Congenital Rickets with Maternal Pre-Eclampsia

Rickets: Historical, Epidemiological, Pathophysiological, and Pathological Perspectives

Rickets was a common metabolic disease of bone a century ago in Europe, North America, and East Asia (mainly due to vitamin D deficiency) but was largely eradicated in growing children by use of cod liver oil and the introduction of vitamin D fortification of milk in the 1930s in the United States. Vitamin D deficiency (VDD) remains the most common form of metabolic bone disease that is entirely preventable and treatable. Historically, rickets has appeared in sporadic epidemics and, despite the introduction of numerous preventive strategies, VDD has remained a global health problem amongst children. Moreover, developed countries such as Canada, Australia, the United Kingdom, and the United States have not been exempt from this. The radiological and histological features of rickets are both distinctive and characteristic and they reflect the underlying pathophysiological issue of decreased mineralization of bone as a result of VDD. The radiological features include 1) metaphyseal cupping and fraying, 2) poor mineralization of epiphyseal centers, 3) irregular and widened epiphyseal plates, 4) increased distance between the end of shaft and epiphyseal center, 5) cortical spurs at right angles to the metaphysis, 6) coarse trabeculation, and 7) periosteal reactions. Fractures may also be evident. The histological features of rickets reflect the failure of cartilage to mineralize and undergo resorption. This results in 1) disordered proliferation of chondrocytes in the hypertrophic zone secondary to a lack of apoptosis, 2) loss of the columnar arrangement of chondrocytes that results in thickening and disorganization of the hypertrophic zone, 3) tongue-like projections of cartilage that extend into the spongiosa, 4) irregularity of the limit between the proliferative and hypertrophic zones, and 5) penetration of blood vessels into the hypertrophic zone. The case of a premature 3-month-old female infant, born in the winter months in the arctic region of Canada who died from a lobar pneumonia with an incidental finding of radiological and pathological evidence of rickets, is presented. The case is used to review the entity of rickets from historical, pathophysiological, radiological, and histological perspectives.

Prenatal and infant predictors of bone health: the influence of vitamin D

Vitamin D is essential for the health of pregnant women and their infants. Vitamin D insufficiency and deficiency during pregnancy are reflected in lower maternal weight gain and biochemical evidence of disturbed skeletal homeostasis in the infant, with, in extreme situations, reduced bone mineralization, radiologically evident rickets, and fractures. Populations at risk for vitamin D deficiency are those for which, for environmental, cultural, or medical reasons, exposure to sunlight is poor and the dietary intake of vitamin D is low. The infants born in such populations have low vitamin D stores and may receive little additional vitamin D if they are breast-fed without supplements for long periods. In the short term, lack of vitamin D supplementation in infancy leads to biochemical disturbances, reduced bone mineralization, slower growth, and eventual alterations in bone shape and increased risk of fracture, the hallmarks of rickets. In the longer term, lack of vitamin D supplementation may result in reduced bone size and mass during childhood and an increased risk of type 1 diabetes mellitus. Clear recommendations are needed regarding the intake of vitamin D during pregnancy and infancy. Such recommendations should be based on functional outcomes, rather than biochemical measurements, so that the medical problems resulting from the lack of this essential nutrient can be overcome.