- Email: [email protected]
Treatment of suspected fetal macrosomia: A cost-effectiveness analysis
American Journal of Obstetrics and Gynecology (2005) 193, 1035–9
www.ajog.org
Treatment of suspected fetal macrosomia: A cost-effectiveness analysis Melissa A. Herbst, MD* Department of Obstetrics and Gynecology, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH Received for publication February 28, 2005; revised May 25, 2005; accepted June 6, 2005
KEY WORDS Macrosomia Induction Labor management Cost-effectiveness
Objective: Treatment of fetal macrosomia presents challenges to practitioners because a potential outcome of shoulder dystocia with permanent brachial plexus injury is costly both to families and to society. Practitioner options include labor induction, elective cesarean delivery, or expectant treatment. We performed a cost-effective analysis to evaluate the treatment strategies that were preferred to prevent the most permanent brachial plexus injuries with the least amount of dollars spent. Study design: Using decision analysis techniques, we compared 3 strategies for an infant with an estimated fetal weight of 4500 g: labor induction, elective cesarean delivery, and expectant treatment. The following baseline assumptions were made: Probability of shoulder dystocia in vaginal delivery, .145; labor induction, .03; cesarean delivery, .001; probability of plexus injury, .18; probability of permanent injury, .067; probability of cesarean delivery with induction, .35; with expectant treatment, .33; cost of vaginal delivery, $3376; cost of elective cesarean delivery, $5200; cost of cesarean delivery with labor, $6500; lifetime cost of brachial plexus injury, $1,000,000. Sensitivity analyses were performed. Results: Under baseline assumptions for an infant who weighs 4500 g, expectant treatment is the preferred strategy at a cost of $4014.33 per injury-free child, compared with elective cesarean delivery at a cost of $5212.06 and an induction cost of $5165.08. Sensitivity analyses revealed that, if the incidence of shoulder dystocia and permanent injury remained !10%, expectant treatment is the preferred method. Conclusion: Fetal macrosomia with possible permanent plexus injuries is a concern. Our analysis would suggest that expectant treatment is the most cost-effective approach to this problem. Ó 2005 Mosby, Inc. All rights reserved.
Treatment of suspected fetal macrosomia at term is challenging. Diagnosis by clinical examination and ultrasonography is difficult and may be inaccurate.1 Presented at the Twenty-Fifth Annual Meeting of the Society for Maternal Fetal Medicine, Reno, Nevada, February 7-12, 2005. * Reprint requests: Melissa A. Herbst, MD, Maternal Fetal Medicine Services of Utah, 1140 E 3900 S, Suite 390, Salt Lake City, UT 84121. E-mail: [email protected] 0002-9378/$ - see front matter Ó 2005 Mosby, Inc. All rights reserved. doi:10.1016/j.ajog.2005.06.030
Options for care include expectant treatment, induction of labor, and elective cesarean delivery.2 In selected patients, one of these options may be easily chosen as clearly appropriate; but for most patients, there is no obvious best choice.1-5 Among the most feared complications of macrosomia is shoulder dystocia, an unpredictable yet serious event that may result in permanent brachial plexus injury.4,6,7 In an effort to assist practitioners in choosing among these options, we performed
1036 Table
Herbst Assumptions for cost analysis of delivery method for suspected fetal macrosomia
Variable Cesarean delivery Elective induction Expectant management Shoulder dystocia Elective cesarean delivery Elective induction Cesarean delivery Vaginal delivery Expectant management Cesarean delivery Vaginal delivery25 Plexus injury Permanent injury Costs Brachial plexus rehabilitation Vaginal delivery Cesarean delivery Before labor After labor
Baseline
Range
Reference
0.35 0.33
0.17-0.57 0.08-0.35
1,2,17-19,21 1,17-19
0.001
0-0.03
2,7,13,20
0.003 0.145
0.05-0.21
2,7,13 1,19,22,23
0.003 0.03 0.18 0.067
0.01-0.14 0.1-2.6 0.01-0.194
7,13 19,22,24 1,2,18,20,23 1,2,7,20
$950 $3376
$475-$1900 $2733-$4291
2 2
$5200 $6500
$4160-$6240 $5200-$7800
2 2
a cost-effectiveness analysis that was based on a clinical model of expected outcomes.
