Cervical insufficiency is the inability to sustain a pregnancy to term due to dysfunction of the uterine cervix. It is characterized by painless dilation and/or shortening of the cervix during the second trimester of pregnancy, resulting in preterm delivery and recurring pregnancy loss. The incidence of cervical insufficiency is difficult to determine due to poorly defined clinical criteria for the diagnosis. Instead, the frequency of cervical cerclage is used as a surrogate to estimate the incidence of cervical insufficiency. Martin et al. reported that the rate of cervical cerclage is of 4.4/1,000 live births in the United States (1). Risk factors for the development of cervical insufficiency include familial inheritance (e.g., connective tissue disorders such as Ehlers–Danlos and Marfan syndromes), African-American race, intrauterine infections, hormonal abnormalities, congenital uterine abnormalities (e.g., in utero maternal exposure to diethylstilbestrol), and diagnostic or therapeutic surgical interventions (2,3,4,5,6). Structural damage to the uterine cervix from biopsies, cauterization, conization, and mechanical dilation and curettage are also associated with cervical insufficiency.

Diagnosis of cervical insufficiency is one of exclusion, based on medical history and clinical assessment. History of previous pregnancy losses during the second trimester, cervical shortening, painless cervical dilation, and the presence of known risk factors should point toward this diagnosis. The patient may report vaginal pressure, caused by the protruding membranes, urinary frequency, and increased mucoid vaginal discharge. If left untreated, eventual rupture of fetal membrane may occur, which will likely proceed to the delivery of a premature and/or nonviable neonate (7).

Ultrasound can aid in assessing cervical length, as the risk of spontaneous preterm labor/delivery is higher with shorter sonographic cervical length in the mid-second trimester (8). Since only a small fraction of all patients who will have a spontaneous preterm birth have a shortened cervix in the mid-second trimester, surveillance of the cervical length by ultrasound should only be considered in patients at high risk for cervical insufficiency (7,9).

Although controversial, management of cervical insufficiency is centered on cerclage placement. Current evidence suggests that the subgroups of patients that may benefit from cerclage placement are those with clinical presentation of acute cervical insufficiency, or those with a previous history of cervical insufficiency and progressive shortening of the cervix as demonstrated by ultrasound (7,10,11). Other therapies that have been used in combination with cervical cerclage for the management of cervical insufficiency include administration of progesterone, tocolytic drugs, and perioperative antibiotics (12,13,14). In a study published by the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network, the authors concluded that, when compared to placebo, weekly injections of progesterone resulted in a substantial reduction in the rate of recurrent preterm delivery in the at-risk patient (14). Information regarding other adjunct therapies is less well defined.

Cerclage placement can be considered elective, urgent, or an emergency (15). Elective cerclage is typically performed between 13 and 16 weeks of gestation in asymptomatic patients with a history of cervical insufficiency or multiple risk factors. Urgent cerclage is performed after ultrasonographic findings of decreasing cervical length (<25 mm) in asymptomatic patients between 20 and 24 weeks of gestation. Emergency cerclage is performed for symptomatic patients with advanced cervical dilation (>2 cm), with or without bulging of the fetal membranes, in the absence of labor. Emergency cerclage is controversial since it carries a higher procedural risk of fetal membrane rupture. The timing for cervical cerclages in relation to neonatal outcome is also debated, as it has not been adequately studied in large, randomized trials.

The optimal surgical technique for cerclage placement is unclear. In general, two approaches are used: transvaginal or transabdominal. The McDonald and the modified Shirodkar are the most common techniques for cerclage placement. Both of these surgical techniques are done by a transvaginal approach and have similar fetal outcomes (16). The McDonald cerclage is less invasive with a purse-string suture placed at the cervicovaginal junction, without bladder mobilization (Fig. 15-1). The Shirodkar cerclage differs from the McDonald in that the suture is placed following bladder mobilization, to allow for a higher insertion level (15,17). In addition, removal of a McDonald cerclage can usually be accomplished without the need for pain medication, whereas a Shirodkar cerclage is more invasive, and removal typically requires analgesia and possibly anesthesia. Transabdominal cerclage, which requires a laparotomy or laparoscopy, serves as an alternative for patients in whom placement of a transvaginal cerclage is exceedingly challenging (e.g., previous cervical surgery) or those who have had a failed transvaginal approach. A systematic review
comparing pregnancy outcomes after a transabdominal versus a transvaginal cerclage in patients with a failed transvaginal cerclage during a previous pregnancy concluded that the risk of perinatal death and delivery before 24 weeks was lower for women who received a transabdominal cerclage (6.0% vs. 12.5%, respectively) (18). However, transabdominal cerclage was also associated with a higher incidence of serious operative complications compared to the transvaginal approach (3.4% vs. 0%; 95% CI 0.01% to 6.8%). Cesarean delivery is typically the mode of delivery for patients with a transabdominal cerclage.

