Critical Issues in Obstetrics

Educational Objectives

The goal of this program is to improve the management of pregnant women at risk for complications. After hearing and assimilating this program, the clinician will be better able to:

1.   Recognize the importance of thorough documentation in reducing obstetric litigation.

2.   Identify risk factors for fetal macrosomia and shoulder dystocia (SD).

3.   Discuss the proper management of deliveries with SD.

4.   Identify and manage women at risk for placenta previa and accreta.

5.   Explain the risks associated with cesarean delivery by maternal request.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any per­sonal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the faculty and plan­ning committee reported nothing to disclose.

Acknowledgment

Dr. Dildy was recorded at Obstetric Intensive Care: A Simplified Approach, sponsored by Scottsdale Healthcare, held on November 13-15, 2008, in Phoenix, AZ. Dr. Druzin was recorded at Antepartum and Intrapartum Management, sponsored by the University of California San Francisco, School of Medicine, held on June 5-7, 2008 in San Fran­cisco, CA.

Fetal Macrosomia

Gary A. Dildy III, MD, Professor, University of Utah School of Medicine, Department of Obstetrics and Gyne­cology, Salt Lake City, and Director of Maternal-Fetal Medicine, MountainStar Division, Hospital Corporation of America, Salt Lake City

Medical liability issues: as of 2000, median compensatory awards for all medical liability cases >$1 million (in­creasing over time); American College of Obstetricians and Gynecologists (ACOG) survey 2006  —  89% of ACOG Fellows sued at least once; average 2.6 claims; 37% sued during residency; in 2006, at least 50% of obstetricians and gynecologists sued over preceding 3 yr; 5% had 3 cases against them during 3-yr period; 31% of all obstetric and gynecologic medical malpractice cases involved neurologically impaired infants (includes Erb’s palsy and ce­rebral palsy); 38% closed with medical malpractice payout to plaintiff; average payment $1.2 million (in 2006, me­dian payment $2.5 million for childbirth cases); insurance premiums  —  in 2006, average $79,000 annually, with some physicians paying »$400,000 for obstetric liability insurance; Fellow’s survey showed 8% stopped practicing obstetrics (or retired early) because of medicolegal issues; Hospital Corporation of America (HCA) closed claims 2000 to 2005  —  189 obstetric cases; HCA paid $167 million (hospital payments only; does not include physician or legal costs); shoulder dystocia (SD; specifically, brachial plexus palsy) common claim, averaging $500,000; pri­mary cause for payment poor documentation detailing management; poor documentation allows defense to make assumptions about facts of case and prevents rebuttal of plaintiff testimony; SD delivery addendum used in HCA system; SD maneuvers circled in order performed and notations made of whether repeated; also notes who per­formed each maneuver, how much traction applied, and whether fundal pressure applied; information recorded at time of delivery and signed by all health care practitioners involved; becomes part of medical record; speaker rec­ommends familiarity with terminology and position on SD in ACOG’s Practice Patterns and Practice Bulletins

Shoulder dystocia: definitions  —  need to perform extra maneuvers once expulsive forces and general traction do not result in delivery of baby’s body; interval between delivery of head and delivery of body; shoulders being stuck be­hind symphysis pubis and sacral promontory; incidence  —  »1% of all deliveries (depending on how defined and how well documented in hospital records); some propose incidence increasing (possibly because of increasing size of mothers and babies); data suggest incidence underreported; neonatal complications  —  clavicular and humeral fractures; brachial plexus injuries; meconium aspiration; asphyxia; neonatal death; brachial plexus injuries  —  Erb-Duchenne palsy involves spinal roots C5 to C6; Klumpke palsy, C8 to T1; combined palsy, C5 to T1 (nerve stretch­ing, avulsion or rupture); incidence 2 per 1000 deliveries; Erb’s palsy likely to improve over time; however, im­provement unlikely if condition persists at 18 mo; risk factors for SD  —  fetal macrosomia, diabetes mellitus, and previous SD primary risk factors in antepartum period; intrapartum risk factors include mid-pelvic delivery; abnor­malities of labor (rapid labor, as well as prolonged labor); oxytocin augmentation (associated with abnormal labor; £50% of all births in United States stimulated with oxytocin)

