Prepared by professor S.N.Heryak
Ternopol medical state univercity
by I.Y. Gorbachevsky
Cesarean delivery is defined as the birth of a fetus through incisions in the abdominal wall (laparotomy) and the uterine wall (hysterotomy). This definition does not include removal of the fetus from the abdominal cavity in the case of rupture of the uterus or in the case of an abdominal pregnancy.
Cesarean section is defined as delivery of an infant, alive or dead, through an abdominal uterine incision. Cesarean section is the most common operation performed in the United States; approximately one million cesarean deliveries were performed in this country in 1991, accounting for one-quarter of all live births (National Hospital Discharge Survey, ).
Perhaps no other surgical or medical procedure has generated as much controversy as cesarean delivery, and the operation continues to be debated both in the scientific and lay press and media. Such controversy arises from several factors. The performance of cesarean section to many women involves disruption of the natural birth process and invokes a host of psychologic and emotional issues quite apart from the medical goal of a healthy mother and infant. Further, both for the individual and society, cesarean section has enormous cost implications.
Maternal: Maternal diseases, Eclampsia, Cardiac disease, Previous uterine surgery (cesarean section, previous uterine rupture, myomectomy), Obstruction to the birth canal (cervical cancer, previous cervical or vaginal surgery, ovarian tumors), Abnormal uterine action.
Fetal: Fetal distress, Cord prolapse, Fetal malpresentations (breech, transverse lie, brow), Cephalopelvic disproportion, Placenta previa, Abruptio placentae
The four most frequent indications for cesarean delivery are (1) repeat cesarean, (2) dystocia or failure to progress in labor, (3) breech presentation, and (4) those performed out of concern for fetal well-being. Repeat cesarean deliveries and those performed for labor dystocia together account for approximately half of all such operations, both in the United States and other western industrialized countries (Notzon and associates, 1994; Rosen and colleagues, 1991; Soliman and Burrows, 1993).
As emphasized by Leveno and associates (1985, 1989), population differences preclude definitive conclusions based upon direct comparisons of these data. Nevertheless, several points are worth emphasizing. First, the rates of cesarean delivery practices for breech, fetal distress, and “other” are similar across all populations examined. Second, the rates of cesarean deliveries for previous cesareans and labor dystocias differ markedly between the United States and European industrialized countries, with those of Canada falling in between. Thus, any reductions in the rate in the United States will most likely come about by more selective diagnoses of labor dystocia and a wider acceptance of vaginal birth after a previous cesarean. Finally, the finding of a significantly lower overall cesarean rate for Norway than the United States, despite virtual universal repeat cesarean delivery in that country (94 percent), confirms the observations of Paul and Miller (1995) that unless the primary cesarean rate in the United States is reduced, an important reduction in overall cesarean rate is unlikely.
Coincidental with the increase in cesarean deliveries in the United States has been a dramatic decline in the perinatal mortality rate. Although this may appear to be cause and effect, a similar trend in perinatal mortality has been seen outside the United States with little or no change in cesarean rate . Such considerations have led many both within and outside the medical community to question whether a quarter of all infants in the United States would have demonstrated worse outcome had they been born vaginally.
Although it is not possible to catalog comprehensively all appropriate indications for cesarean delivery, over 85 percent are performed because of (1) prior cesareans, (2) labor dystocia, (3) fetal distress, or (4) breech presentation. We will now turn to these indications.
Prior Cesarean Delivery
For many years, the scarred uterus was felt to contraindicate labor out of fear of uterine rupture. Indeed, with a classical uterine incision, about 12 percent of women will suffer rupture if given a trial of labor. One third of women with a classical cesarean who suffer uterine rupture do so prior to labor (Halperin and associates, 1988; Rosen and co-workers, 1991). In the past 15 years, however, there has been ample proof of the relative safety for a trial of labor in most women after a low-transverse cesarean. Efforts to encourage vaginal birth after cesarean (VBAC) appear to be the most productive approach to lowering the cesarean rate (DeMuylder, 1990; Hage, 1988; Porreco, 1990; Pridijian, 1991; Sanchez-Ramos, 1990; and their associates). Presently, about half of women eligible for a trial of labor choose this option, with a 60 to 80 percent success rate (American College of Obstetricians and Gynecologists, 1995b). In considering vaginal birth after cesarean, several factors bear special consideration.