The most frequent procedural risks associated with cervical cerclages include iatrogenic rupture of membranes, chorioamnionitis, hemorrhage, cervical stenosis, and cervical laceration. Cervical cerclages also increase the number of obstetrical interventions (e.g., administration of tocolytics, cesarean delivery, etc.) and the need for repeat cerclage in the future (19). Moreover, a meta-analysis of eight studies demonstrated that women who underwent cervical cerclage placement had a slightly higher rate of cesarean delivery compared to women who received other forms of treatment for cervical incompetency (relative risk [RR] 1.19; 95% CI 1.01 to 1.40) (20). Cervical cerclage should not be performed in the setting of maternal hemodynamic instability, rupture of fetal membranes, intra-amniotic or vaginal infection, abnormal placentation, active maternal or fetal bleeding, uterine contractions or preterm labor, intrauterine fetal demise, major fetal abnormality incompatible with life, and gestational age >28 weeks (19).

The anesthetic management for cerclage placement will depend on the technical approach and timing of the procedure. Transvaginal cerclages are typically performed with spinal, epidural, or general anesthesia, while the transabdominal is more frequently done under general anesthesia. The procedure is usually performed in the outpatient setting, requires 30 to 45 minutes for completion, and a T10 to L1 and S2 to S4 sensory blockade is desired to provide coverage of the cervix, vagina, and perineum. Among the different neuraxial techniques, spinal anesthesia is the preferred choice as it provides a faster and denser block compared to epidural anesthesia. A hyperbaric solution of lidocaine 30 to 70 mg, hyperbaric bupivacaine 5.25 to 12 mg, or mepivacaine 45 to 60 mg are reasonable options for spinal anesthesia. Lee et al. observed that the spread of analgesic effects of spinally administered hyperbaric bupivacaine was enhanced in women in the second trimester compared to the nonpregnant state (21). Lipophilic opioids (e.g., fentanyl 10 to 20 μg) are often used to reduce local anesthetic requirements and duration (22,23).

Although lidocaine may be a better option for cervical cerclage placement in terms of its duration, increased concern for transient neurologic syndrome (TNS) after intrathecal administration has dissuaded many providers from using hyperbaric lidocaine for cerclage placement. Indeed, the incidence of TNS in nonpregnant patients is higher with lidocaine than bupivacaine, and this risk of TNS is not decreased by decreasing the concentration (24,25). Although not completely exempt from the risk of TNS, parturients may be at decreased risk compared to nonpregnant patients. In a prospective study, Wong and Slavenas reported a 0% incidence (95% CI 0% to 4.5%) of TNS in 67 parturients who received hyperbaric 5% lidocaine for cerclage placement (26). Although no cases of TNS were detected, the 95% confidence interval is still less than the 10% to 37% incidence reported in the nonobstetric population (25). In another study, Aouad et al. randomized patients undergoing cesarean delivery to spinal anesthesia with hyperbaric 5% lidocaine or hyperbaric 0.75% bupivacaine, reporting a 0% incidence of TNS (95% CI 0% to 3%) (27). Finally, Philip et al. randomized patients to receive intrathecal hyperbaric 5% lidocaine versus hyperbaric 0.75% bupivacaine for postpartum tubal ligation (28). The authors reported no difference in the incidence of TNS with lidocaine versus bupivacaine (3% vs. 7%) in this patient population. Overall, the evidence suggests that the use of hyperbaric lidocaine intrathecally in pregnant women is likely safe in terms of TNS risk and that this risk is likely less than that in the nonpregnant population, and comparable to the intrathecal administration of other local anesthetics.

Low-dose epidural anesthesia can also be used to provide surgical anesthesia for cervical cerclages (29). Lidocaine 2% with epinephrine 5 μg/mL, 10 to 15 mL, typically provides adequate sensory coverage; fentanyl 50 to 100 μg can be added through the epidural catheter to increase the density of the neuraxial block. Finally, paracervical block is another option for a McDonald cerclage, but it has fallen out of favor due to the potential for fetal bradycardia after local anesthesia injection, with a reported incidence of 2% to 10% (30,31,32). Regardless of the anesthetic technique, postoperative analgesic requirements are none to minimal after transvaginal placement of a cervical cerclage.

General anesthesia is more likely to be used for emergency cerclage as the use of volatile anesthetics provides uterine relaxation, potentially reducing cervical protrusion of fetal membranes. In addition, this anesthetic technique does not require a sitting or lateral position for administration, positions which may not be possible if protruding fetal membranes are present. Mask anesthesia or a laryngeal mask airway (LMA) is an acceptable option for healthy, fasted patients before 18 to 20 weeks of gestation. However, women of 18 to 20 weeks of gestation and later are at increased risk of aspiration, and therefore should undergo endotracheal intubation. If intubation is performed, beware that coughing
and vomiting increase intra-abdominal and intrauterine pressures, precipitating or worsening protrusion of the fetal membranes, or even promoting membrane rupture. Steps should be taken to ensure these perianesthesia events are avoided.

