Research suggests as many as one man in ten who's had a vasectomy is now seeking a reverse operation, having met a new partner.
University of Auckland PhD candidate Gareth Terry, who's studying New Zealand's high vasectomy rate, says anecdotal evidence shows a growing trend for reversals.
He says the overwhelming reason given is re-marriage, although the death of a child is also a motivating factor.
Mr Terry says vasectomy is more popular in New Zealand than most other countries, with nearly one in four married men having the operation.
One Christchurch reproductive specialist, Greg Phillipson says he is seeing about three men a week for the reversal.
He says men seeking to undo their vasectomies are mainly aged in their 30s and 40s.
Mr Phillipson says if the reversal is done within a few years of the vasectomy, the success rate is 90%, but that reduces to 50% after 10 years.