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Operative Obstetrics

Forceps Delivery

The frequency of forceps delivery has declined significantly as the cesarean delivery rate escalated in the last two decades. Fear of fetal injury and subsequent litigation have been at least partially responsible for this trend. Also responsible were inadequate definitions that grouped relatively easy deliveries, with the fetal head at or near the pelvic floor, with higher, more difficult deliveries that included rotation of more than 90 degrees. Forceps deliveries are categorized according to station of the fetal head and degree of rotation required. The pelvis is subdivided by using centimeters from the ischial spines.

Forceps can be used to benefit the mother, fetus, or both. Maternal cardiac or neurologic conditions may prevent or contraindicate pushing; more often, maternal fatigue or an improperly dosed epidural may impede expulsive efforts. Nonreassuring FHR patterns may mandate delivery. Forceps delivery should be considered when a nulliparous woman has experienced arrested descent for 2 hours (3 hours with epidural anesthesia) and when a multiparous woman has had arrested descent for 1 hour (2 hours with an epidural anesthesia) vaginal birth after cesarean section.

The patient should be comfortably positioned in the dorsal lithotomy position with an empty bladder. Pudendal anesthesia is adequate for outlet procedures, whereas higher forceps require regional or general anesthesia. Before application, the operator confirms full dilatation and rupture of membranes. Clinical pelvimetry should rule out obvious cephalopelvic disproportion. Accurate assessment of fetal head position.

Although safe operative vaginal delivery is preferable to cesarean delivery, new data have tempered the enthusiasm for forceps operations. Forceps deliveries with greater than 45 degrees of rotation.

Classification of Forceps Deliveries According to Station and Rotation

Type of Procedure

Classification

Outlet forceps

1 ) Scalp visible at introitus without labial separation

2) Fetal skull has reached the pelvic floor

3) Sagittal suture is in anteroposterior diameter or right or left occiput anterior or posterior position

4) Fetal head is at or on perineum

5) Rotation does not exceed 45 degrees

Low forceps

Leading point of fetal skull is at station >+2 cm and not on the pelvic floor

a. Rotation <45 degrees (left or right occiput anterior to occiput anterior or left or right occiput posterior to occiput posterior

b. Rotation >45 degrees

Mid forceps

Station above +2 cm but head engaged

High forceps

Not included in classification

 

Vacuum Extraction

The definitions, indications, and prerequisites for vacuum extraction of the fetus are the same as for forceps deliveries. Contraindications include face or breech presentation and cephalopelvic disproportion; relative contraindications include prematurity, macrosomia, fetal coagulation defects, and scalp puncture (after pH sampling).

Vacuum devices include a rigid metal cup (Malmstrom), a silicone cup (Kobayashi), and several different disposable plastic cups. Proper placement over the sagittal suture, avoiding the fontanelles, facilitates flexion and descent when traction is applied. Care should be taken that there is no maternal soft tissue interposed.

Successful vaginal delivery rates appear to be higher with vacuum extraction, and maternal and fetal trauma and the need for anesthesia are decreased compared to forceps.

Cesarean Birth

Abdominal delivery results in a 1.5- to 7-fold increase in maternal mortality and a significant increase in morbidity, including endometritis, hemorrhage, thromboembolic events, and urinary tract infection. The cesarean delivery rate is more than 20% in the United States.

The four most common indications for cesarean delivery in the United States are prior cesarean delivery, dystocia, fetal distress, and breech presentation. Cesarean delivery rate has been focused on deliveries.

The assessment of fetal maturity is important in determining the timing of repeat cesarean birth. Amniocentesis should be performed before elective cesarean delivery unless the woman presents in spontaneous labor or the gestational age is 39 weeks or more (normal menstrual cycles.

Low transverse incisions should be routinely used in cesarean deliveries; low vertical incisions are reserved for placenta previa, transverse lie, selected multifetal gestations, and premature breech, particularly with an undeveloped lower uterine segment. Classical cesarean deliveries are rarely performed.

The increasing rate of cesarean delivery over the last two decades has contributed to an increase in the incidence of placenta accreta. This abnormal placentation increases with the number of prior uterine incisions. Special attention should be paid to preoperative preparations, availability of blood.

Vaginal Birth After Cesarean Birth

The rate of uterine separation of a single low transverse incision to be as low as 0.5-1% in women attempting vaginal birth after cesarean delivery and 1-1.3% in women with two or more low transverse incisions.

Careful review of all prior cesarean delivery operative reports is essential in counseling about the safest delivery method. Women with a prior classical or low vertical incision extending into the contractile portion of the uterus should not be allowed to go through labor. For such patients, fetal lung maturity can be confirmed by amniocentesis at 36 weeks of gestation before repeat cesarean birth.

Vaginal delivery should be strongly encouraged in women who have had one previous transverse incision and should be offered to women with two or more such incisions. Women can be counseled about the success rate of 75% with vaginal birth after cesarean delivery. Although higher rates of successful vaginal birth.

Cesarean and Puerperal Hysterectomy

The most common indications for emergent hysterectomy include uterine atony unresponsive to medical management, placenta accreta, uterine rupture, and laceration of major uterine vessels uncontrolled.