ELECTIVE STERILIZATION. Desire for permanent sterilization in a woman with a prior cesarean is not an indication for a repeat operation because the morbidity of vaginal birth and postpartum tubal ligation is considerably less than that of a repeat cesarean.
OXYTOCIN AND EPIDURAL ANALGESIA. A critical analysis of the available data demonstrates no evidence that the use of oxytocin should be modified in a woman laboring with a prior low-transverse incision (American College of Obstetricians and Gynecologists, 1995b; Rosen and associates, 1991). Results from one case-control study were consistent with an increased risk of uterine rupture with inappropriate use of oxytocin (Leung and co-workers 1993).
The use of epidural analgesia has been debated in the past out of fear that such a technique might mask the pain of uterine rupture. However, less than 10 percent of women with scar separation experience pain and bleeding, and fetal heart rate decelerations are the most likely sign of such an event (Flamm and associates, 1990). Several studies attest to the safety of properly conducted epidural analgesia (Farmer and colleagues, 1991; Flamm and associates, 1994).
EXAMINING THE SCAR. Although some obstetricians routinely document the integrity of the old scar by palpation following successful vaginal delivery, such uterine exploration is felt to be unnecessary by others. Currently it is not known what effect documentation of an asymptomatic scar has on subsequent reproduction or route of delivery. There is general agreement, however, that surgical correction of a scar dehiscence is necessary only if significant bleeding is encountered. Asymptomatic nonbleeding separations do not generally require exploratory laparotomy and repair.
Elective Repeat Cesarean Delivery
ELECTIVE REPEAT CESAREAN DELIVERY. If repeat cesarean is elected, it is essential that fetal maturity be achieved prior to elective delivery. The American College of Obstetricians and Gynecologists (1991) has established guidelines for timing an elective operation. According to these criteria, elective delivery may be considered at or beyond 39 weeks if at least one of the criteria outlined in Table 22–4 are met. In all other instances, fetal pulmonary maturity must be documented by amnionic fluid analysis before elective repeat cesarean is undertaken . Alternately, the onset of spontaneous labor is awaited.
This is the most frequent indication for cesarean delivery in the United States. An analysis of labor dystocia as a contributing factor to the cesarean rate is difficult, however, because of the heterogeneity inherent in the condition . According to Notzon and associates (1994), 15 different ICD-9 codes exist describing cesarean delivery for labor dystocia! Descriptive terms vary from more precise definitions promulgated by Friedman (1978)—secondary arrest of dilatation, arrest of descent—to more ambiguous and commonly used terms such as cephalopelvic disproportion and failure to progress. It is meaningless to classify cesarean delivery performed after 8 hours of contractions at 3 cm dilatation for “failure to progress” in the same category as a woman undergoing cesarean delivery for arrest of descent after 3 hours of pushing with uterine contractions demonstrating 300 Montevideo units. Not surprisingly, efforts to reduce cesareans in this category have been less successful than for repeat cesarean deliveries .
The 1970s witnessed the development of electronic fetal heart rate monitoring as well as elegant descriptions of various fetal heart rate patterns and their association with fetal oxygenation and acid–base status. Such observations raised hopes that widespread recognition of various subtle parameters of “uteroplacental insufficiency” and timely cesarean delivery would allow the obstetrician to avoid childhood neurological abnormalities including cerebral palsy. Despite relatively poor specificity in the prediction of an abnormal newborn, a lack of scientific foundation for defining “normal” and “abnormal” newborn acid–base status, and widespread disagreement among experts regarding fetal heart rate interpretation, prompt recognition of various subtle patterns was often seen as the key to diagnosing “fetal distress” and preventing neurological damage .
