We cannot wonder at this great frequency of sterility in obese women when we remember that, apart from the menstrual deficiencies which so commonly accompany this disorder of nutrition, obesity is apt to entail many other disorders of the reproductive organs, as for instance a morbid state of the uterine and vaginal secretions, chronic metritis, and displacements of the uterus; still, it cannot be denied, that in many instances we are unable in such obese women to detect any disorder of the reproductive organs competent to account for the sterility, and we must therefore assume that the excessive development of fat has some direct influence in preventing ovulation, or at least that it in some way exercises an unfavourable influence upon the reproductive process.
That excessive obesity hinders fertility, is shown by experience both as regards the vegetable and the animal kingdom. All animal-breeders are familiar with the fact that undue production of fat limits fertility. Thus, equally in the case of turkeys and in the case of the common fowl, if the hens are overfed and become fat, they cease to lay.
Hippocrates already indicated obesity as a cause of sterility. Writing of the wives of the Scythians, he pointed out as a proof that their excessive obesity was the cause of the sterility from which they commonly suffered, the fact that their female slaves, who were thin, were readily impregnated by intercourse with the Scythian males. The oft repeated dwindling and disappearance of ruling families in India and in Egypt, has doubtless in part depended upon the extreme obesity of the female consorts of such rulers.
In many instances, indeed, a great accumulation of fat on the front of the abdomen and in the vulva, suffices to cause a simply mechanical hindrance to the proper performance of a fertilizing coitus. It is possible also that the phlegmatic temperament of very fat women is a contributory cause to their sterility—if indeed it is in general true that frigidity during sexual intercourse is unfavourable to conception, as is expressed by the old proverb, quo salacior mulier, eo foecundior. It is unquestionable that in very obese women sexual sensibility is commonly greatly deficient, and that their husbands often complain of their coldness and lack of passion. In several cases that have come under my observation, dyspareunia occurred in obese and sterile women.
The dependence of sterility upon obesity is often proved in the most striking manner ex juvantibus. A “cure” for the reduction of fat often results favourably in respect also of rendering the woman who undergoes it readily impregnable—a result by no means ardently desired.
It must also be pointed out that very obese women form a considerable section of those suffering from only-child sterility, and this largely in consequence of their strong predisposition towards abortion. As the impregnated uterus enlarges, the space for its accommodation is insufficient, owing to the great development of the panniculus adiposus, and thus obesity, like intra-abdominal tumour, predisposes to abortion. The excessive accumulation of fat within the abdomen, by exercising pressure upon the inferior vena cava or on its principal tributaries, hinders the venous return, and gives rise to a chronic stasis in the uterine bloodvessels, those alike of the muscle and of the mucous membrane.
Notwithstanding the fact that sterility is so common in very obese women, the fact remains that some such women are remarkably fertile, and have very large families indeed.
Towers-Smith, Duke, and Rodriguez, who have recently all been engaged in examining the relations between obesity and sterility, agree in asserting that sterility due to obesity may be cured by dietetic treatment for the relief of the primary disorder of metabolism.
Though menstruation is usually deficient or absent in obese sterile women, and though it is commonly supposed that amenorrhœa implies sterility, it is necessary to point out that whilst failure of menstruation is a frequent and important sign of suppression of ovulation, it by no means invariably has this significance. It is an established fact, and one borne out by my personal experience, that women who have never menstruated have nevertheless become pregnant; others, again, have become pregnant although they have ceased to menstruate for several years, and this has even occurred in women at a comparatively advanced age. Hence, from the fact that amenorrhœa exists, we cannot with certainty infer that a woman is sterile. Moreover, we must remember that physiologically amenorrhoeic women often enough conceive—during lactation. Although we hold the opinion that there is an intimate connexion between ovulation and menstruation, yet it is always possible in cases in which menstruation fails to occur, that ovulation has taken place, but that the stimulus which that process has exercised upon the reproductive organs has been insufficient to give rise to the customary flow of blood.
The following remarkable case came under my own observation: Mrs. B., 26 years of age, had lived in sterile wedlock for six years, had never menstruated, nor had she ever had any sanguineous discharge from the genitals. The body was delicately formed, the breasts were fairly well developed, the external genital organs showed no abnormality. For some weeks before consulting me, this woman, hitherto childless, and living in regular sexual intercourse with her husband, had noticed a remarkable enlargement of the abdomen. Another medical man whom she had consulted had diagnosed ovarian tumor and had urged operation. A more careful examination of the pelvis showed, however, that the woman was in the sixth month of pregnancy, a diagnosis which was duly confirmed by the delivery of a full-time child. In another of my cases, a woman married at the age of 45 years, having ceased to menstruate two years previously. She became pregnant and gave birth to a child in quite normal fashion. The following instructive case also came under my own observation: The wife of one of my colleagues, living in sterile wedlock for 17 years, extremely obese, had since puberty menstruated but scantily and with great irregularity. The menstrual interval was several months, and when the discharge did appear, it was pale in colour and small in quantity; it lasted moreover but a day or two. Last winter, the flow as usual failed to appear for several months, and since the woman had at the same time become fatter than ever, Turkish baths and energetic muscular movements were prescribed. The result of this treatment was a striking one—abortion. After 17 years of marital intercourse she had for the first time become pregnant.