The rate of involution not only varies greatly with different women, but varies much after the different labors of the same woman.
Ordinarily at the end of the first week the fundus should lie midway between the navel and the pubes, and should shrink rapidly thereafter.
The necessity for watching the rate of involution is imperative for a number of reasons. If involution is slow, or stops, it may indicate fatigue of the muscle from multiparity or over-distention (twins, hydramnios, etc.) or it may follow a post partum hæmorrhage. Subinvolution may also indicate infection, the retention of clots, or pieces of placenta. It happens also when the woman gets up too soon or does not nurse her child and thereby delays the restoration of her waistline, as well as diminishes her resistance to disease.
The binder is objectionable to some doctors on the ground that it favors retroversion of the uterus during involution.
This would be a plausible theory when the uterus is high, if it were not that the vertebræ of the patient and the pelvic brim keeps the uterus from being pushed out of its place and after the uterus descends into the pelvis the gentle pressure of the binder evenly distributed over the abdomen can not affect it appreciably. Furthermore, the uterus in involution shows a persistent tendency toward anteflexion and anteversion.
The binder is merely a girdle put on just tight enough to hold in place the bandage that supports the perineal pads and to allow the patient more easily to grow accustomed to the sudden change in intraabdominal pressure which the delivery of the child creates. However, if the doctor objects to a binder, it may be left off with safety.
The Lochia.—When the placenta is delivered, the uterus normally closes down and all gross hæmorrhages cease; but for the next two weeks or possibly longer, a vaginal discharge continues. For the first few days it is hæmorrhagic in character and it is called lochia rubra, and consists mostly of fluid blood with occasional small clots. By the fourth day, usually it has become brown and thinner. It is now called lochia serosa. By the tenth day, it is yellowish-white, and is called lochia alba.
The lochia is the wastage from the shrinking uterus, and is made up of red blood corpuscles, epithelial cells, leucocytes, and pieces of broken-down deciduæ. The entire lining of the uterus is loosened, discharged and a new one formed during the puerperium. The lochia is regularly infected by bacteria in the vagina. If involution is slow, the lochial discharge may be prolonged.
The After-Pains.—The puerperium is not infrequently accompanied by painful contractions of the uterus called after-pains. These are more common in multiparas and serve a useful purpose in maintaining a definite contraction of the uterus.
If the pains are at all severe, they are a suggestive symptom of the retention of blood clots, a fragment of placenta, or of membrane. This, of course, will occur either in a primipara or multipara. In all cases the after-pains must be differentiated from gas and from the pains of pelvic inflammation.