Despite the paucity of data, an entire industry developed around these techniques, and many proponents suggested that properly conducted randomized trials would be unethical. Subsequently, it has become well established that management based upon electronic monitoring neither reduces the risk of cerebral palsy, nor improves any measurable indices of newborn outcome compared with intermittent heart rate auscultation (American College of Obstetricians and Gynecologists, 1992, 1995b; Freeman, 1992; Nelson and co-workers, 1996). Scheller and Nelson, in a report from the National Institutes of Health (1994), and Lien and associates (1995) presented data specifically refuting any association between cesarean delivery and either cerebral palsy or seizures.
The American College of Obstetricians and Gynecologists (1992) recommends that facilities giving obstetrical care have the capability of initiating a cesarean delivery within 30 minutes of the decision for operation. This recommendation addresses facilities and does not govern clinical decision making. Misinterpretations of this guideline are common. There is no nationally recognized standard of care that codifies an acceptable time interval for performance of cesarean delivery. In most instances, operative delivery is not necessary within this 30-minute time frame. In cases of cesarean for indications such as labor arrest, a timely cesarean often will involve an interval considerably in excess of 30 minutes. On the other hand, when faced with an acute, catastrophic deterioration in fetal condition, cesarean may be indicated as rapidly as possible, and purposeful delays of any time period would be inappropriate.
Fetuses presenting as a breech are at increased risk of cord prolapse and head entrapment if delivered vaginally compared with those presenting as a vertex. Nevertheless, prospective controlled trials are suggestive that with proper selection, certain fetuses may deliver vaginally in breech presentations with minimal risk. It should be emphasized, however, that in many of these studies, increased death or permanent neurological damage was repeated in the groups delivered vaginally, yet small numbers precluded statistical significance. A recent meta-analysis of available studies is suggestive of a significant fourfold increase in both perinatal mortality and traumatic morbidity for planned vaginal versus planned cesarean birth (Cheng and colleagues, 1993). When weighed against known maternal risks of cesareans, such small fetal risks may be acceptable; with appropriate informed consent, carefully selected fetuses meeting established criteria may undergo a trial of labor (American College of Obstetricians and Gynecologists, 1986). Concern for fetal injury, however, as well as the infrequency with which a breech fetus meets criteria for a trial of labor, make it unlikely that significant reductions in the cesarean birth rate will come from a more liberal approach to vaginal breech delivery.
The fetus may change positions between the time of preoperative assessment and delivery. This is especially common in premature infants, multiple gestations, and pregnancies complicated by hydramnios. It is important to quickly assess the lie after the uterus has been opened, especially in nonvertex presentations. There should be no hesitation in converting a low-transverse incision into a "J" or hockey stick type incision if there is any question of the ability of the operator to effect atraumatic delivery through the initial incision line. "T"-shaped incisions are the least preferred as healing may be impaired; but if needed they should be employed.
Methods to Decrease Cesarean Delivery Rates
Several investigators have documented the feasibility of achieving significant reductions in institutional cesarean rates without increased perinatal morbidity or mortality (DeMott, 1990; DeMuylder, 1990; Porreco, 1990; Pridijian, 1991; Sanchez-Ramos, 1990; and their co-workers). Programs aimed at reducing unnecessary cesarean deliveries are generally focused upon educational efforts and peer review, encouraging a trial of labor after prior transverse cesareans, and restricting cesareans for labor dystocia to women who meet strictly defined criteria. Such efforts, along with increased understanding of the proper use of electronic fetal heart rate monitoring, should further reduce the frequency of cesarean delivery.
