Human fertility does not decline: evidence from Sweden.
OBJECTIVE
To assess changes in human fertility over time.


METHODS
Time-trend analyses and age-period-cohort modeling.


METHODS
Sweden, 1983-1993.


METHODS
All primiparous women aged > or =20 years during the study period. There were 401,653 women who were identified through the nationwide Medical Birth Register.


METHODS
None.


METHODS
Risk of subfertility, defined as > or =1 year of involuntary childlessness.


RESULTS
Subfertility problems decreased dramatically over successive maternal birth cohorts. Further, the risk of subfertility increased with age and decreased with increasing formal education.


CONCLUSIONS
A decrease in male fertility cannot be ruled out on the basis of these results, but if present, it is minor and totally outweighed by other favorable developments. As the main explanation for our findings, we propose a decrease in the prevalence of secondary subfertility as a result of the eradication of gonorrhea.
Akre
O
O
Department of Medical Epidemiology, Karolinska Institutet, Stockholm, Sweden. olof.akre@mep.ki.se
Cnattingius
S
S
Bergström
R
R
Kvist
U
U
Trichopoulos
D
D
Ekbom
A
A
D000328:Adult; D000375:Aging; D004522:Educational Status; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology*; D008297:Male; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors