Charak Samhita
अकालयोनिगमनान्निग्रहादतिमैथुनात्। शुक्रवाहीनि दुष्यन्ति शस्त्रक्षाराग्निभिस्तथा ॥१९॥
Shukra dhatuvaha srotamsi are affected due to sexual acts at inappropriate hours and through non-vaginal tract, suppression of discharge of semen, excessive coitus and faulty surgical procedures, or if kshara and agni karma procedures are administered for cauterization.
english translation
akAlayonigamanAnnigrahAdatimaithunAt। zukravAhIni duSyanti zastrakSArAgnibhistathA ॥19॥
hk transliteration by Sanscript