कर्मात्मकत्वाद्विषमांशभेदाच्छुक्रासृजोर्वृद्धिमुपैति कुक्षौ| एकोऽधिको न्यूनतरो द्वितीय एवं यमेऽप्यभ्यधिको विशेषः ||१६||
Due to past deeds and uneven division of the union of sperm and ovum, one among the twins is having better development in the womb while the other one is poorly developed. Thus, there is difference in the twins also.
कस्माद्द्विरेताः पवनेन्द्रियो वा संस्कारवाही नरनारिषण्डौ| वक्री तथेर्ष्याभिरतिः कथं वा सञ्जायते वातिकषण्डको वा ||१७||
Why does the progeny becomes dwireta (hermaphrodite), pavanendriya (devoid of semen), samskaravahi (one whose semen pathway is obstructed by vata), narashanda (sterile male ), narīshanda ( sterile female), vakrī (curved), irshyabhirati (one with mixoscopia) and vatikashandaka (one whose testicles are destroyed due to vayu and agni (pitta))
In case the zygote is formed by equal dominance of sperm and ovum or by impaired gamates, the progeny has characters of both female and male, resulting in dwireta (hermaphrodite). Vayu by afflicting the shukrashaya (site of semen) of the fetus causes pavanendriya (devoid of semen).
शुक्राशयद्वारविघट्टनेन संस्कारवाहं कुरुतेऽनिलश्च| मन्दाल्पबीजावबलावहर्षौ क्लीबौ च हेतुर्विकृतिद्वयस्य ||१९||
When vayu obstructs the passage of the site of semen, it causes samskaravahī. When the parents have sluggish and diminished reproductive factors, are weak, or are not excited or happy during coitus, they cause the two disorders—narashanda and narīshanda (male and female sterility).
Due to the mother’s lack of desire (for coitus) or complicated posture (during coitus) and also due to poor quality of shukra of the father, (the progeny) is born with vakrī (with curved organ). Irshyabhirati(one with mixoscopia) is caused if the parents are subdued by jealousy and are having only mild passion towards each other.