SB 6.14.11

tasya bhāryā-sahasrāṇāṁ
sahasrāṇi daśābhavan
sāntānikaś cāpi nṛpo
na lebhe tāsu santatim

tasya—of him (King Citraketu); bhāryā—of wives; sahasrāṇām—of thousands; sahasrāṇi—thousands; daśa—ten; abhavan—there were; sāntānikaḥ—quite capable of begetting sons; ca—and; api—although; nṛpaḥ—the King; na—not; lebhe—obtained; tāsu—in them; santatim—a son.

This Citraketu had ten million wives, but although he was capable of producing children, he did not receive a child from any of them. By chance, all the wives were barren.