FREQUENCY AND CAUSES OF MULTIPLE PREGNANCY.
the term multiple pregnancy, we include all cases in which the uterus contains several foetuses instead of a single foetus. When there are two foetuses, twin pregnancy exists. We may also have triple, quadruple or quintuple pregnancies. Wappoeus noted, among 19, 698,322 confinements occurring in Germany, Belgium, Sweden, Denmark, Sleswig-Holstein, Ireland and Austria: Quintuple pregnancies have been observed by Hull, Chambon, Ken nedy, Ramsbotham and Cazeaux. MacClintock and Puech have seen them twice. The proportion of multiple pregnancies is not the same in different countries. The largest relative number is found in England. Thus, among 484,350 labors recorded in England, Germany, and France, there were 6,248 double, 78 triple and 4 quadruple pregnancies, which may be classified as follows: These differences have been referred to latitude, race, the influence of stature and large ovaries. These may have a certain importance, but heredity, and the multiparous state have a much greater causative in fluence. Double pregnancies are incontestably more frequent with multi par than with primipane. Lebel, whose work is based on observations made at this clinic, found, among 140 cases: primipane, 51, multipane, 89; Collins, out of 240 cases, primiparte, 72, multiparw, 168. Duncan states the proportions as follows: primiparaze, 45.90 per cent., multiparse, 54.10 per cent. The influence of heredity is still stronger, especially on the mother's side. Twin sisters often have twins, and we find, almost always, examples of multiple pregnancies among sisters, aunts, and cousins. The paternal influence must not, however, be denied, and the cases although less numerous, are equally striking. The most remarkable case is that of a certain Russian peasant who, having married twice, had eighty seven children by his two wives. The first wife had four quadruple, seven triple and sixteen double pregnancies. His second wife had two triple and six double pregnancies. As regards age, the sixty-one twin preg nancies observed by Kleinwachter, are thus classified: It is generally admitted that the causes of twin pregnancy are three in number. 1. Two Graafian follicles, either in the same ovary or in differ ent ovaries, mature simultaneously, pass through their evolution and each expel an ovum. 2. A single Graafian follicle contains, at the same time, two mature ova, which are simultaneously fecundated. 3. A single follicle contains a single ovum which possesses two nuclei.
Here arises a mooted question. We refer to super-fcetation, two varie ties of which are recognized, super-impregnation (super-fecundation), and super-fcetation proper. Now, although all authors admit the existence of super-fecundation, many deny the existence of super-fo3tation. The difference is, indeed, great. Super-fecundation, super-impregnation, is the successive fecundation of two ova belonging to the same period of ovula tion. These two ova are fecundated by sexual intercourse, practised, at different dates never far separated, by the same or by different persons. The most convincing facts bearing on this subject are furnished by cases in which negresses, having sexual relations with a white man and a negro, give birth to one mulatto and to one negro. Moreover, there are still
more striking cases where white women, having intercourse with one white and one black man, are delivered of one white and one mulatto child. These facts are confirmed by the experience of veterinary sur geons. The characteristic feature of super-fecundation is that the ova belong to the same ovulation. In super-fcetation two ova, belonging to different ovulations, are fecundated after intervals more or less pro tracted. In order, then, that super-fcetation may occur, it is necessary: 1. That ovulation occur at least once more after the first ovule has been fecundated. 2. It is necessary that the spermatic fluid, having reached the uterus which is developed by pregnancy, should pass between the serotina reflexa and the serotina vera—that is, that the two membranes be not yet united, and that the fluid should penetrate the Fallopian tube, and, arriving at the ovary, come in contact with the newly discharged ovule. The second condition is anatomically possible, since the two serotina are not united before the third or fourth month of pregnancy. The orifice of the tube also remains patulous until this. time. The per sistence of ovulation during pregnancy is denied by all authors. So long as it is not proven that ovulation may persist during pregnancy, we are not justified in admitting the occurrence of super-fcetation. The arguments advanced by the believers in super-fcetation do not seem conclusive to us. One of these arguments is based on the notable difference sometimes found in the weight of twins, born at the same time; another argument is based on the rarer, but still authentic, cases in which two living and viable children have been born at different and widely separated periods. The following are the intervals in some of these cases: four and one halt months, Marianne Bigaud: five and one half months, Benpite Franquet: five months, a woman of Arles: seventeen weeks, a case of Dimerbroeek: six weeks, a case of Lebas: four weeks, a case of Dr. Moebus: fifty-two days, a case of Thielmann: forty-two days, cited by Fordyce Barker: one .month, Giuseppe Generali. (Vide the thesis of Ganahl, Super-fcetation, Paris, 1867). But, as Depaul says, these observations are all incomplete, —all date from the last century, and do not offer sufficient guarantees as regards the examination of the children or of the mothers. One more argument is derived from the cases of double uterus, or bilocular uterus. Now this malformation has only been observed in two cases, those of Barker and of Generali, and, in the case of the woman Bigand, the uterus was single. We, therefore, follow the example of Depaul in requiring, before admitting the possibility of super-fcetation: 1st. The proof that ovulation may persist during utero-gestation. 2d. Cases observed by competent accoucheurs, and in which all the conditions pertaining to both mother and child are given in great detail.