=Rupture of the uterus= is the most serious accident that occurs in labor. It happens about once in three thousand confinements. The tear is usually in the lower part of the uterus and follows a prolonged period of labor, where the child is in a transverse presentation, and, therefore, impossible to deliver, or the pelvis is too small or the child too large. It may also follow ill-advised or unskillful efforts to change the presentation by the introduction of the hand into the uterus. Occasionally rupture is produced by external violence, such as blows or kicks upon the abdomen. It is imperative to be able to recognize the symptoms when rupture impends or actually occurs. _Signs of Threatened Rupture of Uterus._— 1. High position of the contracting ring—especially its obliquity. The contracting ring is a ridge-like formation that may be found running across the anterior and lower portion of the uterus. 2. High position of fundus. 3. Tension of round ligaments. 4. Rotation of uterus about its long axis. 5. Tenderness to pressure of lower uterine segment. 6. Contractions persistent with no pain-free interval. _Signs of Actual Rupture of Uterus._— 1. Hæmorrhage is one of the earliest and most significant signs, and may be either external or internal. 2. Cessation of uterine contractions either abruptly or gradually. 3. Extreme pain felt by patient. 4. Recession of presenting part. The patient gives a sharp cry and has the feeling that something has given way. Signs of shock rapidly supervene. A predisposition to rupture may be present from the scars of a Cæsarean section, uterine tumors, and degeneration of the muscle. _The treatment_ depends upon the degree of the injury, and if investigation shows that the uterus has opened into the abdominal cavity, immediate laparotomy is done. In other cases, the morcellation and removal of the child by the natural passage may permit the use of a uterine pack and avert the necessity for an abdominal operation. The child is usually dead and need not be considered. CHAPTER XV COMPLICATIONS IN LABOR (Cont’d) =Vomiting= in labor frequently occurs near the end of the first stage. It is due to the sympathetic excitement of the nerves of the stomach as the last fibers of the os uteri give way. It requires no treatment. Hyperemesis in labor is very rare, but when it does occur, the delivery should be expedited. =Hæmorrhages= may occur either before, during, or after labor. Hæmorrhage is always serious. Hæmorrhage before labor arises either from a premature detachment of a normally implanted placenta or from placenta prævia. The first is sometimes called “accidental hæmorrhage” to distinguish it from the latter, or “unavoidable hæmorrhage.”