Material and methods We performed a cost-effectiveness analysis from the perspective of a third-party payer. Because this research used information from published literature with no direct patient contact, no Institutional Review Board approval was required. Healthcare costs of several treatment strategies for the delivery of a pregnant woman without pregestational or gestational diabetes mellitus with a fetus who is suspected to weigh O4500 g were evaluated and compared with expected outcomes of permanent brachial plexus injury avoided (ie, dollars per injury avoided). The medical intervention that was evaluated was the method of delivery for suspected fetal macrosomia in pregnancy. The population included pregnant women, without pregestational or gestational diabetes mellitus with suspected fetal macrosomia that was based on ultrasound evaluation. The desired outcome was an avoided permanent brachial plexus injury with the least amount of dollars spent. We used actual reimbursement costs, not charges, for our analysis. Avoidance of permanent brachial plexus injury is the measure that we used to calculate the effectiveness of the competing treatment strategies. An electronic literature search with the use of Pub Med that included the terms macrosomia, induction, delivery, shoulder dystocia, brachial plexus injury, cost analysis, and cesarean was performed to obtain references that concerned suspected fetal macrosomia and mode of delivery. All available evidence regarding potential effectiveness of
the different strategies was gathered. Economic data that related to the cost of the components of each strategy was obtained. All data were included in the cost analysis. Baseline assumptions were developed from the published literature for the analysis (Table). A decision tree was generated with decision analysis software (data 4.0 for health professionals; TreeAge Software Inc, Williamstown, Mass) to compare the treatment strategies (Figure). The baseline assumptions in the decision analysis included the incidence of cesarean delivery in those women who underwent induction is 35% and in women with expectant treatment is 33%. The risk of shoulder dystocia in women who delivered by cesarean delivery before labor is 0.1% and after labor is 0.3%; the risk of shoulder dystocia in women who were delivered vaginally after induction is 14%, with 3% having a shoulder dystocia if the delivery was vaginal in those women with expectant treatment (Table). We assumed that all patients received the diagnosis of suspected fetal macrosomia through the performance of an ultrasound examination with an estimated fetal weight of O4500 g. The costs of vaginal delivery, cesarean delivery before labor, cesarean delivery after labor, and transient brachial plexus rehabilitation were included as described by Rouse and Owen.1 However, the cost of the long-term effects of permanent brachial plexus injury and the indirect costs (the potential loss of income of family members assisting with the care of the child) were not considered in our analysis. Our model considered a pregnant woman without pregestational or gestational diabetes mellitus whose fetus is suspected to weigh O4500 g. Three delivery strategies were used (Figure).
Herbst
1037
Figure
Decision tree for delivery management for patients with suspected fetal macrosomia.
Elective cesarean delivery Patients who fulfilled the American College of Obstetricians and Gynecologists guidelines would be scheduled for elective cesarean delivery at 39 weeks of gestation. Cesarean delivery would be performed in the standard fashion. If a shoulder dystocia occurred, it was handled in the standard fashion, and the child would be evaluated further in the nursery for possible injury. If an injury was noted, the child would be referred to physical therapy for continued care and follow up. Determination of permanence was done at 1 year.
Induction at 38 to 39 weeks of gestation Patients would be scheduled for induction between 38 and 39 weeks of gestation with the method of induction chosen by provider. Cesarean delivery would be performed on the basis of obstetric indications. For those who were delivered vaginally, only nonoperative deliv-
eries were included, because this type of delivery is known to increase the risk of shoulder dystocia in patients with suspected fetal macrosomia.1,4,8-10 Shoulder dystocia was treated in the standard fashion. Infants would be evaluated further in the nursery for possible injury and, if an injury were found, were to be treated in the same manner as described earlier.
Expectant treatment Patients would be followed by providers with standard prenatal care. Patients went into labor spontaneously or labor was induced according to standard American College of Obstetricians and Gynecologists guidelines. Labor management and infant follow-up examinations were as described previously.
