Lead. Whereas the germ cells are well protected against many harmful influences from without which affect the soma of the mother, they and the fœtus produced from them suffer considerably from some. Amongst their deadliest enemies are certain poisons, and notorious in this respect is lead. Table C 98 gives two sets of statistics on this point, they justify the law in Germany, and in other States, forbidding female labour to deal with lead and lead-containing materials. Paul's figures, showing that lead poisoning of the father is also extremely adverse to the production of a healthy progeny, are remarkable.
Female Labour. A baneful influence on reproduction is brought to bear by the growing quantity of professional female labour away from home and by the economic emancipation of women. Evidence of this is given in Table C 99—"female labour and child mortality"—the data of which are taken from Prinzing's work. Infant mortality is higher the larger the percentage of females employed in factories during the child-bearing period. This is partly due to interference with breast-feeding and partly to the unfavourable influence on pregnancy.
Dr. Agnes Bluhm has given in Figure C 100 "Female Labour and Reproductive Activity," the statistics of Roger and Thiraux, as well as the results of the investigation of the Imperial Statistical Office on the "Relationship of illness and deaths in the Local Invalidity Fund for Leipzig and surroundings." Dr. Bluhm gives the following explanation: "The top figure on the left is based on material of the Local Invalidity Fund for Leipzig and surroundings, dealing with over a quarter of a million of women of child-bearing age. The distinction between obligatory and voluntary members makes possible the estimate of the influence of work continued up to the time of confinement, because the voluntary members receive the same weekly payments during confinement as the obligatory ones, and, consequently, a woman has no object in joining the voluntary insurance scheme except in order to secure rest before confinement, which they procure for themselves at their own expense and with the loss of their wages. (At that time the compulsory support during time of pregnancy did not exist.) It is to be noted that the voluntary members show ten times as many confinements as the obligatory ones."
"The left hand figure at the top shows that the women who work up to the time of confinement fall ill during their pregnancy twice as often, and have six or seven times as many miscarriages and premature births and 1.28 times as many cases of death in child-bed, as those who stop work for a more or less extended period previous to their delivery."
"The frequency of illness after childbirth is in both categories of women almost the same; but the duration of the illness beyond the period for which the legal subvention provides (13, 26, or 34 weeks respectively) is much greater in the case of the obligatory members who do not spare themselves before their delivery."
"Left hand figure at the bottom—the researches were made by Roger and Thiraux in a maternity home. A comparison is made between the women who entered the home only at the beginning of childbirth and those who entered during the last month of pregnancy or sooner. Premature birth occurs in nearly one-third of the cases among the former, but among the latter only one-eighth.
"Right hand figure at the bottom—dealing with the same material as the left hand figure below compares the weight at birth of the first, second and later born. The average weight of the former is 300 g. and that of the latter 341 g. higher with mothers who cease work two or three months before delivery, than with those who worked up to the last. Possibly this expresses in the main the different duration of pregnancy. The importance of the birth weight of a child for its further development is not to be underrated."