Age of biological maturity of Malaysian girls by ethnicity.

PIP: This study estimates the age of biological maturity, defined as the end of adolescent sterility, of Malaysian girls by employing an indiredt methodology. Biological maturity usually occurs about 3 years after puberty. Adolescent subfecundity is due to anovulatory cycles or to short luteal phases among menarchial girls. In this study, age at biological maturity is estimated by considering retrospective fertility and family survey data on marriage, 1st birt, and contraceptive use. The waiting time for the biologically mature females to conceive is 3.0 months; 3.2 months among the Malays, 2.7 months among the Chinese, and 2.8 months among the Indians. The maximum age of attaining biological maturity is 20 for all ethnic groups except Indians (19 years). The maximum age is estimated by considering females whose 1st pregnancy ended in a live birth and who have been living most of the time with their husbands since marriage, with no contraceptive usage. The expected age of biological maturity at birth is 15.6 years; 15.3 years for the Malays, 15.4 years for the Chinese, and 14.8 years for the Indians. The means age of attaining biological maturity coincides with the expected age of attaining biological maturity at birth.^ieng

The effect of oral contraceptives in Malaysians: 1. iron metabolism and erythropoiesis.

PIP: Previous studies have suggested the possible involvement of oral contraceptives (OC) in enhanced red blood cell production (erythropoiesis). The present study attmepts to determine the effect of OC use on iron storage, as measured by serum ferritin, and on erythropoeitic activity in Malaysians. Health women of the 3 major Malaysian ethnic groups (Malays, Chinese, and Indians), all of whom were low-dose OC users, served as the study group. The findings confirm previous reports that serum iron levels are significantly increased in women taking OCs. Serum ferritin, a better measure of total body iron stores, dropped during the 1st 1-12 months of OC therapy. The drop was most pronounced at 4-6 months. However, by 1 or 2 years, the serum ferritin levels were comparable to those of the control group. Coinciding with the drop in serum ferritin was an increase in hemoglobin synthesis and erythropoiesis. These findings suggest that the initial drop in serum ferritin may be attributed to increased mobilization and utilization of iron as a result of increased erythropoiesis. This enhanced red blood cell production appears to be a consequence of OC therapy. After the 1st year, a new equilibrium is reached, at which the mean hemoglobin level, as well as total white blood cell and platelet count, is higher in OC users than in controls. Such changes have been shown to affect the flow properties of blood; further studies are needed to determine if these factors bear on the thromboembolic complications of OC use.^ieng