Results Our model included 100 pregnant women without maternal or gestational diabetes mellitus with suspected
1038 fetal macrosomia. Under our baseline assumptions, expectant treatment of labor onset was the most costeffective at $40,144.33 per permanent brachial plexus injury that was avoided versus labor induction ($5165.08 per injury avoided) and elective cesarean delivery ($5212.06 per injury avoided). Because the incidence of shoulder dystocia with vaginal delivery varies in the literature, we wanted to verify our findings over this range. Thus, sensitivity analyses were performed that varied the probability of shoulder dystocia from 0.145 to 0.99. With the incidence of permanent injury so low, sensitivity analyses were performed with a probability range of 0.067 to 0.1. Expectant treatment continued to dominate if the incidence of shoulder dystocia and permanent injury remained !10%.
Comment The management of delivery for pregnant women with suspected fetal macrosomia is an ongoing and difficult issue. The major area of concern is that of shoulder dystocia and brachial plexus injury. Although rare, shoulder dystocia is associated with multiple neonatal complications, both orthopedic and neurologic in nature. Neonatal fractures of the clavicle and/or humerus occur in 1% to 2% of vaginal deliveries, with an increased incidence that is associated with shoulder dystocia.11 Yet with simple supportive therapy, fractures heal quickly with no permanent disability.11 Conversely, neurologic complications can be more serious. Although brachial plexus injury and Erb’s palsy are found in 0.5 to 1.89 per 1000 vaginal deliveries that are complicated by shoulder dystocia, the risk increases to 4% to 8% in patients with fetal macrosomia.4 Although most brachial plexus injuries resolve with rehabilitation within the first year, even after surgery, 1% to 5% result in permanent disability.5,12 With these concerns, many providers have opted for either planned cesarean delivery or early induction of labor instead of expectant treatment to avoid continued fetal growth and thus an increased possibility of shoulder dystocia. The costs of such strategies rarely are considered. As this analysis has shown, with the risk of shoulder dystocia and plexus injury in each treatment model accounted for, expectant treatment of labor is the most cost-effective in the avoidance of permanent brachial plexus injury for patients without maternal or gestational diabetes mellitus with suspected fetal macrosomia. Currently, providers very often offer cesarean delivery or induction of labor for patients with suspected fetal macrosomia. However, previous research supports the contrary. Clinical research, in conjunction with costeffective analyses, have lead to the consensus that elective cesarean delivery is only beneficial for those patients whose fetus is suspected to be O5000 g in nondiabetic women.1,4,13 Research regarding the beneficial effect of induction of labor for those with suspected fetal macro-
Herbst somia has been varied. Yet, the meta-analysis by SanchezRamos et al2 showed a significant increase in the rate of cesarean delivery in women who undergo induction of labor, with no significant decrease in the rate of shoulder dystocia. It has been reported that the induction of labor for suspected macrosomia does not improve maternal or fetal outcome.4 Although our research found expectant treatment to be the preferred strategy, there are several cost factors that are not included in our analysis. These include length of stay, nursing cost, cost of antenatal surveillance, and impact on future pregnancy outcome. The cost that is related to length of stay would most likely impact the elective cesarean delivery and induction of labor protocols. Patients who were delivered by cesarean delivery have postoperative stays between 2 and 3 days longer than those patients who were delivered vaginally. For those women who undergo induction of labor, length of stay before delivery is generally 24 hours longer than those women in spontaneous labor. Therefore, these factors along with the associated nursing care cost would most likely continue to support the expectant treatment protocol. However, the