Inability to have children, to reproduce; sterility. The term infertile is usually applied to individuals who are relatively unable to have children, but who may (or may not) be able to reproduce after treatment or under different conditions. The term sterile is often reserved for absolute inability to have children, although the two terms are often used interchangeably.Approximately one marriage in seven is childless, and in most of these cases the couple would like to have a child but are not able to do so. Studiesshow that pregnancy is achieved within three months in about 60 per cent of couples who wish to have children; if they are unsuccessful for a year, a fertility examination of both husband and wife is usually recommended. Contrary to popular opinion, which assumes that “barrenness” is wholly due to the wife, about 40 per cent of cases are due to the husband—and in some cases the fertility level of both partners may be low. Most of the cases are physical in nature, but there is considerable evidence that psychological factors may also be involved in childlessness, and in these cases infertility may be classified as a psychophysiologic or psychosomatic disorder of the genitourinary system.Among the most important physical causes and conditions in women are: age—the chances of fertility drop from 96 per cent to 85 per cent between the ages of 20 and 35; infections following induced or spontaneous abortion; infrequent intercourse due to pain (50 per cent of women who suffer from painful intercourse are childless); infrequent intercourse due to unconscious fear of pregnancy; scars or adhesions left by abdominal operations such as appendectomies; inadequately treated venereal disease (gonorrhea or syphilis); glandular disturbance associated with late menstruation or excessive bleeding and pain; and injured or wrongly tilted cervix (the entrance to the uterus). A number of these conditions may interfere with ovulation or produce a blocking of the Fallopian tubes. Common causes in the male are: mumps contracted after puberty; glandular disturbance producing undescended testicles (cryptorchism) in childhood; venereal disease; low sperm production, or an excessive ratio of abnormal sperm.In many cases—at least 50 per cent —the physical causes of infertility can be corrected. In the woman, ovulation can often be restored and miscarriages prevented by hormone injections; blocked tubes can be reopened with fluid or carbon dioxide (the Rubin procedure); scars and adhesions often respond to heat treatment, infections respond to antibiotics, fibroid tumors and polyps to surgery, and a tilted cervix may be corrected by manipulation or a ring. In men only one in ten infertility cases is found to be totally lacking in sperm production—that is, completely sterile; there is a good chance of overcoming insufficient or faulty sperm production through thyroid treatments, diet, vitamins, and rest; and difficulty in delivery of sperm can sometimes be corrected by surgery.The psychological aspect of infertility is receiving increased attention today. At present emotional factors appear to apply more clearly to women than to men, and it is an accepted fact that these factors may be involved in both their ability to conceive a child and to carry it to term. In the case of men, the relation between psychological factors and fertility has been less clearly established—yet it is significant that the Margaret Sanger Research Bureau reports that 25 per cent of couples who visit the clinic become fertile while the testing process is going on, and before any specific treatment is undertaken. It appears that the fact that they are openly facing the problem and facing it together reduces the tension, guilt, or anxiety to a point where the physical functions can return to normal. In many cases, too, one or both receive psychotherapy, and this treatment is frequently effective not only in increasing fertility but in overcoming the problem of miscarriage.Along these lines, English and Finch (1964) state: “Many women who have been childless for years for no demonstrable organic reason have conceived and borne a child after intensive psychotherapeutic measures. The latter has usually been undertaken for some other condition rather than for the infertility. It is also well known that women occasionally, upon assuming sterility after many years of lack of conception, adopt a child only to find themselves subsequently pregnant presumably because of a stirring of what must be called “the maternal instinct” within them. The degree to which this is psychological and endocrinological is debatable, of course, but it certainly would appear that there are strong psychological factors involved.” Likewise, Redlich and Freedman (1966) state, “Many infertile couples are fatigued and under stress when they have intercourse, and this may somehow have an untoward effect on fertility. At times, simple clarification may help to correct adverse habits and facilitate impregnation. In some, a more intensive psychotherapeutic effort may help to tackle the sexual difficulties or the unconscious motivation to avoid having children. Unfortunately, there are no controlled studies to demonstrate the role of psychogenic factors in sterility. Fertility after psychotherapy of husband and wife, or either one, has often been observed; whether this is the result of psychotherapy is difficult to establish. An interesting and not infrequent observation concerns previously infertile couples who had children of their own after adopting a child, which presumably produces a better attitude toward parenthood.”