The incidence of breech presentation for term, singleton pregnancies is estimated to be between 3% and 4% (33). Breech fetal presentation occurs when the fetal head is in the fundus of the uterus with the buttocks, legs, or feet presenting. There are three main types of breech presentations: frank, complete, and incomplete (Fig. 15-2). A frank breech occurs when the fetus’s lower extremities are flexed at the hips and extended at the knees so that the feet are against the face and the buttocks only are the presenting part. A complete breech occurs when the fetus’s hips and knees are flexed but the feet do not extend below the buttocks. An incomplete breech (also known as footling breech) occurs when one or both fetal lower extremities are extended and one or both feet present in the vagina.

Although the causes of breech presentation are unclear, there are both fetal and maternal factors that increase this likelihood (Table 15-1). A relative increase in the uterine volume (e.g., prematurity, low birth weight) prevents the accommodation of the fetus to the shape of the uterine cavity leading to malpresentation. Multiparity, multiple gestation, and polyhydramnios are also associated with breech presentation due to increased uterine relaxation. Finally, limited uterine space (e.g., pelvic tumors, uterine anomalies, abnormal placentation, oligohydramnios) and fetal muscular disorders (e.g., muscular dystrophy) can result in fetal malpresentation. In all of these situations, cephalic rotation of the fetus may not occur prior to delivery (34,35,36).

Multiple delivery options exist for fetuses in breech presentation, including cesarean delivery, trial of labor with vaginal delivery, or ECV, each with its respective benefits and risks. The Term Breech Trial (TBT) randomized more than 2,000 women with a singleton fetus in breech presentation to cesarean or vaginal delivery (37), and demonstrated better neonatal outcomes after a cesarean delivery than after vaginal delivery for breech-presenting fetuses, (1.6% vs. 5%, respectively); (RR 0.33; 95% CI 0.19 to 0.56; P < 0.0001). Since this publication, the breech vaginal delivery rate has declined. In a retrospective study that assessed the vaginal delivery rate of breech term pregnancies in the 8 years before and after the TBT, the authors observed that the rate of vaginal delivery in nulliparous and multiparous women decreased from 15.3% to 7.2% in the former group, and from approximately 32.6% to 14.8% in the latter group (38).

Since cesarean and vaginal breech deliveries increase maternal and perinatal morbidity and mortality compared to vaginal vertex deliveries. The American College of Obstetricians and Gynecologists (ACOG) recommends the use of ECV to rotate the fetus to a vertex presentation at term (37,39,40,41). ECV is an obstetrical procedure performed for the purpose of changing a nonvertex (typically breech) fetal presentation to vertex by external rotation through the maternal abdominal wall. According to a systematic review of randomized controlled trials, the overall success rate of ECV is 60%, with results ranging from 35% to 85% depending if tocolytics are used (42,43). If successful, ECV not only reduces the need for cesarean delivery, but also results in improved maternal and perinatal outcomes (44,45).

Tan et al. studied the cost-effectiveness, from society’s perspective, of ECV compared to schedule cesarean delivery for term breech presentation. Cost-effectiveness, defined by a certain quality-adjusted life year, was less for ECV compared to scheduled cesarean deliveries for breech presentation. However, this only held true if the probability of successful ECV was >32% (71). Moreover, Bolaji and colleague demonstrated that even if the use of a neuraxial technique would increase the number of successful ECV by 15%, this would result in more than $33,000 in savings due to the decreased rates of cesarean delivery and its complications (72).

ECV should be attempted in the operating room or in the labor and delivery unit with an operating room available in case an emergent cesarean delivery becomes necessary. However, considering the cost of utilizing an operating room, it may be cost effective to perform this procedure in the labor and delivery unit. In addition, both mother and fetus should be monitored throughout the procedure. Blood pressure and pulse oximetry should be used for the mother, while fetal monitoring should be performed before and after each ECV attempt. Moreover, left uterine displacement should be ensured whenever the patient is supine, and providers should have the ability to rapidly treat hypotension if it develops. Finally, ECV should be performed at times that do not detract from the care of the rest of the patients in the labor and delivery unit (Table 15-3).

Tubal sterilization is a highly effective form of female birth control, with a failure rate of <1%. Due to its reliability and permanence, this form of contraception was utilized by 16.7% of women in the United States between 2006 and 2008, second only to oral contraception in frequency of use among women (Fig. 15-6) (73). It is also one of the most commonly performed operations in the United States with 643,000 patients undergoing this procedure in 2006, approximately 340,000 of which are performed postpartum (74). Since more than 50% of tubal sterilizations are performed during the early postpartum period, anesthesiologists providing obstetric care to women are frequently called upon to provide care for this procedure.