Pelvic contraction is not infrequently the cause of difficult or prolonged labor. The deformity is most commonly due to rickets in childhood.

There are many forms of pelvic contraction, but in this country only two are at all common; the generally contracted, and the flat pelvis.

The generally contracted pelvis is, in the main, a well shaped pelvis, only its measurements are smaller than normal.

The flat pelvis is marked by a shortening of the anteroposterior diameter of the inlet. It looks as if it had been pressed together from before backward while in a soft condition.

These and other deformities will be recognized in advance of labor by the routine application of the pelvimeter.

The value of this instrument is so great, that no competent man does obstetrical work at the present time without using the pelvimeter as a routine.

The average diameters in normal pelves may be tabulated as follows:

Interspinous—between the anterior superior iliac spines—25 cm.

Intercristal—between the iliac crests—28 cm.

External conjugate—taken from the upper border of the symphysis to the depression below the last lumbar vertebra—20.5 cm. Take 9.5 cm. from this to get the true conjugate.

The circumference of the hips just below the iliac crests and above the trochanters—90 cm. It is taken with a tape line. These are the usual external measurements.

The internal measurements are made with the fingers.

The diagonal conjugate is the distance from the lower border of the symphysis to the promontory of the sacrum. It should measure 12.5 cm. The first and second fingers are passed into the vagina and pushed up until the tip of the second finger touches the promontory of the sacrum. The finger of the other hand marks the depth of the examining fingers just below the symphysis. The distance is measured when the finger is withdrawn, and 1.5 cm. is subtracted. The result is the true conjugate. These measurements carefully made and the deduction judicially estimated, give one a fairly approximate idea of size and shape of the pelvic inlet. The aim of nearly all the pelvic measurements is to get not only the size and shape of the inlet, but so far as possible, a working estimate of the anteroposterior diameter of the brim, which is the most important of all the diameters. In normal cases this should be 11 cm.

Thus, taking 9.5 cm. from the external conjugate (20.5 cm.) gives 11 cm.

Subtracting 1.5 cm. from the diagonal conjugate as obtained with the fingers as above described, (12.5 cm.) gives 11 cm. The subtraction is made to compensate for the thickness of the pubic bone and its inclination outwards.

A circumference of 90 cm. corresponds to an inlet of 11 cm. in its anteroposterior diameter, and every variation of 5 cm. in this circumference makes a difference of 1 cm. (either larger or smaller) in the anteroposterior diameter.

Thus, 95 cm. in circumference=12 cm. in the diameter; and 85 cm. in circumference=10 cm.

Complications increase in proportion to the degree of contraction in the pelvis.

The most frequent difficulties superinduced by the small pelvis are prolapse of the cord, malpresentation and malpositions of the head, prolonged labor, and a large increase in the number of assisted deliveries.

All the possibilities and probabilities in a given case will be carefully worked out before labor by the conscientious obstetrician, and CÆsarean section, induction of premature labor, pubiotomy, forceps, or version and extraction, will be done with a sure foreknowledge.

Prolapse of the cord complicates labor once in about two hundred cases. It is most likely to occur when the presenting part does not enter or does not entirely fill the opening, as in transverse or shoulder presentations, or vertex presentations with small inlets.

The mother is not endangered by this mishap, but the babe is lost in from 35 to 60 per cent of the cases.

The diagnosis is easily made when a loop of cord protrudes from cervix or vulva, and the pulsation will differentiate it from everything else.

If the cord does not pulsate, the family should be informed that the child is dead and the case may be allowed to terminate normally.

If it still pulsates, the woman should be placed in the knee-chest position for ten or fifteen minutes, then upon the side, opposite to that on which the cord has prolapsed, and back again as soon as possible to the knee-chest position. A chair may be used to produce a Trendelenburg position by placing it so that the edge of seat and top of back rest on the bed. Then the patient puts her legs over the lower rungs and lies with her back against the chair back and her head on the bed.

If the cervix is effaced and the os partly dilated, reposition may be attempted either with the finger or a male catheter.

The operation will, of course, succeed most easily if done in the knee-chest position, with gravity to aid.

If the cord can be pushed back, a Vorhees bag may be inserted to keep it from coming down again. This holds back the cord, dilates the canal and stimulates the pains.

When the bag comes out, version and extraction can and should be done at once.

In general, the following summary may be useful:

Causes.—

Contracted pelves.

Breech and transverse presentations.

Malposition of head, or face and forehead presentation.

Hydramnios.

Accident.

Low insertion of placenta.

Diagnosis.—

Before rupture of membranes careful examination will show pulsating cord in advance of head.

After rupture the cord may be felt in vagina.

Dangers.—

To mother:—None but those due to causative condition.

To child:—Compression of the cord and asphyxiation.

Contraction of exposed vessels of cord.

Patient may lie on cord.

Twenty-five per cent die as a rule under best conditions.

Fifty per cent when left to nature.

Treatment of Cephalic Presentation.—

Extraction of child or reposition of cord, depending upon the degree of dilatation.

If cervix is small, replace and fill cervix with Vorhees bag.

When cervix admits hand, either replace or do version and extraction.

With head engaged, reposition or version is not possible.

Child living:—Rapid delivery with forceps.

Child dead:—Craniotomy or leave to nature.

Prolapse of one or both hands may take place. If the head is engaged, no interference should be attempted. If not, replacement or version may be done.

The soft parts may also complicate the labor process.

No time need be spent here on the rarer forms of obstruction due to uterine or ovarian tumors.

Rigidity of the cervix, or os is not uncommon.

This may be due to a dense, almost cartilaginous consistence of that tissue, to premature rupture of the bag of waters, to weak, inefficient contractions in the first stage, or to a steel-spring-like contraction of the muscular fibers of the os.

