Women born during the summer end up having fewer children than those born at other times of the year, a study shows.

The research, involving 3,000 Austrian women, found that on average the number of children was lower for those of reproductive age born between June and August than for those born in other months.

July-born women had 0.3 fewer children than those born in December. Susanne Huber from the University of Veterinary Medicine in Vienna, Austria, who led the research team, said there could be many possible causes for the findings.

The research is published in the journal Human Reproduction.