Maternal Mortality and Morbidity
Maternal mortality has decreased dramatically in the past 50 years, from 650 per 100,000 births in 1940 to 14.1 per 100,000 live births in 1988 (Rochat and colleagues, 1988). Traditionally, the major sources of operative mortality in women undergoing cesarean delivery were anesthetic accidents, hemorrhage, and infection. However, with improved anesthetic techniques and training, availability of antimicrobial agents, and modern blood-banking techniques, deaths from aspiration, infection, and hemorrhage are much less common. Indeed, thromboembolic events are the major cause of direct maternal death in the United States and account for a quarter of such deaths.
In the United States, maternal death associated with cesarean delivery is rare. In 1980, Frigoletto and colleagues reported a series of 10,000 consecutive cesareans with no maternal deaths. In 1988, Sachs and associates observed only seven deaths as a direct result of cesarean births in over 121,000 cesareans performed between 1976 and 1984. In 1990, Lilford and co-workers, while documenting a 7-fold relative risk for maternal mortality associated with cesarean delivery, observed that most deaths were associated with complicated nonelective procedures. Indeed, the relative risk of death for elective cesareans under epidural analgesia was actually lower than that associated with all vaginal births.
Although maternal death is an infrequent sequel of cesarean birth, morbidity is increased dramatically compared with vaginal delivery. Principle sources of morbidity are endomyometritis, hemorrhage, urinary tract infection, and nonfatal thromboembolic events. As discussed in Chapter 50 , morbidity associated with cesarean delivery is increased dramatically in obese women (Isaacs and associates, 1994; Perlow and Morgan, 1994). These factors, as well as the increased recovery time associated with cesareans, result in a twofold increase in costs for cesarean compared with a vaginal delivery (Source: Book of Health Insurance Data, 1993).
Although cesarean delivery is sometimes performed in cases of malpresentation or, rarely, with known excessive fetal size in an effort to avoid birth trauma, it is incorrect to assume that a cesarean delivery provides a guarantee against such injury. Numerous reports attest to the occurrence of Erb palsy, skull fractures, and fractures of other long bones in infants delivered by cesarean (Kaplan and colleagues, 1987; Skajaa and associates, 1987; Vasa and Kim, 1990). DeMott and co-workers (1990) demonstrated a relative risk of 4.5 for transient tachypnea of the newborn in term infants delivered by cesarean compared with vaginal birth.
Scissors are inserted between the serosa and myometrium of the lower uterine segment and are pushed laterally from the midline, while partially opening the blades intermittently, to separate a 2-cm-wide strip of serosa, which is then incised. As the lateral margin on each side is approached, the scissors are aimed somewhat more cephalad .
The lower flap of peritoneum is elevated and the bladder is gently separated by blunt or sharp dissection from the underlying myometrium .
In general, the separation of bladder should not exceed 5 cm in depth and usually less. It is possible, especially with an effaced, dilated cervix, to dissect downward so deeply as inadvertently to expose and then enter the underlying vagina rather than the lower uterine segment.
The uterus is opened through the lower uterine segment about 1 cm below the upper margin of the peritoneal reflection. The uterine incision can be made by a variety of techniques. Each is initiated by incising with a scalpel the exposed lower uterine segment transversely for 2 cm or so halfway between the lateral margins. This must be done carefully so as to cut completely through the uterine wall but not deeply enough to wound the underlying fetus .
Careful blunt entry using hemostats to split the muscle may be helpful. Once the uterus is opened, the incision can be extended by cutting laterally and then slightly upward with bandage scissors; or when the lower uterine segment is thin, the entry incision can be extended by simply spreading the incision, using lateral and upward pressure applied with each index finger (Fig.).
Rodriguez and associates (1994) demonstrated that blunt and sharp extensions of the initial uterine incision are equivalent in terms of safely and postoperative complications. It is very important to make the uterine incision large enough to allow delivery of the head and trunk of the fetus without either tearing into or having to cut into the uterine arteries and veins that course through the lateral margins of the uterus. If the placenta is encountered in the line of incision, it must either be detached or incised. When the placenta is incised, fetal hemorrhage may be severe; thus, the cord should be clamped as soon as possible in such cases.