expectant treatment protocol possibly would include outpatient antepartum fetal surveillance. Currently, this consists of biweekly non–stress testing and biophysical profiles, along with continued outpatient provider visits, and a small percentage within this group would require induction of labor at 41 weeks of gestation. However, it is doubtful that the additional small outpatient cost would overcome the inpatient costs that are incurred by the elective cesarean delivery or the induction of labor protocol. With a cost savings of $1200.00 per permanent injury avoided through the use of expectant treatment, there remains a possibility that providers or patients may desire an elective cesarean delivery. With the decrease in severe morbidity and mortality rates that are associated with cesarean delivery found in modern obstetrics, elective cesarean delivery may be of little immediate medical risk or significant healthcare cost. However, the impact on future pregnancies and healthcare dollars may be significant. The risk of uterine rupture with future attempt at vaginal delivery after cesarean, although small, can lead to significant maternal and fetal complications, which include fetal death. In regards to future repeat cesarean deliveries, each delivery gives rise to an increase in operative time, along with an increased risk of organ injury, infection, and abnormal placentation and its associated complications.14-16 Thus, although some clinicians may see the initial cost savings through expectant treatment to be small, the lifelong saving in regards to both healthcare cost and medical complications is significant. Even with all cost factors included, one must consider the limitations of ultrasound evaluation in the determination of fetal weight. It has been shown that ultrasound prediction of fetal weight in infants who weigh O4000 g
Herbst has a positive predictive value between 45% and 71%, with a negative predictive value between 97% and 98%.1,17 This gives rise to an overestimation of fetal weight. Therefore, some patients with suspected fetal macrosomia would deliver smaller infants with a decreased risk of shoulder dystocia, and costs that would otherwise accrue through either the induction or elective cesarean delivery strategy because of this overestimation of fetal weight would continue to support the expectant treatment strategy. The diagnosis of suspected fetal macrosomia is becoming more prevalent. The increased risk of complications within this group, along with the concerns regarding the growing healthcare costs, makes the treatment of these patients of utmost importance. Elective cesarean delivery, induction of labor, and expectant management of labor have long been viable healthcare options. Numerous research regarding the risks and benefits of each method has been conducted. However, with the growing concern regarding the cost of healthcare, our research that evaluates these 3 strategies on the basis of cost-effectiveness offers support to the use of expectant treatment of labor onset in those patients with suspected fetal macrosomia for the avoidance of permanent brachial plexus injury. I thank Nora M. Doyle, MD, MPH, and Susan M. Ramin, MD, for their assistance in the statistical analysis of this project and their invaluable support.
References 1. Rouse DJ, Owen J. Prophylactic cesarean delivery for fetal macrosomia diagnosed by means of ultrasonography: A Faustian bargain? Am J Obstet Gynecol 1999;181:332-8. 2. Sanchez-Ramos L, Bernstein S, Kaunitz A. Expectant management versus labor induction for suspected fetal macrosomia: a systematic review. Obstet Gynecol 2002;100:997-1002. 3. Rouse DJ, Owen J, Goldenberg RL, Cliver SP. The effectiveness and costs of elective cesarean delivery for fetal macrosomia diagnosed by ultrasound. JAMA 1996;276:1480-6. 4. American College of Obstetricians and Gynecologist. Fetal Macrosomia. Washington (DC): The College; 2000. ACOG Practice Bulletin no.: 22. 5. Piatt JH. Birth injuries of the brachial plexus. Pediatr Clin N Am 2004;51:421-40. 6. Langer O, Berkus MD, Huff RW, Samueloff A. Shoulder dystocia: Should the fetus weighing R4000 grams be delivered by cesarean section? Am J Obstet Gynecol 1991;165:831-7.
