A wife who has had children and ceases to conceive for three years will probably bear no more.

When marriages are fruitless, the wife is almost always blamed; but it is by no means the wife that is always at fault; many husbands are absolutely sterile.  Every man is not prolific who enjoys good health and is vigorous.  Gross states that in one case out of six the sterility was due to the male.  Kehrer, after a series of carefully conducted experiments, has arrived at the conclusion that in at least a third of the cases of sterile marriages the husband was the party at fault, and that gonorrhea was the cause of the barrenness.

Venereal diseases have their share of influence, and the gonorrheal infection is a potent cause of sterility.  It is by no means proved that syphilis has any unfavorable influence on conception, though abortions due to this are frequent.

Gonorrhea often prevents conception by the inflammation traveling up the womb, and along the Fallopian tubes to the ovaries, whose covering is rendered thick and dense, so that the ovum cannot escape, or if it does, the fimbriated end of the tube is so agglutinated that it cannot grasp the ovum.

Alcoholism is considered a cause of sterility.  It evidently does diminish the sexual potency in the male, and for this the female is often blamed.

It does not follow because a woman has not given birth to a child that she has not conceived.  The life of an infant for a long time after birth is a frail one, and before birth its existence is extremely precarious; it often perishes a few days after conception.  A period coming on a few days late, and at the same time one which is unusually profuse, is the only evidence which the young wife may have of an abortion.  Among prostitutes, the frequent delay of menstruation, then abundant hemorrhage, is in many cases only habitual abortion, and leads to changes in the generative organs which must result in sterility.  A tendency to miscarriage may therefore be all that stands in the way of having a family; this can frequently be remedied.

Sexual incompatibility is well known to exist; prominent examples being Augustus and Livia; Napoleon and Josephine.  It is also a well-known fact that frigidity is a cause of barrenness.  A short separation of husband and wife is often salutary in its influence upon fertility.

It is a well-established fact that the time immediately before the period, but still more that immediately following the period, are the most favorable times for conception to take place; the remaining quiet in bed of the woman after the generative act is also favorable to conception.