More than a quarter of the women, however, reported that the Zika epidemic — which has swept across the country since mid-2015 — had not discouraged them from trying to have a child.
Sixteen percent said they had not been planning to get pregnant in any case.“The results provide an important first glimpse into how Zika has shaped pregnancy intentions among women in Brazil,” said co-author Marcelo Medeiros, a professor at the University of Brasilia.
While Zika causes only mild symptoms in most people, pregnant women with the virus risk giving birth to babies with microcephaly — a crippling deformation that leads to abnormally small brains and heads.
More than 1.5 million people have been infected with Zika, mainly in Brazil, and more than 1,600 babies have been born with microcephaly since last year, according to the World Health Organization (WHO).
The UN’s global health agency ended the Zika global health emergency — declared in February 2016 — last month.
Brazil has refused to downgrade the risk, and some experts have criticised the WHO decision.
In the survey, women of colour were more likely to report avoiding pregnancy than white women.
There was no significant difference, however, among religious groups, with 58 percent of Catholics and 55 percent of evangelical women saying they had sought to avoid pregnancy.
“Brazil must urgently re-evaluate its reproductive health policies to ensure better access to contraception,” the authors wrote in BMJ.
The survey data was extracted from a larger study called the Brazilian National Abortion Survey, Medeiros told AFP.