Time Trends in Human Fecundability in Sweden.
BACKGROUND:: Trends in biologic fertility are elusive. Possible negative trends in male reproductive health are still debated, and their effect on human fertility might be negligible. Time-to-pregnancy (TTP) is a functional measure of couple fecundability. METHODS:: We analyzed data on TTP among 832,000 primiparous women 20 years of age and older in the nationwide Swedish Medical Birth Registry fr