Delivery of the Infant
If the vertex is presenting, a hand is slipped into the uterine cavity between the symphysis and fetal head, and the head is elevated gently with the fingers and palm through the incision aided by modest transabdominal fundal pressure .
After a long labor with cephalopelvic disproportion, the fetal head may be rather tightly wedged in the birth canal. Upward pressure exerted through the vagina by an assistant will help to dislodge the head and allow its delivery above the symphysis. To minimize aspiration by the fetus of amnionic fluid and its contents, the exposed nares and mouth are aspirated with a bulb syringe before the thorax is delivered. The shoulders then are delivered using gentle traction plus fundal pressure. The rest of the body readily follows.
As soon as the shoulders are delivered ,
an intravenous infusion containing about 20 U of oxytocin per liter is allowed to flow at a brisk rate of 10 mL/min until the uterus contracts satisfactorily, after which the rate can be reduced. The cord is clamped with the infant held at the level of the abdominal wall, and the infant is given to the member of the team who will conduct resuscitative efforts as they are needed.
If the fetus is not presenting as a vertex, or if there are multiple fetuses or a very immature fetus of a woman who has had no labor, a vertical incision through the lower segment may, at times, prove to be advantageous. The fetal legs must be carefully distinguished from the arms to avoid premature extraction of an arm and a difficult delivery of the rest of the fetus.
The uterine incision is observed for any vigorously bleeding sites. These should be promptly clamped with Pennington or ring forceps, or similar instruments. The placenta should be removed promptly manually, unless it is separating spontaneously .
Fundal massage, begun as soon as the fetus is delivered, reduces bleeding and hastens delivery of the placenta.
Repair of the Uterus
After delivery of the placenta, the uterus may be lifted through the incision onto the draped abdominal wall and the fundus covered with a moistened laparotomy pack. Although some clinicians prefer to avoid this latter step, uterine exteriorization often has advantages that outweigh any disadvantages. The relaxing uterus can be recognized quickly and massage applied. The incision and bleeding points are visualized more easily and repaired, especially if there have been extensions laterally. Adnexal exposure is superior and thus tubal sterilization is easier. The principal disadvantage is from discomfort and vomiting caused by traction in the woman given spinal or epidural analgesia. Neither febrile morbidity nor blood loss appears to be increased in women undergoing uterine exteriorization prior to repair (Magann and associates, 1993a).
Immediately after delivery and inspection of the placenta, the uterine cavity is inspected and is wiped out with a gauze pack to remove avulsed membranes, vernix, clots, or other debris. The upper and lower cut edges and each angle of the uterine incision are examined carefully for bleeding vessels. The lower margin of an incision made through a thinned-out lower uterine segment may be so thin as to be inadvertently ignored. At the same time, the posterior wall of the lower uterine segment may occasionally buckle anteriorly in such a way as to suggest that it is the lower margin of the incision. The uterine incision is closed with one or two layers of continuous 0 or #1 absorbable suture. Traditionally, chromic suture was used, but some prefer synthetic nonabsorbable sutures. Zuidema and colleagues (1996) reviewed subsequent outcomes in 537 women in whom 237 had uterine chromic closure and 302 had closure with vicryl. Subsequent scar separation was increased almost fourfold in the vicryl group (4.6 versus 1.2 percent). Individually clamped large vessels are best ligated with a suture ligature. Concern has been expressed by some that sutures through the decidua may lead to endometriosis in the scar, but this is a rare complication. The initial suture is placed just beyond one angle of the incision. A running-lock suture is then carried out, with each suture penetrating the full thickness of the myometrium .
It is important to select carefully the site of each stitch and not to withdraw the needle once it penetrates the myometrium. This minimizes the perforation of unligated vessels and subsequent bleeding. The running-lock suture is continued just beyond the opposite incision angle.
