Ibihugu bifite abagabo bafite ibitsina binini ku isi byamenyekanye, ariko ibihugu by’ibihangange nka Amerika n’Ubwongereza ntibiri ku mwanya wa hafi.
Ugereranije, abagabo bo muri Ecuador na Cameroon bafite ubugabo bunini, bafite igitsina gipima hafi santimetero 17 (17cm) kuva aho gitereye kugeza ku mutwe, iyo cyayafashe umurego.
Amerika n'Ubwongereza ntibigeze baza muri 50 ba mbere, aho Amerika yaje ku mwanya wa 60 hamwe n'abagabo bafite impuzandengo y’uburebure bw’ibitsina ingana na santimetero 15.5 (15.5cm). Ubwongereza bwaje ku mwanya wa 68, bufite aho uburebure bw’igitsina ku bagabo bungana na santimetero 13.1(13.1cm).
Abashakashatsi bari inyuma y'uru rutonde bavuze ko bahanganye n'ikibazo cyo kubona isano iri hagati y'uburebure bw'igitsina n'uburebure busanzwe, ariko bagasanga ibihugu bifite umubare munini w'umubyibuho ukabije bikunze kugira abagabo bafite igitsina gito, bikaba bishobora gusobanura uruhare rw’ibinure byinshi ku ngano y'igitsina.
Kugira ngo bamenye ibihugu bifite abagabo bafite ibitsina binini, abashakashatsi bo mu Budage bahujije ubushakashatsi burenga 40 buherutse gukorerwa ku bagabo ibihumbi.
Iri tsinda ryakuyemo amakuru ku bunini bw'ibitsina mu bihugu bigera kuri 90, hamwe n'ibipimo byagenzuwe ku bushake.
Mbere, abigisha imyitozo ngororamubiri bavuze ko abagabo bashobora kongera santimetero ku gitsina cyabo bagabanya ibiro gusa.
Mu bihugu 20 bya mbere, kimwe cya kabiri ni ibihugu bya Afurika, mu gihe bitatu byari muri Amerika y'Epfo, Amerika y'Amajyaruguru n'Uburayi.
Ibihugu by'Uburayi bifite abagabo bafite ibitsina binini muri rusange ni Netherlands yaje ku mwanya wa cyenda, France yaje ku mwanya 11 na Italy yaje ku mwanaya 19.
Mu bihugu byo muri Amerika ya Ruguru, abagabo ba Haiti bari ku mwanya wa gatanu, Cuba ku mwanya wa munani na Canada baje ku mwanya wa 13 ku isi.
Ibihugu bifite abagabo bafite ibitsina binini kurusha ibindi
Ubushakashatsi bwashyizwe ahagaragara n’ikinyamakuru cyo mu Bwongereza cyitwa Urology Journal mu 2015 cyifashishije abagabo 15,000 baturutse ku migabane itatu bwasanze impuzandengo y’uburebure bw’igitsina cy’umugabo, ari 5.16in.
Abashakashatsi kandi, bagaragaje ko uburebure bw'igitsina gabo bufitanye isano rito n'uburebure busanzwe.
Abagabo bafite umubyibuho ukabije bashobora bakunze kugira igitsina gito kubera ibinure byinshi hafi y’aho igitsina gitereye.
Ku bijyanye n’igitsina abagore bakunda, ubushakashatsi bumwe bugaragaza ko abagore bashimishwa no kuryama n’abagabo bafite ibitsina binini, ariko, na none bakishimira kubana n’abagabo bafite igitsina gito.
