Paternity after vasectomy with two previous semen analyses without spermatozoa.
BACKGROUND
The risk of paternity after vasectomy is rare but still exists. Overall failure to achieve sterility after vasectomy occurs in 0.2 to 5.3% of patients due to technical failure or recanalization. The objective of this report was to describe a rare but notable case of proven paternity in which the semen analyses had not given evidence of spermatozoa.


METHODS
A 44-year-old vasectomized man whose semen analyses had shown azoospermia became a father four years after sterilization. Blood sample DNA analysis on the child and husband proved biological paternity. Vasectomy may fail in the long run even without spermatozoa in semen analysis. The patient must be aware of this possibility.
Lucon
Marcos
M
Department of Urology, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil. mlucon@uol.com.br
Lucon
Antonio Marmo
AM
Pasqualoto
Fabio Firmbach
FF
Srougi
Miguel
M
D053713:Azoospermia / Q000175:diagnosis; D016172:DNA Fingerprinting; D005260:Female; D005306:Fertilization; D006801:Humans; D008297:Male; D010334:Paternity; D011247:Pregnancy; D013076:Sperm Count; D013094:Spermatozoa / Q000737:chemistry*; D017211:Treatment Failure; D014659:Vasectomy