Especially when the lower segment is thin, satisfactory approximation of the cut edges usually can be obtained with one layer of suture. If approximation is not satisfactory after a single-layer continuous closure or if bleeding sites persist, either another layer of sutures may be placed so as to achieve approximation and hemostasis, or individual bleeding sites can be secured with figure-of-eight or mattress sutures. Hauth and colleagues (1992) randomized 761 women with a transverse uterine incision to closure with either one or two layers of #1 chromic suture. The single-closure technique required significantly less operating time and fewer hemostatic sutures. There were no differences in postoperative complications between the two groups. In a follow-up study of 164 of those same women, Chapman and co-workers (1996) reported similar outcomes in the one- versus two-layer closure groups.
After hemostasis is obtained from uterine closure, serosal edges overlying the uterus and bladder in the past have been approximated with a continuous 2-0 chromic catgut suture (Fig. ).
Hull and Varner (1991), however, demonstrated reduced need for postoperative analgesia and a quicker return of bowel function when both visceral and parietal peritoneum were left open. Similar results were obtained by Pietrantoni and associates (1991). Such a practice does not increase adhesion formation (Tulandi and co-workers, 1988).
If tubal sterilization is to be performed, it is now done. A partial midsegment salpingectomy, is associated with a low failure rate.
All packs are removed, and the gutters and cul-de-sac are emptied of blood and amnionic fluid by gentle suction. If general anesthesia is used, the upper abdominal organs may be palpated systematically. With conduction analgesia, however, this may produce considerable discomfort. After the sponge and instrument counts are found to be correct, the abdominal incision is closed .
As each layer is closed, bleeding sites are located, clamped, and ligated. The rectus muscles are allowed to fall into place, and the subfascial space is meticulously checked for hemostasis. The overlying rectus fascia is closed either with interrupted 0 nonabsorbable sutures that are placed well lateral to the cut fascial edges and no more than 1 cm apart, or by continuous, nonlocking suture of a long-lasting absorbable or permanent type.
The subcutaneous tissue usually need not be closed separately if it is 2 cm or less in thickness, and the skin is closed with vertical mattress sutures of 3-0 or 4-0 silk or equivalent suture or skin clips. If there is more adipose tissue than this, or if clips or subcuticular closure are to be used, a few interrupted 3-0 plain catgut sutures will obliterate dead space and reduce tension on the skin edges. In a randomized prospective study of more than 1400 women undergoing cesarean delivery, Bohman and colleagues (1992) reported a significantly decreased frequency of superficial wound disruption when the subcutaneous layer was approximated, a finding confirmed in a similar study by Naumann and co-workers
Obstetrical forceps are designed for extraction of the fetus.
General Design. Forceps vary considerably in size and shape, but basically consist of two crossing branches. Each branch is maneuvered into appropriate relationship with the fetal head and then articulated. Each branch has four components: the blade, shank, lock, and handle. Each blade has two curves, the cephalic and pelvic. The cephalic curve conforms to the shape of the fetal head, and the pelvic curve with that of the birth canal. Some varieties are fenestrated rather than solid to permit a more firm hold on the fetal head.
The cephalic curve (Fig. ) should be large enough to grasp the fetal head firmly without compression.
The pelvic curve corresponds more or less to the axis of the birth canal, but varies considerably among different instruments. The blades are connected to the handles by the shanks, which give the requisite length to the instrument. The shanks are either parallel as in Simpson forceps or crossing as in Tucker–McLane forceps.
The kind of articulation, or forceps lock, varies among different instruments. The common method of articulation consists of a socket located on the shank at the junction with the handle, into which fits a socket similarly located on the opposite shank .
This form of articulation is commonly referred to as the English lock. A sliding lock is used in some forceps, such as Kielland forceps . The sliding lock allows the shanks to move forward and backward independently.
