Japanese researchers have found that climate change could affect the ratio of human males to females in some countries.
The study by M and K Health Institute in Ako was done on recent years, and recorded nearly 90,000 newborns and about 1,000 fetal deaths per month in Japan. The scientists found the ratio of male to female babies born in the country had been decreasing, meaning there had been fewer and fewer male babies born relative to the number of female babies born, Live Science reported.
The researchers considered fetal deaths to be those that were spontaneously aborted (or miscarried) after 12 weeks of pregnancy.
However, the new study only found an association, and could not prove that the climate changes were responsible for the change in sex ratio in Japan. Other factors, such as pollution and toxins in the environment, may affect sex ratios.
The study came out in an issue of the journal Fertility and Sterility.