1039 7. McFarland LV, Raskin M, Daling JR, Benedetti TJ. Erb/ Duchenne’s palsy: a consequence of fetal macrosomia and method of delivery. Obstet Gynecol 1986;68:784-8. 8. McFarland M, Hod M, Piper JM, Xenakis EM, Langer O. Are labor abnormalities more common in shoulder dystocia? Am J Obstet Gynecol 1995;173:1211-4. 9. Bolfill JA, Rust OA, Devidas M, Roberts WE, Morrison JC, Martin JN. Shoulder dystocia and operative vaginal delivery. J Matern Fetal Med 1997;6:220-4. 10. Baskett MB, Allen AC. Perinatal implications of shoulder dystocia. Obstet Gynecol 1995;86:14-7. 11. Lam MH, Wong GY, Lao TT. Reappraisal of neonatal clavicular fracture: relationship between infant size and neonatal morbidity. Obstet Gynecol 2002;100:115-9. 12. Hardy AE. Birth injuries of the brachial plexus: incidence and prognosis. J Bone Joint Surg 1981;63B:98-101. 13. Graham EM. A retrospective analysis of Erb’s palsy cases and their relation to birth weight and trauma at delivery. J Matern Fetal Med 1997;6:1-5. 14. Phipps MG, Watabe B, Clemons JL, Weitzen S, Myers DL. Risk factors for bladder injury during cesarean delivery. Obstet Gynecol 2005;105:156-60. 15. Mankuta DD, Leshno MM, Menasche MM, Brezis MM. Vaginal birth after cesarean section: Trial of labor or repeat cesarean section? A decision analysis. Am J Obstet Gynecol 2003;189: 714-9. 16. Kirkinen P. Multiple caesarean sections: outcomes and complications. BJOG 1988;95:778-82. 17. Rossavik IK, Joslin GL. Macrosomatia and ultrasonography: What Is the Problem? S Med J 1993;86:1129-32. 18. Leaphart WL, Meyer MC, Capeless EL. Labor induction with a prenatal diagnosis of fetal macrosomia. J Matern Fetal Med 1997;6:99-102. 19. Gonen O, Rosen DJ, Dolfin Z, Tepper R, Markov S, Fejgin MD. Induction of labor versus expectant management in macrosomia: a randomized study. Obstet Gynecol 1997;89:913-7. 20. Combs CA, Singh NB, Khoury JC. Elective induction versus spontaneous labor after sonographic diagnosis of fetal macrosomia. Obstet Gynecol 1993;81:492-6. 21. Kolderup LB, Laros RK, Musci TJ. Incidence of persistent birth injury in macrosomic infants: association with mode of delivery. Am J Obstet Gynecol 1997;177:37-41. 22. Herbst MA, Mercer B, Milluzzi C. Induction with suspected macrosomia: impact on the course of labor. Am J Obstet Gynecol 2003;189:S203. 23. Tey A, Eriksen NL, Blanco JD. A Prospective randomized trial of induction versus expectant management in no diabetic pregnancies with fetal macrosomia [abstract]. Am J Obstet Gynecol 1995; 172:293. 24. Lipscomb KR, Gregory K, Shaw K. The outcome of macrosomic infants weighing at least 4500 grams: Los Angeles County C University of Southern California experience. Obstet Gynecol 1995;85:558-64. 25. Modanlou HD, Dorchester WL, Thorosian A, Freeman RK. Macrosomia: maternal, fetal, and neonatal implications. Obstet Gynecol 1980;55:420-4.
www.ajog.org
Treatment of suspected fetal macrosomia: A cost-effectiveness analysis Melissa A. Herbst, MD* Department of Obstetrics and Gynecology, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH Received for publication February 28, 2005; revised May 25, 2005; accepted June 6, 2005
KEY WORDS Macrosomia Induction Labor management Cost-effectiveness
Objective: Treatment of fetal macrosomia presents challenges to practitioners because a potential outcome of shoulder dystocia with permanent brachial plexus injury is costly both to families and to society. Practitioner options include labor induction, elective cesarean delivery, or expectant treatment. We performed a cost-effective analysis to evaluate the treatment strategies that were preferred to prevent the most permanent brachial plexus injuries with the least amount of dollars spent. Study design: Using decision analysis techniques, we compared 3 strategies for an infant with an estimated fetal weight of 4500 g: labor induction, elective cesarean delivery, and expectant treatment. The following baseline assumptions were made: Probability of shoulder dystocia in vaginal delivery, .145; labor induction, .03; cesarean delivery, .001; probability of plexus injury, .18; probability of permanent injury, .067; probability of cesarean delivery with induction, .35; with expectant treatment, .33; cost of vaginal delivery, $3376; cost of elective cesarean delivery, $5200; cost of cesarean delivery with labor, $6500; lifetime cost of brachial plexus injury, $1,000,000. Sensitivity analyses were performed. Results: Under baseline assumptions for an infant who weighs 4500 g, expectant treatment is the preferred strategy at a cost of $4014.33 per injury-free child, compared with elective cesarean delivery at a cost of $5212.06 and an induction cost of $5165.08. Sensitivity analyses revealed that, if the incidence of shoulder dystocia and permanent injury remained !10%, expectant treatment is the preferred method. Conclusion: Fetal macrosomia with possible permanent plexus injuries is a concern. Our analysis would suggest that expectant treatment is the most cost-effective approach to this problem. Ó 2005 Mosby, Inc. All rights reserved.
