Physical growth, age at menarche and age at first union in rural Guatemala

A Systematic Literature Review of Factors Affecting the Timing of Menarche: The Potential for Climate Change to Impact Women's Health

Menarche is the first occurrence of a woman’s menstruation, an event that symbolizes reproductive capacity and the transition from childhood into womanhood. The global average age for menarche is 12 years and this has been declining in recent years. Many factors that affect the timing menarche in girls could be affected by climate change. A systematic literature review was performed regarding the timing of menarche and four publication databases were interrogated: EMBASE, SCOPUS, PubMed, and Cochrane Reviews. Themes were identified from 112 articles and related to environmental causes of perturbations in menarche (either early or late), disease causes and consequences of perturbations, and social causes and consequences. Research from climatology was incorporated to describe how climate change events, including increased hurricanes, avalanches/mudslides/landslides, and extreme weather events could alter the age of menarche by disrupting food availability or via increased toxin/pollutant release. Overall, our review revealed that these perturbations in the timing of menarche are likely to increase the disease burden for women in four key areas: mental health, fertility-related conditions, cardiovascular disease, and bone health. In summary, the climate does have the potential to impact women’s health through perturbation in the timing of menarche and this, in turn, will affect women’s risk of disease in future.

Physical growth and development of the malnourished child: contributions from 50 years of research at INCAP

This paper reviews the main findings and policy implications of 50 years (1949-1999) of research conducted by INCAP on growth and development. Topical areas reviewed include a) maternal size and birthweight and the causes of intrauterine growth retardation (IUGR), b) patterns and causes of postnatal growth retardation, c) the relative importance of genetics and the environment in explaining differences in growth among populations, d) the implications of being small, for both children and adults, e) bone growth and maturation and dental development, f) menarche, and g) methodological contributions such as anthropometric reference data, quality control of data collection, development of risk indicators and use of anthropometry in nutrition surveillance systems. Key contributions to knowledge by INCAP include a) characterization of growth failure and maturational delays as mainly occurring during the intrauterine period and the first 3 years of life b) clarification of the role of small maternal size and of inadequate dietary intakes during pregnancy as major causes of intrauterine growth failure, c) evidence that diarrheal diseases and poor dietary intakes are the principal causes of growth failure in early childhood, d) demonstration that environmental factors related to poverty, and not genetic or racial ancestry, account for most of the differences in growth between populations, e) evidence that growth failure predicts functional impairment in the child as well as in the adult andf) demonstration that nutrition interventions are effective in preventing growth failure and its consequences, if targeted to needy women and young children. INCAP's work has contributed knowledge that has informed and improved policies and programs aimed at overcoming maternal and child undernutrition and promoting optimal growth and development.

INCAP studies of endemic goiter and its prevention

The high prevalence of goiter among adults in its member countries of Central America and Panama was observed as soon as INCAP began field studies. This led to systematic studies of goiter in schoolchildren in all of the countries as described, beginning with Guatemala where the rate was 38% nationally. However, efforts to eliminate the consequences of iodine with iodized salt using the water soluble potassium iodate and a process that had proved successful in Switzerland and the United States could not be used with the crude moist salt of the region. INCAP identified potassium iodate that is insoluble in water, and in four schools (two each in El Salvador and Guatemala) proved that the iodine in this compound was as available as that in potassium iodate. It remained evenly distributed in moist salt. When added to salt in Guatemala, goiter rate dropped to 15% in four years and less than 5% in eight years. Compulsory iodation of salt in other developing countries followed with comparable results. This method is now used in worldwide campaigns against iodine deficiency in developing countries.

Early childhood nutrition, education and fertility milestones in Guatemala

Data on fertility milestones were collected in 1994 and linked to information collected in a trial conducted in eastern Guatemala between 1969 and 1977, to examine whether early childhood nutrition was associated with the timing of fertility milestones. In the original trial, two pairs of villages were randomly allocated to receive either a high energy, high protein supplement (Atole) or a low energy, no-protein supplement (Fresco). Mean age at follow-up was 23.47 y (n = 240). About 62% of women had experienced first birth (median age at first birth = 19.83 y). The median intervals from menarche to first intercourse and from first intercourse to first birth were 5.67 and 0.95 y; they were 1.68 and 0.06 y shorter, respectively, for the Atole group than for the Fresco group. Women who had received Atole in utero and/or during early childhood experienced earlier milestones even after adjusting for socioeconomic status (SES), education and age at the prior event. Median age at first birth was 1.17 y earlier for the Atole group. Better growth during early childhood (not severely stunted) led to earlier milestones (median age at first birth was 1.04 y earlier), primarily among women with illiterate fathers. Completion of primary school significantly delayed fertility milestones; the median age at first birth was 4.27 y later for those who completed primary school compared with those who did not (P < 0.05). In sum, improved nutrition during early childhood results in earlier fertility milestones, but the effects of schooling in delaying fertility milestones are greater in magnitude. Intervention programs that improve early childhood nutrition should be accompanied by investments in education that ensure that girls complete primary school.