Number of children and child mortality: Bluhm adds:—"Figure 1 shows in Curve A the influence of the duration of breast feeding; in Curve B influence of numerical position of birth on the mortality of the infant. The very divergent course of the two curves expresses the very different influence of both these factors on mortality; the latter is almost exclusively dependent upon the length of suckling, and shows corresponding with its increase a continuous and steep decline down to 1.46% from a maximum number of 35%. The very slight increase of the mortality of children suckled for six weeks compared with those who have not been breast fed at all is immaterial (35.55% against 35.28%). These figures prove only that breast feeding up to six weeks does not give the child any protection against fatal diseases. The influence of the birth number hardly makes itself felt up to the seventh child, only from the eighth onwards the power of resistance decreases continuously but not nearly to the same degree in which it grows with the length of breast-feeding (greatest difference only 21%). Curve B shows a materially different course from that of similar curves by other authors, for instance—from Geissler's well-known curve, dealing with Saxon miners, in which not only the first born show up less favourably than the second and third born, but in which, from the fourth child on, the mortality increases rapidly. The economical condition of both groups being similar (85% of Baum's families had a maximum yearly income of £75), it is highly probable that the difference in the curves arises from different methods of infant feeding. In the Rhine provinces, as is also proved by Baum's figures, the feeding is good; in Saxony, however, it is notoriously bad. The co-relation of infant mortality with infant feeding is very clearly illustrated in Figures 2 and 3, the former shows the influence of the length of suckling on the mortality of the children classed in order of birth, the latter the influence of the order of birth in connection with different lengthed periods of suckling. The extraordinarily regular course of all the nine curves in Figure 2 and the extremely irregular course of the six top curves in Figure 3 are very striking. From these figures it is shown that the first, second and third born if breast-fed for a short time only, or not at all, are subjected to much greater risks than the eighth, ninth, tenth or later children, suckled for a sufficient length of time (maximum difference 1 to 42). In the curve showing the children who were breast fed for 39 weeks (Figure 3), the influence of the high birth number shows only to a very small degree."
Number of children and capacity for breast-feeding. Concerning this it is remarked: "The upper curve shows what percentage of children had to do without breast feeding, and the lower one how many enjoyed the sufficient period of 39 weeks of breast-feeding. Though Baum's figures are only intended to deal with the number of cases of breast feeding and not with its duration, and though no difference is made between exclusive and partial breast feeding, yet some conclusions may be drawn with regard to suckling capacity. In a district where breast feeding is as general as it is in the one examined into here, the number of women who voluntarily renounce every attempt at suckling must necessarily be small. The curve dealing with the children who had no breast feeding at all is therefore likely to give a fairly correct picture of the absolute or primary incapacity for suckling on the mother's part; absolute incapacity does not of course mean that the mother could not produce a single drop of milk, but that she does not produce enough to satisfy the child, and therefore must resort to artificial feeding. As a period of 39 weeks' feeding, even if only partial, points to a good capacity, the lower curve may also be taken as an expression of feeding ability. A comparison of both figures illustrates that the milk production after the first birth is smaller than after the following ones, and that beyond the eighth birth, it decreases materially and continuously, probably in consequence of the exhaustion of the maternal organism."
The habit of breast-feeding as running in families and infant mortality. With this goes the following explanation: "The two figures illustrate the proportion of mortality of the infants in 143 bottle-feeding families and 376 breast-feeding families of the first order. As the line could not be drawn very sharply, and as in the bottle-feeding families there had to be included those in which as an exception one or other child was suckled for a few days or perhaps for a week, one can see in these groups only the expression of the habit, but not the power of suckling. Both figures illustrate the largely avoidable sacrifice in young lives which still goes on through a want of knowledge and of feeling of responsibility towards the coming race. With the absence of breast-feeding the unfavourable influence of a very large number of children becomes much more apparent; whereas in breast-feeding families the difference in the mortality between medium-sized families (four to six children) and very large families (above ten children) amounts to only 1.39%, it reaches 12.90% with the non-suckling families. Here, if the number of children surpasses ten, nearly every second child dies in the suckling age, and amongst thirteen families there is not a single one which has not lost a child in that period, whereas in breast-feeding families of the first order, with the same large number of children, only every thirteenth child died in infancy, and of sixteen families seven (= 43.75%) lost no infant." The same material is treated in a different way by Dr. Marie Baum, of Dusseldorf, in Figures C 63-66.
As the length of the period of suckling of the preceding child increases, there is a constant and rapid decrease in the number of children who are born at intervals of less than one year. If the preceding child was not breast-fed a new birth occurred before the expiration of one year in 9.6 cases out of 100. With a suckling period of one-half to three-quarters of a year of the preceding child, this figure is reduced to 1.8 per cent., and after a still longer suckling period to 1 per cent. Out of one hundred mothers who have only partly or not at all suckled the preceding child, seventy must count on a fresh birth within a period of 13/4 years. If the preceding child was suckled for at least 39 weeks, only thirty-eight, and with a suckling period of more than a year only twenty mothers have to reckon on a fresh birth within 13/4 years.
Dependence of Infant Mortality on the Duration of Breast-Feeding and the Length of Time Intervening Between Successive Births.
Figure C 63.