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13 recordsLinked to original sources
PubMed1996

Ethnography of fertility and menstruation in rural Mexico.

In rural populations in Mexico, the system of ideas in relation to the reproductive cycle is built on a mestizo base, with pre-Colombian and Western elements. The objective of the study was the analysis of concepts and resources related to human reproduction in Morelos, in order to design a primary reproductive health care program. The use of ethnographic methods helped identify bio-cultural constructs on which the communities base their reproductive patterns. Our main research results reveal that these populations attribute great value to the extension of the family through descendants. Women's sexuality is directly linked to reproduction and blood is the supremely feminine substance. Great importance is consistently attributed to menstruation about which well-defined concepts exist in the community, where as pre-menarche changes are perceived as a state of bio-psychosocial maturity. Menarche beyond 14 years of age is considered abnormal and is attributed to an 'excess of cold' in the body, therapy is usually administered by traditional birth attendants. In the mythical explanations given for bleeding, the moon plays a fundamental role, as the first rupture of the hymen is attributed to it. A general lack of knowledge about ovulation and its relation to reproduction was observed, resulting in incorrect contraceptive practices.

Adolescent↗
PubMed1978

Hormonal correlates of normal and abnormal follicle growth after puberty in humans and other primates.

After the menarche, changing levels of gonadotrophins, prolactin and sex steroid hormones in peripheral blood are accompanied by ovulation and corpus luteum formation in one follicle, and atresia in the remaining follicles maturing during each menstrual cycle. Available evidence suggests that blood levels of steroid hormones reflect in large part the secretory activity of the ovary containing a pre-ovulatory follicle and most probably of that follicle itself (see Chapter 6). These steroid secretions and those of the corpus luteum coordinate hypothalamic-pituitary-ovarian function. Within the ovary, sex steroid hormones mediate effects of gonadotrophins and prolactin on follicle maturation and participate in determining the fate of individual follicles.

Animals↗
PubMedDate not supplied

Age at menarche: secular trends and association with adult anthropometric measures.

BACKGROUND: Age at menarche has been used as a marker of environmental conditions during childhood. Previous work has shown trends of decreasing age at menarche throughout the 19th century, but reported trends in the 20th century have been less consistent. The nature of the relationship between age at menarche and adult life anthropometric measures may be important in understanding the importance of this measure on disease in later life. AIM: To establish whether mean age at menarche changed during the first half of the 20th century, and to determine the nature of associations between age at menarche and anthropometric measures in young adulthood. SUBJECTS AND METHODS: 3433 female students, who were born between 1919 and 1952 and who attended health checks at the student health service of the University of Glasgow between 1948 and 1968. RESULTS: Mean age at menarche decreased from 13.2 years in the earliest born to 12.5 years in the latest born students. These results were not explained by changes in socio-demographic factors. Menarcheal age was positively associated with height and negatively associated with weight and BMI, results independent of socio-demographic and behavioural factors. CONCLUSIONS: The falling age at menarche described here may be related to nutritional influences in the first half of the 20th century. The influence of menarche on BMI in early adulthood may have important health consequences.

Adolescent↗
PubMed1998

Iron status, menarche, and calcium supplementation in adolescent girls.

The effects of growth, menstrual status, and calcium supplementation on iron status were studied over 4 y in 354 girls in pubertal stage 2 who were premenarcheal at baseline (x+/-SD age: 10.8+/-0.8 y). Girls were randomly assigned to placebo or treatment with 1000 mg Ca/d as calcium citrate malate. Anthropometric characteristics, bone mass, and nutritional status were measured biannually; ferritin was measured annually; and red blood cell indexes were determined at 4 y. The simultaneous effects of iron intake and menstrual status on serum ferritin, after change in lean body mass (LBM) was controlled for, were evaluated in subjects in the upper and lower quartiles of cumulative iron intake. The average maximal accumulation of LBM (386 g/mo; 95% CI: 372, 399) occurred 0.5 y before the onset of menarche. Change in LBM was a significant predictor of serum ferritin (P < 0.0001), with a negative influence on iron status (t ratio=-4.12). The 2 fitted mathematical models representing ferritin concentrations of subjects in the upper and lower quartiles of cumulative iron intake were significantly different (P < 0.018). The regression line of the ferritin concentration in menstruating girls with high iron intakes had a less negative slope than the line fit to serum ferritin concentrations in girls with low iron intakes (NS). Serum ferritin concentrations at 0, 1, 2, 3, and 4 y were not significantly different between groups. In addition, there was no significant difference between groups in any of the red blood cell indexes. In summary, growth spurt and menstrual status had adverse effects on iron stores in adolescent girls with low iron intakes (<9 mg/d), whereas long-term supplementation with calcium (total intake: approximately 1500 mg/d) did not affect iron status.

Adolescent↗
PubMed1999

A longitudinal study of serum ferritin in 319 adolescent Danish boys and girls examined in 1986 and 1992.

This study examined trends in iron status in adolescents. Serum ferritin was measured in 1986 and 1992 in 319 Danes (161 males) stratified into 5 groups: I. median age 9 yr in 1986 vs. 15 yr in 1992; II. 11 vs. 17 yr; III. 13 vs. 19 yr; IV. 15 vs. 21 yr; V. 17 vs. 23 yr. Males in group I demonstrated no change in ferritin or estimated iron stores in mg/kg; groups II-V displayed an increase in iron status parameters. All groups showed an increase in estimated total iron stores. Changes in iron status parameters were inversely correlated with height velocity in group III, and positively correlated with height velocity in group V. Females in age groups I and II demonstrated a fall in ferritin and estimated iron stores in mg/kg in association with menarche; values were unchanged in groups III and IV, and increased in group V. All groups showed an increase in estimated total iron stores. Changes in iron status parameters were inversely correlated with height velocity in groups I and II. In conclusion, ferritin levels in adolescents display great variation during growth spurt and at menarche. Changes in ferritin showed no consistent association with growth velocity. In both genders, estimated total iron stores increased with age.

Adolescent↗
PubMed1975

Implicit messages concerning menstruation in commercial educational materials prepared for young adolescent girls.

Interviews with young girls aged 9 to 18 revealed that commercial educational materials are an important source of information about menstruation. Although these materials are valuable educational supplements, they do not provide a complete, accurate, and realistic description of menarcheal changes and emphasize good hygiene rather than dealing with the young girl's emotional needs and anxieties. The authors stress the need for more research into the physiological, cognitive, and psychological changes during puberty and the obligation of parents, schools, and other social institutions to provide more comprehensive information to the maturing girl about the essential issues of pubertal development.

Adolescent↗
PubMedDate not supplied

Changes of recollected menarcheal age and month among women in Tokyo over a period of 90 years.

Data on the recollected age at menarche of 47,881 women born between 1881 and 1970 were examined. The mean menarcheal age had changed from 15.1 years in those born up to 1900 to 12.5 years in those born during the 1960s. The age at menarche differed according to the month of birth, and the pattern of average age distribution by month of birth was not the same when the year of birth was different. Among women born before 1955 the menarcheal age was earlier in those born in the summer. However, among women born after 1955, menarche occurred later when they were born in the summer. The monthly distribution of menarche had also changed during this 90-year period. Two peaks in April and August were prominent among those born up to 1960. A third peak in January became also apparent in those born after 1960.

Adolescent↗
PubMed1981

[Not Available].

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France↗