Treatment of suspected fetal macrosomia at term is challenging. Diagnosis by clinical examination and ultrasonography is difficult and may be inaccurate.1 Presented at the Twenty-Fifth Annual Meeting of the Society for Maternal Fetal Medicine, Reno, Nevada, February 7-12, 2005. * Reprint requests: Melissa A. Herbst, MD, Maternal Fetal Medicine Services of Utah, 1140 E 3900 S, Suite 390, Salt Lake City, UT 84121. E-mail: [email protected] 0002-9378/$ - see front matter Ó 2005 Mosby, Inc. All rights reserved. doi:10.1016/j.ajog.2005.06.030
Options for care include expectant treatment, induction of labor, and elective cesarean delivery.2 In selected patients, one of these options may be easily chosen as clearly appropriate; but for most patients, there is no obvious best choice.1-5 Among the most feared complications of macrosomia is shoulder dystocia, an unpredictable yet serious event that may result in permanent brachial plexus injury.4,6,7 In an effort to assist practitioners in choosing among these options, we performed
1036 Table
Herbst Assumptions for cost analysis of delivery method for suspected fetal macrosomia
Variable Cesarean delivery Elective induction Expectant management Shoulder dystocia Elective cesarean delivery Elective induction Cesarean delivery Vaginal delivery Expectant management Cesarean delivery Vaginal delivery25 Plexus injury Permanent injury Costs Brachial plexus rehabilitation Vaginal delivery Cesarean delivery Before labor After labor
Baseline
Range
Reference
0.35 0.33
0.17-0.57 0.08-0.35
1,2,17-19,21 1,17-19
0.001
0-0.03
2,7,13,20
0.003 0.145
0.05-0.21
2,7,13 1,19,22,23
0.003 0.03 0.18 0.067
0.01-0.14 0.1-2.6 0.01-0.194
7,13 19,22,24 1,2,18,20,23 1,2,7,20
$950 $3376
$475-$1900 $2733-$4291
2 2
$5200 $6500
$4160-$6240 $5200-$7800
2 2
a cost-effectiveness analysis that was based on a clinical model of expected outcomes.
Material and methods We performed a cost-effectiveness analysis from the perspective of a third-party payer. Because this research used information from published literature with no direct patient contact, no Institutional Review Board approval was required. Healthcare costs of several treatment strategies for the delivery of a pregnant woman without pregestational or gestational diabetes mellitus with a fetus who is suspected to weigh O4500 g were evaluated and compared with expected outcomes of permanent brachial plexus injury avoided (ie, dollars per injury avoided). The medical intervention that was evaluated was the method of delivery for suspected fetal macrosomia in pregnancy. The population included pregnant women, without pregestational or gestational diabetes mellitus with suspected fetal macrosomia that was based on ultrasound evaluation. The desired outcome was an avoided permanent brachial plexus injury with the least amount of dollars spent. We used actual reimbursement costs, not charges, for our analysis. Avoidance of permanent brachial plexus injury is the measure that we used to calculate the effectiveness of the competing treatment strategies. An electronic literature search with the use of Pub Med that included the terms macrosomia, induction, delivery, shoulder dystocia, brachial plexus injury, cost analysis, and cesarean was performed to obtain references that concerned suspected fetal macrosomia and mode of delivery. All available evidence regarding potential effectiveness of
the different strategies was gathered. Economic data that related to the cost of the components of each strategy was obtained. All data were included in the cost analysis. Baseline assumptions were developed from the published literature for the analysis (Table). A decision tree was generated with decision analysis software (data 4.0 for health professionals; TreeAge Software Inc, Williamstown, Mass) to compare the treatment strategies (Figure). The baseline assumptions in the decision analysis included the incidence of cesarean delivery in those women who underwent induction is 35% and in women with expectant treatment is 33%. The risk of shoulder dystocia in women who delivered by cesarean delivery before labor is 0.1% and after labor is 0.3%; the risk of shoulder dystocia in women who were delivered vaginally after induction is 14%, with 3% having a shoulder dystocia if the delivery was vaginal in those women with expectant treatment (Table). We assumed that all patients received the diagnosis of suspected fetal macrosomia through the performance of an ultrasound examination with an estimated fetal weight of O4500 g. The costs of vaginal delivery, cesarean delivery before labor, cesarean delivery after labor, and transient brachial plexus rehabilitation were included as described by Rouse and Owen.1 However, the cost of the long-term effects of permanent brachial plexus injury and the indirect costs (the potential loss of income of family members assisting with the care of the child) were not considered in our analysis. Our model considered a pregnant woman without pregestational or gestational diabetes mellitus whose fetus is suspected to weigh O4500 g. Three delivery strategies were used (Figure).
