High fertility rates cause high birthrates, which contribute to the high fetal mortality rate. Abnormal sperm increases, infertility rises, and birthrates decline. Demographers have put forward several factors behind high birthrates among Muslims in India. However, other sociologists point out that religious factors can explain high Muslim birthrates. These are the first and only documentaries on the worldwide decline in birthrates. He asserted that Muslims were replacing white people by using birthrates as a demographic weapon. Geldof asked countries to lower their birthrates to lessen the burden on the environment. At the same time birthrates amongst whites have fallen below replacement level. Birthrates fell everywhere, as children were postponed until families could financially support them. The birthrates fell everywhere, as children were postponed until families could financially support them. The Nazi Party wanted to increase birthrates of those who were classified as racially elite. Comprehensive sexual education on the other hand leads to a reduction in teenage birthrates. Most of the drop has been due to the fall in birthrates. " Tanton was concerned that US birthrates had dropped "below replacement level. Pierre Laplace compares the birthrates of boys and girls in multiple European cities.