IVF parents are choosing girls over boys in order to cut the child's risk of autism, as male babies are about 4 times likely as girls to develop the medical condition, says research.
While commenting on the study, fertility doctors said that the problem of sex preference is the tip of the iceberg with a huge range of tests becoming available, the Sydney Morning Herald reported.
Mark Bowman, director of the fertility company Genea, said that his firm has conducted over 100 cycles of "pre-implantation genetic diagnosis" this year alone, mainly for conditions like cystic fibrosis.
In a way these tests are the ultimate preventative medicine, Bowman said.
Guidelines provided by the National Health and Medical Research Council said that although sex selection is not allowed, it can be done to prevent the spread of a "serious genetic condition".
Bowman added that in about 1 in 20 cases parents undergo a cycle of pre-implantation diagnosis just for sex selection to avoid having another autistic child.
But some couples also choose sex selection for controversial reasons, such as depression and attention-deficit hyperactivity disorder.