Herbst
1037
Figure
Decision tree for delivery management for patients with suspected fetal macrosomia.
Elective cesarean delivery Patients who fulfilled the American College of Obstetricians and Gynecologists guidelines would be scheduled for elective cesarean delivery at 39 weeks of gestation. Cesarean delivery would be performed in the standard fashion. If a shoulder dystocia occurred, it was handled in the standard fashion, and the child would be evaluated further in the nursery for possible injury. If an injury was noted, the child would be referred to physical therapy for continued care and follow up. Determination of permanence was done at 1 year.
Induction at 38 to 39 weeks of gestation Patients would be scheduled for induction between 38 and 39 weeks of gestation with the method of induction chosen by provider. Cesarean delivery would be performed on the basis of obstetric indications. For those who were delivered vaginally, only nonoperative deliv-
eries were included, because this type of delivery is known to increase the risk of shoulder dystocia in patients with suspected fetal macrosomia.1,4,8-10 Shoulder dystocia was treated in the standard fashion. Infants would be evaluated further in the nursery for possible injury and, if an injury were found, were to be treated in the same manner as described earlier.
Expectant treatment Patients would be followed by providers with standard prenatal care. Patients went into labor spontaneously or labor was induced according to standard American College of Obstetricians and Gynecologists guidelines. Labor management and infant follow-up examinations were as described previously.
Results Our model included 100 pregnant women without maternal or gestational diabetes mellitus with suspected
1038 fetal macrosomia. Under our baseline assumptions, expectant treatment of labor onset was the most costeffective at $40,144.33 per permanent brachial plexus injury that was avoided versus labor induction ($5165.08 per injury avoided) and elective cesarean delivery ($5212.06 per injury avoided). Because the incidence of shoulder dystocia with vaginal delivery varies in the literature, we wanted to verify our findings over this range. Thus, sensitivity analyses were performed that varied the probability of shoulder dystocia from 0.145 to 0.99. With the incidence of permanent injury so low, sensitivity analyses were performed with a probability range of 0.067 to 0.1. Expectant treatment continued to dominate if the incidence of shoulder dystocia and permanent injury remained !10%.
