on 11 March 2011, Japan experienced the strongest earthquake that claimed the lives of 16,000 people. 2900 missing, more than 6000 received various injuries and were a long time in hospitals, and hospitals. Areas of Miyagi, Fukushima, Iwate received the most damage and required a long recovery. After this incident reduced the number of newborn boys, notify gazety.
The study, conducted by Ralph Catalano, gave some food for thought. In fact, in areas that are maximally close to the epicenter of the earthquake, the percentage of newborn boys decreased by 2.2%, while in remote areas the figure has remained in place. This can be seen for the first time. Same jumps were observed in 2008 in the United States, immediately after the crisis.
The theory argues that the main cause of this phenomenon is stress during pregnancy and the violation of the proportions of boys and girls, which is already laid to the moment of conception. Both of these factors equitable involved in the formation jump.
Statistics show that the percentage of abortions and prematurity is higher among boys, so they more often suffer from perinatal problems. It is worth noting the level of the hormone gonadotropin - during pregnancy boy he is relatively lower, and because it prevents miscarriages in pregnant women.
Another reason is testosterone, which affects the production of sperm. During stress, the amount of this hormone decreases, and the number of sperm - cells carrying the Y-chromosome, which is responsible for the birth of boys.