Month of birth and gametopathy

Abstract

Monthly variations in the incidence of births of 441 patients with Down's syndrome, 317 patients with Klinefelter's syndrome, and 126 patients with Turner's syndrome were studied. These three chromosomal aberrations showed almost identical seasonal variation with two maxima, a greater maximum in the period February to May and a smaller one in September. These fluctuations synchronous with those of the “normal” birth curve, but have a greater amplitude. To explain the variations, the following hypothesis is proposed: Seasonal fluctuations in the “normal” conception curve are caused by two basic oestric patterns, of which a phylogenetically younger (polyoestrus) is superimposed upon the phylogenetically older one (mono‐ or dioestrus). The latter is influenced by climatologic factors. The seasonal fluctuations in the “normal” conception curve can be explained by alternating periods of normal, i.e. ovulatory, and of disturbed, i.e. anovulatory, cycles. The increase of “pathological conceptions” during spring and autumn and the crease during winter and summer are caused by interference of the two basic oestric patterns. Such interference might retard the preovulatory or intrafollicular ripening of the egg cell, resulting in overripeness ovopathy. In addition, spermatopathy, too, could be influenced by climatalogic factors. Birth curves of parents of patients with Down's syndrome may suggest a constitutional factor, predisposing to “pathologic conceptions”.