hundred to two hundred sons and daughters. As will be evident from the next verse, King Purañjana not only begot 1,100 sons but also 110 daughters. At the present moment no one can produce such huge quantities of children. Instead, mankind is very busy checking the increase of population by contraceptive methods.

We do not find in Vedic literatures that they ever used contraceptive methods, although they were begetting hundreds of children. Checking population by contraceptive method is another sinful activity, but in this Age of Kali people have become so sinful that they do not care for the resultant reactions of their sinful lives. King Purañjana lay down with his wife, Purañjanī, and begot a large number of children, and there is no mention in these verses that he used contraceptive methods. According to the Vedic scriptures the contraceptive method should be restraint in sex life. It is not that one should indulge in unrestricted sex life and avoid children by using some method to check pregnancy. If a man is in good consciousness, he consults with his religious wife, and as a result of this consultation, with intelligence, one advances in his ability to estimate the value of life. In other words, if one is fortunate enough to have a good, conscientious wife, he can decide by mutual consultation that human life is meant for advancing in Kṛṣṇa consciousness and not for begetting a large number of children. Children are called pariṇāma, or by-products, and when one consults his good intelligence he can see that his by-products should be the expansion of his Kṛṣṇa consciousness.