Timing of puberty and fetal growth

Abstract

Children born small for gestational age (SGA: birth weight or birth length more than 2 standard deviations below the mean score) are at a higher risk of perinatal morbidity and mortality and of a number of chronic diseases in later life such as hypertension, decreased insulin sensitivity, diabetes mellitus type 2 and an increased risk of cardiovascular disease. The programming of the endocrine axes occurs during critical phases of fetal development and might thus be affected by intrauterine growth retardation. Studies in Northern Spanish adolescent girls have indicated associations between reduced fetal growth and the occurrence of precocious adrenarche, pubarche, hyperandrogenism, polycystic ovary syndrome (PCOS) and hyperinsulinism. These findings have attracted much attention because it might have serious consequences in later life. However, hyperandrogenism and precocious pubarche were not confirmed in a large Dutch study in short children born SGA. Two studies reported a lower number of follicles in the ovaries in girls born SGA, which might have an impact on fertility. Clearly, further studies are required before definite conclusions can be drawn. There are still only limited data concerning the timing of puberty in children born SGA. Most studies indicate that these children start their puberty at a normal age but relatively early within the normal range. Age at menarche seems comparable with controls. Data on duration of puberty, influence of puberty on attainment of adult height, peak height velocity during puberty and fertility are not yet known.