In all cases the first stage of labor is greatly prolonged, but so long as the membranes are intact, the child is in no danger.

Two kinds of cases are met with, those in which the pains are violent, and those in which they are weak and shallow. In the first class, as soon as the condition is recognized, a dose of morphine sulphate, ? gr. and scopolamine hydrobromide 1/150 gr. should be given, hypodermically. The rigid ring relaxes under the influence of the narcotic, and labor proceeds rapidly and almost painlessly. Chloroform may be substituted if the morphine and scopolamine are not at hand. If the cervix is effaced and only the rigid ring of the os prevents the completion of the labor, or if the above methods fail, then the patient may be anÆsthetized and the rigidity overcome by the fingers. This is an emergency that should not be attempted until all else has failed and some danger arises that makes it necessary to hasten the delivery. (See Minor Operations, p. 211).

Where the constriction is due to unusual density of the cervix or to cicatricial tissue, it is sometimes necessary to make incisions under aseptic precautions so that the rigid ring may expand.

Weak and inefficient contractions can sometimes be stimulated satisfactorily by the introduction of a Vorhees bag.

Rigidity of the pelvic floor may be due to inadequate elasticity of the tissues as in old primiparas or in young women who have ridden horseback for many years in the cross-saddle position.

The head may come down to the pelvic floor but will not advance further. If the tissues of the vulva do not, or can not yield sufficiently after appropriate time has been allowed, episiotomy may be done. (See Minor Operations, p. 211.)

The uterus itself may functionate abnormally.

Precipitate labor is an over rapid advance of the child wherein the stages of labor are merged into one another and the child expelled in two or three pains.

It may be due to unusual capacity of the pelvis, or to strong contractions which the patient is not aware of, or both. These cases predispose to post partum hÆmorrhage and to serious lacerations of cervix and perineum.

The child is usually delivered in an undesirable place, such as a toilet basin or a street car, and perishes from the fall, from cold, from umbilical hÆmorrhage, or lack of facilities for revival.

The nurse who is watching a case is responsible for the prevention of a precipitate. If the event impends, the woman must be placed upon her side with legs straight, and she should be instructed to cry out with every pain. Chloroform may be given and the head forcibly held back.

Uterine Inertia.—A sluggish state of the uterus may characterize the labor and the contractions will be slow, shallow and inefficient. The intervals may be prolonged, although the patient complains bitterly of pain.

The condition is seen most frequently in multiparas and is due to defective innervation of the uterus or to imperfect reflexes, and in primiparas also it may be due to the newness of the function that is suddenly called into play, or to contracted pelvis. Many times the trouble results from overfatigue and want of sleep. If this is the case, the remedy may be found in the administration of morphine sulphate ? gr. and scopolamine 1/150 gr. The pains are diminished or abrogated while the contractions continue. The scopolamine may be repeated if necessary. Under proper indications and conditions this treatment is harmless, both to mother and child, but requires supervision on the part of the nurse or physician.

If the patient is not overly fatigued, the introduction of a Vorhees bag, as described under the head of Induction of Labor (p. 208) will dynamically increase the strength and frequency of the contractions, mechanically aid the effacement of the cervix and the dilatation of the os, and shorten the first stage anywhere from six to twelve hours.

As soon as the os is dilated, pituitrin may be given under due precautions, as hereafter indicated. Pituitrin has but little influence on the nonfunctionating organ, but acts well on a uterus which is definitely contracting. It should not be given during the first stage, since when the uterus contracts, there must be an adequate opening for the advance of the child. Five to seven minims is the usual dose, injected into the deltoid muscle. The injection may be repeated in an hour, if required, since the effects, which begin about five minutes after the injections, will pass off in fifty-five minutes.

By the use of pituitin many operative procedures are altered or avoided. A high forceps case may be converted into a case for the low instruments, and the latter in many instances avoided altogether.

The use of pituitin may be briefly summarized as follows:

Indications.—

1. Inertia uteri or weak, shallow pains in second stage.

2. Multiparity.

3. Post partum hÆmorrhage.

4. To avoid use of forceps or to reduce a high forceps case to a low one.

5. CÆsarean section.

If the patient is a multipara, sterile linen should be on and attendants ready for the delivery before an injection is given.

Conditions.—

1. Cervix effaced.

2. Os admits three fingers. (Better if membranes have ruptured.)

3. Head should be engaged.

4. No mechanical obstacle to delivery such as tumors or markedly contracted pelvis, etc.

Dangers of Long Labors.—

Compression of cord.

Infection—peritonitis.

Necrosis of skin over skull.

Necrosis of cranium.

Fracture of skull.

Death of child.

Maternal exhaustion and prolonged convalescence.

Premature rupture of the membranes not infrequently occurs from over-distention, when twins or hydramnios is present, or at any stage of the pregnancy when the membranes are weak. The liquor amnii flows off, not all at once, but after the first gush by intermittent discharges, depending on the painless uterine contractions and the accuracy with which the head fits the pelvis. Labor usually comes on in from twelve to forty-eight hours, but it may be postponed for a month.

The labor is sometimes more painful and prolonged on account of the absence of the fluid wedge and the generous lubrication of the channel which is supplied by the liquor amnii.

The danger of infection of the amniotic cavity with consequent death of the child is always to be apprehended after the escape of the liquor amnii. Also the foetal parts may prolapse and complicate the labor; or if the cord comes down, the child may be imperiled by its compression.

If near term, the rupture of the membranes is not of great importance though the case must be watched attentively. Daily observation must be made of the foetal heart tones, the amount of liquor amnii flowing away, and the presence or absence of infection. If labor does not determine in a few days or if the heart tones rise above 160 or go below 120, labor must be inaugurated. (See Induction of Labor, p. 208.)

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.