Human fertility does not decline: evidence from Sweden

Objective: To assess changes in human fertility over time. Design: Time-trend analyses and age-period-cohort modeling. Setting: Sweden , 1983-1993. Patient(s): All primiparous women aged greater than or equal to 20 years du ring the study period. There were 401,653 women who were identified through the nationwide Medical Birth Register. Intervention(s): None. Main Outcome Measure(s): Risk of subfertility, defined as greater than or e qual to 1 year of involuntary childlessness. Result(s): Subfertility problems decreased dramatically over successive mat ernal birth cohorts. Further, the risk of subfertility increased with age a nd decreased with increasing formal education. Conclusion(s): A decrease in male fertility cannot be ruled out on the basi s of these results, but if present, it is minor and totally outweighed by o ther favorable developments. As the main explanation for our findings, we p ropose a decrease in the prevalence of secondary subfertility as a result o f the eradication of gonorrhea. (Fertil Steril(R) 1999,71.1066-9. (C) 1999 by American Society for Reproductive Medicine.).