VIETNAM is seeing a boom in male births as increasing numbers of parents opt for sex-specific abortions.

Christophe Guilmoto of Descartes University in Paris, France, and his colleagues analysed population data collected by the General Statistics Office of Vietnam since 2000, plus two surveys which assessed birth rates in 2006 and 2007.

In 2001, the sex ratio in Vietnam was close to the biological norm of 105 male births per 100 female births, but this reached 111 to 100 by 2007 (PLoS One, DOI: 10.1371/journal.pone0004624).

Guilmoto also analysed statistics of access to prenatal ultrasounds, and found that there …