CHAPTER XVH ^ MISCARRIAGE Definition— Legally, miscarriage means the premature expulsion of the product of conception, an ovum or a foetus, from the uterus, at any period of pregnancy before the full term is reached. Medically, three distinct terms, viz. abortion, miscarriage and premature labour, are used to denote the expulsion of a foetus at different stages of gestation. Thus, the term abortion is used only when an ovum is expelled within tha^rstjh^^mogths of pregnancy, before "the placenta is formed. Miscarriage is~us^5wEen a foetus Is expelled from the fourth to the seventh month of gestation, before it is viable, while premature labour is the delivery of a viable child possibly capable of being reared, before it has become fully mature. CLASSIFICATION OF MISCARRIAGE Miscarriage may be classified as natural and artificial} the latter being sub-divided into justifiable and c7immaZT~~ NATURAL MISCARRIAGE It must be remembered that miscarriages are naturally common among pregnant women, the proportion being one miscarriage to every four or five full-term deliveries. Miscarriages are most frequent within the first four months of pregnancy owing to the slight attachment of the ovum to the uterine wall. Within the first few weeks the ovum being very minute is cast off without being recognized or miscarriage being suspected. Very many cases, in which the woman goes one or two weeks over her time, and then has what is supposed to be merely a more than usually profuse periodr are probably instances of such early miscarriages. Causes. — The causes of natural miscarriage are classified as those which are directly referable to the mother, and those which affect the foetus. A, Causes referable to the Mother. — 1. Poisons, circulating in the "blood, such as small-pox, plague, influenza, malaria, syphilisV streptococcal infection, lead, copper^ and mercury: Among These syphilis is one of the loost frequent causes of miscarriage, and is likely to act in successive pregnancies. It causes the death of the foetus. Streptococcal infection of a chronic nature is supposed to be the cause of cases of repeated abortion, where nb other cause can be detected. Curtis1 has isolated the streptococcus as the direct cause of abortion in several cases reported by him. He isolated the streptococci from the urine of a mother whose child was born dead, from the placenta, and also from the heart's Hood of the still-l>orn child. 2. Diseases affecting the circulation of the blood, such as anaemia due to excessive lactation or vomiting, jaundice, chronic Bright's disease, and heart and lung diseases. 3. Tbose aetjyiff through th** npgyons system, e.g, sudden shock, fear, gravidarum and reflex action from irritation of "the bfewifer, \'> ^ $uet as inflammations^ chronic displacements ancl ^sf 0M-peff!i§neal adhesions, and excessive sextial focal JPtetewt* aa$ IMhfeK? **& ^*& ®®d Tqo^ Ed B^ Vol. I, p, 970.