Magungunan antisperm (ASA) - kwayoyin da ke jikin mutum ya ke haifar da kwayar cutar maniyyi.Krause 2017: 109) Samuwar ASA na ɗaya daga cikin dalilan raguwar haihuwa ko rashin haihuwa na asali: ASA yana shafar aikin maniyyi, canza yanayin tasirin acrosomal (AR), da kuma tarwatsa hadi, kafawa da haɓakar tayin (2013) haifar da rarrabuwa na DNA (Kirilenko 2017) Nazarin kan nau'ikan dabbobi daban-daban sun nuna alaƙa tsakanin ASA da taɓar ciki tayi kafin ko bayan fashewar (Krause 2017: 164) Ana bincika maganin hana haifuwa na ASA yayin haɓakar rigakafin rigakafin ƙwayar cuta ga mutane (Krause 2017: 251), tare da ragewa da sarrafa yawan namun daji (Krause 2017: 268).

Tun daga tsakiyar karni na 20, karkashin asarar “matsalar yawan mutane”, duniya ta kasance tana yaudarar farfagandar duniya da nufin rage yawan haihuwa da rage yawan jama'a. A yawancin ƙasashe masu tasowa, adadin haihuwa ya riga ya faɗi ƙasa da matakin sauƙi na yawan jama'a, kuma adadin tsofaffi daidai yake da yawan yara ko ma ya zarce shi. Aure yana ƙara ƙarewa cikin kisan aure kuma an maye gurbin shi da haɗuwa. Abubuwa na aure, liwadi da abubuwan wuce gona da iri sun sami matsayin fifiko. Depopulation, ba Tarihi "yawaitar mutane" ya zama sabon gaskiyar duniya.