[Fertility survey. Approximation to normal values]

To determine the fertility data in Aragón, Spain.

A survey was conducted in several companies during 1997 and 1998. Participation in the survey was optional, participants were not identified and a table of random figures was utilized. Error 2 +/- 2.98, 95% confidence interval, P = Q = 50%.

139 employees participated in the survey; 94% were male, 6.4% were single, 87.7% married, 5.7% had a stable partner, 12.3% had higher level, 53.6% medium and 34% elementary level education. Mean number of children per couple was 1.7 and mean number of children desired was 1.9. Mean time from decision to have children to pregnancy was 4.5 months. Mean age at conception of the first child was 28 years for the men and 25 years for the women. One of the partners was employed in 42.7% of the cases. Mean working hours was 8.3 and mean number of years in the same job was 14.5. Twenty-one percent considered they were exposed to toxic substances. Mean hours of sleep was 6 hours, 35% took warm baths and 24.4% used tight-fitting underclothes. Ninety percent drank alcohol and/or coffee mild to moderately and 50% were smokers. No significant differences were found in the number of children according to level of education, type of work or if one of the partners or both were employed. A clearly negative correlation was found between the year of birth and the number of children desired.

In Aragón, the birthrate trend remains low and does not appear to be influenced by the economic level, life style, type of job or whether or not both partners are employed.