By Mathew Charles
David hopes others will follow his example
At the age of 47, David Mendez Castro, an evangelical pastor with three grown-up children, unexpectedly found himself father of a fourth.
Just over a year after his son's birth, he took a decision which for many in his position would be unthinkable.
He had a vasectomy.
"I had a vasectomy for various reasons. Children cost money and we didn't want that extra burden. Also, my wife is young, so it was convenient for me," he explained.
Spreading the Gospel
David's decision was a personal one, but he has decided to use his experiences to educate others in his community - and it hasn't been easy for him.
"A lot of people have been critical of me.
"Some think I am damaging the Church's reputation, but whatever people think, it's been worth it because I've seen lots of changes and families are thanking me".
David's decision was particularly surprising in light of his religious position.
In indigenous communities where myths about basic anatomy and human reproduction abound, family planning is often considered an insult to traditional values or even a sin.
"Family planning is not a sin," David argued.
"The Bible says women are more delicate than men and men should treat them accordingly, but they don't.
"Men should be ashamed of themselves putting their wives under the knife when they could have a vasectomy instead."
A widespread problem
In Guatemala only 40% of all women use any form of birth control, including natural methods.
Half have a child before the age of 19 and 20% have two or more children by their 18th birthday.
By the time women reach their early 30's it is not uncommon for them to have already given birth to seven or eight children ,with at least one of these children not having survived past infancy.
Dr Santizo is encouraging more men to have vasectomies
The Guatemalan government last year made the promotion of family planning and reproductive health a priority, and it is slowly catching on.
The use of condoms is steadily increasing, for example, but they are not widely available. And challenging 'macho' attitudes is proving difficult.
"It's a socio-cultural problem. Vasectomies just haven't taken off here. But we have created special programmes to try and encourage more men to consider the option," Dr Roberto Santizo from the Guatemalan Health Department told the BBC.
Challenging the norm
Guatemala has one of the highest birth rates in Central America.
70% of families live below the poverty line here and high numbers of children are undoubtedly contributing to the problem.
By targeting men, who traditionally make family planning decisions, it's hoped more couples will consider the various options open to them.
A lack of resources, widespread ignorance and social taboos mean this is not going to be an easy battle for Guatemala.
But Pastor David Mendez Castro is optimistic.
"When people realise this is about the future, about the future health of themselves and their family, the idea will catch on."