Summary:Data from 7045 subjects were examined. The main groups consisted of the following in-and outpatients: 1414 neonates, 2554 children and adolescents (1336 males, 1218 females), 1209 women directly postpartum, 786 non-pregnant women and 1090 men aged between 18 and 100 years of age. Unless otherwise stated, persons were under medical observation or therapy.The results were obtained over a three-year period using an in-house immunolurninometric assay specific for apolipoprotein(a) using two polyclonal antibodies and a single lot of reagents to allow for comparability of results.Girls aged between 10 and 12 years of age had significantly higher serum lipoprotein(a) (median 124 mg/1) levels than boys (median 88 mg/1) of the same age (p < 0.05 -Mann-Wliitney U-test). Post-pubertal lipoprotein(a) concentrations were not significantly different from pre-pubertal levels. Between the ages of 0-9 and 13-17 years there were no statistically significant sex-linked differences in serum lipoprotein(a).In adults, lipoprotein(a) serum levels were significantly higher in women (median 163 mg/1) aged between 50 and 59 years, when compared with men (median 128 mg/1) of the same age group (p = 0.05 -Kruskal-Wallis one way ANOVA followed by the Nemenyi test).There was no significant difference in serum lipoprotein(a) concentrations between healthy women (median 91 mg/1), women direct postpartum (median 116 mg/1) and in-patient women (median 117 mg/1) aged between 18 and 41 years of age (p = 0.11-0.96). There was no correlation between maternal lipoprotein(a) and birth weight in mature newborns (r = -0.028-0.085).The results may indicate a direct influence of gonadotropins at puberty and during the menopause which cause an increase in serum lipoprotein(a) concentrations.