Charak Samhita
अन्यधातूपसंसृष्टमवसादि तथाऽष्टमम् । फेनिलं तनु रूक्षं च कृच्छ्रेणाल्पं च मारुतात् ॥१४०॥
Frothy, slender, arid, scanty, discomforting ejaculation is due to vata (dominance). Thus affected semen is incapable of fertilization (garbha).
english translation
anyadhAtUpasaMsRSTamavasAdi tathA'STamam । phenilaM tanu rUkSaM ca kRcchreNAlpaM ca mArutAt ॥140॥
hk transliteration by Sanscript