Sex Ratios at Birth and Environmental Temperatures


 The relationship between average monthly air temperature and sex ratios at birth (SRB) was analyzed for children born in Germany during the period 1946–1995. Both the absolute temperature and – more markedly – the monthly temperature deviations from the overall mean were significantly positively correlated with the SRB (P<0.01) when temperatures were time-lagged against the SRB data by –10 or –11 months. It is concluded that the sex of the offspring is partially determined by environmental temperatures prior to conception.

This is a preview of subscription content, log in to check access.

Author information



Additional information

Received: 26 August 1998 / Accepted in revised form: 18 February 1999

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lerchl, A. Sex Ratios at Birth and Environmental Temperatures. Naturwissenschaften 86, 340–342 (1999).

Download citation


  • Temperature Deviation
  • Absolute Temperature
  • Environmental Temperature
  • Monthly Temperature
  • Monthly Temperature Deviation