SB 9.14.40

antarvatnīm upālakṣya
 devīṁ sa prayayau purīm
punas tatra gato ’bdānte
 urvaśīṁ vīra-mātaram
Synonyms: 
antarvatnīm — pregnant; upālakṣya — by observing; devīm — Urvaśī; saḥ — he, King Purūravā; prayayau — returned; purīm — to his palace; punaḥ — again; tatra — at that very spot; gataḥ — went; abda-ante — at the end of the year; urvaśīm — Urvaśī; vīra-mātaram — the mother of one kṣatriya son.
Translation: 
Understanding that Urvaśī was pregnant, Purūravā returned to his palace. At the end of the year, there at Kurukṣetra, he again obtained the association of Urvaśī, who was then the mother of a heroic son.