Function and Choice of the Forceps
The forceps may be used as a tractor, rotator, or both. Its most important function is traction, although particularly in transverse and posterior positions of the occiput, forceps may be invaluable for rotation. Any properly shaped instrument will give satisfactory results, provided it is used intelligently. In general, Simpson forceps are used to deliver the fetus with a molded head, as is common in nulliparous women. The Tucker–McLane instrument is often used for the fetus with a rounded head, which more characteristically is seen in multiparas. In most situations, however, either instrument is appropriate. In some circumstances, more specialized forceps such as the Kielland instrument may be preferable, such as in some cases of deep transverse arrest with the fetal head in the transverse position well down in the pelvis with the occiput below the spines. If there is no apparent cephalopelvic disproportion and uterine contractions are inadequate, transverse arrest may sometimes be overcome with oxytocin stimulation, with resulting descent of the head to the perineum and spontaneous anterior rotation.
Forces Exerted by the Forceps
From experiments conducted on women in labor more than a century ago, Joulin (1867) estimated that a pull in excess of 60 kg might damage the fetal skull. These crude studies and subsequent ones have furnished only a gross approximation, for the force produced by the forceps on the fetal skull is a complex function of pull and compression by the forceps and friction produced by the maternal tissues.
Indications for Use of Forceps
The termination of labor by forceps, provided it can be accomplished safely, is indicated in any condition threatening the mother or fetus that is likely to be relieved by delivery. Maternal indications include heart disease, pulmonary injury or compromise, intrapartum infection, certain neurological conditions, exhaustion, or prolonged second-stage labor. The latter is defined by the American College of Obstetricians and Gynecologists (1988) as more than 3 hours with and more than 2 hours without regional analgesia in the nulliparous woman. In the parous woman, it is defined as more than 2 hours with and more than 1 hour without regional analgesia. Using the 1988 classification of forceps delivery, midforceps rarely are indicated for labor termination specifically for maternal reasons. Thus, shortening of second-stage labor for maternal reasons should generally be accomplished with outlet or low-forceps.
Fetal indications for operative vaginal delivery with either forceps or vacuum include prolapse of the umbilical cord, premature separation of the placenta, and a nonreassuring fetal heart rate pattern. Although “fetal distress” or “fetal jeopardy” are terms commonly used to define an indication for termination of labor, both terms are nonspecific and somewhat vague . In the case of a nonreassuring fetal heart rate pattern, which may or may not be associated with fetal distress or jeopardy, it is prudent to describe the fetal heart rate pattern and the station of the planned forceps application in a precisely written note.
Maternal indications include disease states that impair the ability to push or conditions that may be worsened by prolonged voluntary expulsive effort. Examples of the former include neurologic disorders associated with weakness and certain pulmonary diseases; maternal cardiac disease is the classic example of the latter. Collectively, these diseases are uncommon. More often forceps delivery is indicated by maternal fatigue or by a dense regional block that inhibits motor fibers. The latter was common when saddle block anesthesia was used for vaginal delivery, but a properly dosed epidural block should not interfere with muscular control and expulsive efforts to the same degree. Other anesthetic considerations are discussed in the section that follows.
Fetal indications for forceps delivery include non-reassuring fetal heart rate patterns. The degree of heart rate abnormality justifying or necessitating operative intervention is not well quantified whether it is diagnosed in the first or the second stage of labor. In the first stage, provided that the pattern cannot be resolved by intrauterine resuscitative measures, cesarean section is the only management option. In the second stage of labor, the obstetrician must carefully evaluate the clinical situation to determine whether abdominal or operative vaginal delivery will produce the best maternal and perinatal outcome. Forceps delivery may be more expedient than assembling an operating team for cesarean section. Conversely, a traumatic instrumental delivery from the midpelvic cavity may be avoided by judicious selection of cesarean delivery. It is well established that even the uncomplicated second stage of labor is associated with progressive fetal acidosis; safe shortening of this stage may be desirable. These decisions require judgment, skill, and individualization on the part of the operator.