Declining male births in Germany before and after reunification.

Male births occur 3% in excess of female births in mammals in a ratio (M/F) of 0.515. Many factors have been shown to influence this, including socioeconomic deprivation. This paper reviews live birth data for Germany over the period 1946-2009, and identifies secular trends in M/F pre- and post-reunification. The null hypothesis is that there were no differences between East and West Germany, geographically or temporally, before and after reunification. Annual data on male and female live births were obtained from the Human Mortality Database and analyzed with contingency tables. These data were available separately for East and West Germany (1950-1989). There was a significant decline in M/F in both German Republics overall and before reunification (p<0.0001). No decline was present after. Pre-reunification, West Germany had a lower overall M/F than East Germany (p=0.001). In conclusion, a declining M/F has been shown in many countries over the past decades. The two German Republics' M/F fell prior to reunification and the economic collapse of East Germany. Contracting societies that offer poor socioeconomic conditions (such as the communist former East Germany) may result in a decrease in M/F, but this is not reflected in the data, which show that M/F in West Germany prior to reunification was lower than in East Germany. This is not explicable with the contracting economies hypothesis; other and as yet unknown influences may have modified M/F trends anticipated by known variables.