The following table, prepared by Schrenck, gives an idea of the frequency of rupture of the perineum.
Causes.—Schrenck mentions as causes too slight inclination of the pel vis, delivery in the dorsal position, want of experience on the part of the physicians or students who preside over the delivery. There are other more important factors, such as non rotation of the head, rapid delivery with the forceps before the perineum has had time to dilate, or violent straining efforts on the part of the woman after the birth of the head. The slipping of the forceps is another cause, also the use of the cranioclast, the introduction of the hand, etc. There are, as Pajot says, some peri nea that are bound to tear, especially such as are thick, narrow, and in filtrated, or oedematous. The tear may involve the l'ourchette only, a por tion of the perineum, the edge of the sphincter, or the entire sphincter, and more or less of the recto-vaginal septum. As long as it does not ex tend entirely through the sphincter, it may be regarded as incomplete Finally, the sphincter and commissure may remain, while the centre of the perineum is perforated, sometimes sufficiently to allow of the passage of the child. Among 181 cases of ruptured perineum, Schrenck has noted 134 of the first degree, 41 of the second, and 1 of the third. Central rupture is rare; Morand (1869) collected 38 cases, in two of which for ceps were applied to the non-rotated head. These tears generally heal readily, though in some instances a permanent fistula may remain. Lacerations through the sphincter are followed by serious consequences, the partition between the rectum and vagina being removed, so that the two canals form a true cloaca; gas and feces are passed involuntarily and the woman's condition is deplorable; the support of the vaginal wall being destroyed, prolapse of the same, as well as cystocele and prolapsus uteri, result.
Treattnent.—This is prophylactic and curative.
1. Prophylaxis.—This consists in preventing the tear, or at least in limiting it to an incomplete rupture. The oldest method consists in sup porting the perineum; to that end the palm of the hand was applied to the perineum, with the thumb on one side of the vulva, and the fingers on the other; but this did net always prevent rupture, since, although the head was indirectly supported, its rapid expulsion was not hindered. Hence we have now abandoned this method, and endeavor to apply force directly to the head, retarding its progress so that the perineum may gradually become distended. Some authorities press directly upon the head, others indirectly, or through the anterior portion of the perineum. Depaul applies pressure to both the head and the anterior commissure, the former being thus kept at the edge of the vulvo-vaginal outlet, until the perineum is gradually distended, thus avoiding a complete laceration.
Hold, in addition to retarding the head, advises making an attempt to increase its flexion by pushing up the occiput; this he also does during the intervals of traction with the forceps. Olsliausen thinks that this manoeuvre is of slight value. Alt and Schroeder have advised placing the woman in the knee-elbow position, in order that gravity may assist in keeping the head under the pubic arch. The former writer states that in 100 women deliveredin this posture the frenum was intact in 50, and that only 25 had actual lacerations. Since it was almost impossible to make patients assume this position, the lateral was substituted for it. Olahausen supports the perineum with one hand, with the woman on her side, while with the four fingers of the other he supports and opposes the advance of the head. He does not use chloroform at this stage, because, in order to obtain complete relaxation of the abdominal muscles, it would be necessary to produce too profound anaesthesia; it is better, he thinks, to utilize the muscular contractions, rather than to eliminate them, in producing gradual distension of the perineum. He also recommends the introduction of two fingers into the rectum, so as to make pressure on the brow, while the thumb is pressed against the head at the anterior commissure; in this way too rapid expulsion can be prevented and a threatening tear be avoided, the head being slowly rolled out until it is entirely disengaged. Goodell describes a similar manoeuvre, but his ob ject is to act, not upon the head, but upon the ano•erineal border, by drawing the entire perineum forwards, and thus relieving the tension upon it. Hunt raises the objection, very properly, that we thus defeat our own object, because in thus drawing the perineum forwards, we in crease the chances of rupture; the perineum ought rather to be drawn backwards, so as to carry the vulvar cleft in the direction of the expulsive force, and thus to diminish the muscular resistance of the posterior half. It is better, when rupture is imminent, to perform episiotomy, or to incise the constrictor cunni. Simpson and Cohen have even advised gab-mu cous division of the muscle. -Olshausen does not believe that the use of the forceps prevents rupture, since in 244 cases in which they were ap plied in the Hallo Clinic, there were 76 lacerations, 36 being in primi pan3e, or one per cent., while in spontaneous delivery the average was only six per cent.