Comment The management of delivery for pregnant women with suspected fetal macrosomia is an ongoing and difficult issue. The major area of concern is that of shoulder dystocia and brachial plexus injury. Although rare, shoulder dystocia is associated with multiple neonatal complications, both orthopedic and neurologic in nature. Neonatal fractures of the clavicle and/or humerus occur in 1% to 2% of vaginal deliveries, with an increased incidence that is associated with shoulder dystocia.11 Yet with simple supportive therapy, fractures heal quickly with no permanent disability.11 Conversely, neurologic complications can be more serious. Although brachial plexus injury and Erb’s palsy are found in 0.5 to 1.89 per 1000 vaginal deliveries that are complicated by shoulder dystocia, the risk increases to 4% to 8% in patients with fetal macrosomia.4 Although most brachial plexus injuries resolve with rehabilitation within the first year, even after surgery, 1% to 5% result in permanent disability.5,12 With these concerns, many providers have opted for either planned cesarean delivery or early induction of labor instead of expectant treatment to avoid continued fetal growth and thus an increased possibility of shoulder dystocia. The costs of such strategies rarely are considered. As this analysis has shown, with the risk of shoulder dystocia and plexus injury in each treatment model accounted for, expectant treatment of labor is the most cost-effective in the avoidance of permanent brachial plexus injury for patients without maternal or gestational diabetes mellitus with suspected fetal macrosomia. Currently, providers very often offer cesarean delivery or induction of labor for patients with suspected fetal macrosomia. However, previous research supports the contrary. Clinical research, in conjunction with costeffective analyses, have lead to the consensus that elective cesarean delivery is only beneficial for those patients whose fetus is suspected to be O5000 g in nondiabetic women.1,4,13 Research regarding the beneficial effect of induction of labor for those with suspected fetal macro-
Herbst somia has been varied. Yet, the meta-analysis by SanchezRamos et al2 showed a significant increase in the rate of cesarean delivery in women who undergo induction of labor, with no significant decrease in the rate of shoulder dystocia. It has been reported that the induction of labor for suspected macrosomia does not improve maternal or fetal outcome.4 Although our research found expectant treatment to be the preferred strategy, there are several cost factors that are not included in our analysis. These include length of stay, nursing cost, cost of antenatal surveillance, and impact on future pregnancy outcome. The cost that is related to length of stay would most likely impact the elective cesarean delivery and induction of labor protocols. Patients who were delivered by cesarean delivery have postoperative stays between 2 and 3 days longer than those patients who were delivered vaginally. For those women who undergo induction of labor, length of stay before delivery is generally 24 hours longer than those women in spontaneous labor. Therefore, these factors along with the associated nursing care cost would most likely continue to support the expectant treatment protocol. However, the expectant treatment protocol possibly would include outpatient antepartum fetal surveillance. Currently, this consists of biweekly non–stress testing and biophysical profiles, along with continued outpatient provider visits, and a small percentage within this group would require induction of labor at 41 weeks of gestation. However, it is doubtful that the additional small outpatient cost would overcome the inpatient costs that are incurred by the elective cesarean delivery or the induction of labor protocol. With a cost savings of $1200.00 per permanent injury avoided through the use of expectant treatment, there remains a possibility that providers or patients may desire an elective cesarean delivery. With the decrease in severe morbidity and mortality rates that are associated with cesarean delivery found in modern obstetrics, elective cesarean delivery may be of little immediate medical risk or significant healthcare cost. However, the impact on future pregnancies and healthcare dollars may be significant. The risk of uterine rupture with future attempt at vaginal delivery after cesarean, although small, can lead to significant maternal and fetal complications, which include fetal death. In regards to future repeat cesarean deliveries, each delivery gives rise to an increase in operative time, along with an increased risk of organ injury, infection, and abnormal placentation and its associated complications.14-16 Thus, although some clinicians may see the initial cost savings through expectant treatment to be small, the lifelong saving in regards to both healthcare cost and medical complications is significant. Even with all cost factors included, one must consider the limitations of ultrasound evaluation in the determination of fetal weight. It has been shown that ultrasound prediction of fetal weight in infants who weigh O4000 g
Herbst has a positive predictive value between 45% and 71%, with a negative predictive value between 97% and 98%.1,17 This gives rise to an overestimation of fetal weight. Therefore, some patients with suspected fetal macrosomia would deliver smaller infants with a decreased risk of shoulder dystocia, and costs that would otherwise accrue through either the induction or elective cesarean delivery strategy because of this overestimation of fetal weight would continue to support the expectant treatment strategy. The diagnosis of suspected fetal macrosomia is becoming more prevalent. The increased risk of complications within this group, along with the concerns regarding the growing healthcare costs, makes the treatment of these patients of utmost importance. Elective cesarean delivery, induction of labor, and expectant management of labor have long been viable healthcare options. Numerous research regarding the risks and benefits of each method has been conducted. However, with the growing concern regarding the cost of healthcare, our research that evaluates these 3 strategies on the basis of cost-effectiveness offers support to the use of expectant treatment of labor onset in those patients with suspected fetal macrosomia for the avoidance of permanent brachial plexus injury. I thank Nora M. Doyle, MD, MPH, and Susan M. Ramin, MD, for their assistance in the statistical analysis of this project and their invaluable support.
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