Premature labor in cases where the child is viable is produced by the same agencies that interrupt gestation in the early months. Obstetricians think that syphilis is the commonest cause of premature labor, and they estimate that from 50 to 80 per cent. of these premature births are due to syphilis. In a series of 705 fetal deaths in Johns Hopkins Hospital, 26.4 per cent. were due to syphilis. After syphilis the cause of premature labor next in frequency is nephritis with placental hemorrhages and infarcts. Twins are not seldom delivered prematurely because of lack of room in the uterus. For the same reason any tumor of the uterus or abdomen may cause an abortion. When successive pregnancies are interrupted prematurely the abortion is said to be habitual, and again the commonest cause is syphilis. In this disease, as the virulence of the infection decreases, the gestation is prolonged until a child is born infected with congenital syphilis. This child commonly dies, and later a child strong enough to live appears. Correct treatment of the parents will avert this slaughter of the innocents. Sometimes the syphilis is latent so far as clinical symptoms are concerned, but we may find a positive Wassermann reaction. Hubert reported[89] that 8.8 per cent. of 8652 patients in a clinic at Munich where all were subjected to the Wassermann test had latent syphilis, and in 52 per cent. of these cases in men, and 75 per cent. in women, the infection was altogether unknown to the patients. [89] _Münchener medizinische Wochenschrift_, lxii, 39. Chronic endometritis, where there is no syphilis, will permit habitual abortion, and each abortion makes the condition worse. Nephritis, diabetes, and other constitutional diseases cause habitual abortion. In the first two months of gestation the decidual fold which holds the ovum against the uterine wall is thick, vascular, and friable. The contracting uterus in abortion expels the decidua with considerable difficulty, but the ovum containing the fetus may slip out easily and be lost. A fetus two months old is about three-fourths of an inch in length. If a physician, nurse, or other person finds the ovum, no matter how small it is, they should open it at once with a scalpel or scissors and baptize the fetus conditionally, even if no sign of life is perceptible. If the fetus is unmistakably dead--a diagnosis not easily made--there is no use in attempting baptism; but always give the fetus the benefit of the doubt. In the first six or eight weeks the whole ovum is usually born developed in decidual tissue; sometimes the ovum will slip out of the decidua and be covered only with shaggy villi, suggestive of a chestnut burr.