Fetal macrosomia: definition of excessive fetal growth  —large for gestational age, with birth weight >90th percen­tile; macrosomia  —  defined as >4500 g by most obstetric providers; ³10% of liveborn neonates in United States weigh ³4000 g; 1.5% of liveborn neonates weigh ³4500 g; risk factors  —  similar to risk for SD; decreased risk as­sociated with smoking; increased risk with positive 50 g glucose screen and negative 3-hr glucose tolerance test; macrosomia common in subpopulation of babies with SD; neonates weighing ³4000 g comprise 50% of all SD cases (defining macrosomia as birth weight of >4000 g); remaining 50%, <4000 g; 10-fold increase in risk for mac­rosomia in SD population; birth weight and diabetes  —  baby of diabetic mother shorter and squatter than baby of same weight of nondiabetic mother, therefore at increased risk for SD; in nondiabetic population with neonate weighing ³4500 g, 20% have SD, compared to 50% in diabetic population; 2.5 relative risk for SD with diabetes and birth weight of ³4500; brachial plexus injury »10% in neonates weighing >5000 g, mortality 2.4%

Brachial plexus injury: data show SD associated with brachial plexus injury in macrosomic neonates; “other mal­presentations” noted in low- and normal-weight neonates; findings suggest causes of brachial plexus injury in addi­tion to SD (however, several methodologic criticisms of this study possible); data show birth weight, diabetes, and operative vaginal delivery as independent predictors of SD; per study data, 70% of neonates without SD had ³1 risk factor for SD and 30% had ³2 risk factors; speaker’s data suggest that in neonates with SD, 95% had ³1 risk factor for SD; 85% had ³2 risk factors, and 65% had ³3 risk factors; decision analysis of elective cesarean delivery for fe­tal macrosomia  —  data show 3695 cesarean deliveries necessary to prevent 1 brachial plexus injury in neonates of nondiabetic population with estimated fetal weight (EFW) ³4500 g; would increase cesarean delivery rate from 19% to 28% at cost of $8.7 million; decision analysis of diabetic population showed ³400 cesarean deliveries of ne­onates with EFW >4000 g necessary to prevent one permanent brachial plexus injury

Clinical management: once SD recognized, request additional obstetric help (eg, nurses, anesthesia staff, pediatric staff); combination of traction on neonate’s head and fundal pressure associated with high frequency of neonatal trauma; fundal pressure unadvisable under most circumstances; speaker’s policy to discontinue applying traction and to attempt other maneuvers if head delivered and neonate not moving; obstetric textbooks recommend “gentle downward traction,” but plaintiff’s attorneys often argue “gentle downward traction more than gentle”

Interventions: McRoberts maneuver  —  exaggerated flexion of legs; decreases angle of inclination of pelvis; rotates pelvis toward mother’s head and flattens out sacrum; suprapubic pressure  —  pressure applied above pubic bone may rotate shoulders wedged in anterior-posterior position into oblique position; speaker cautions against mistak­enly charting suprapubic pressure as fundal pressure; Woods maneuver  —  rotational maneuver; speaker does not recommend fundal pressure component (suggests using maternal expulsive forces instead); Rubin’s maneuver  —  pressure applied along posterior aspect of shoulder reduces diameter of shoulders by bringing clavicles forward; when performing rotation maneuver, attempt to place hand behind neonate’s head (theoretically reducing width of shoulders with rotation); posterior arm delivery    —  acceptable and effective in some cases; associated with humeral fracture; data show reduction of obstruction factor by ³2 cm relative to McRoberts maneuver; other salvage maneuvers  —  speaker recommends familiarity with all-fours position and Zavanelli maneuver; symphysiotomy not recommended

ACOG recommendations: although diagnosis of fetal macrosomia imprecise, consider prophylactic cesarean deliv­ery for suspected fetal macrosomia with EFW >5000 g in women without diabetes and >4500 g in women with di­abetes; patient with identifiable risk factors for SD  —speaker recommends obtaining EFW (by ultrasonography [US], Leopold’s maneuver, or asking multiparous mother her estimate); speaker discusses pros and cons of cesar­ean delivery with patient; ACOG states suspected fetal macrosomia does not contraindicate attempted vaginal birth after cesarean (VBAC) delivery (however, vaginal birth after cesarean  against policy of many hospitals); SD can­not be predicted or prevented because accurate methods for identifying fetuses likely to experience complication not possible (biggest limitation estimating birth weight); no evidence for benefit of elective induction of labor for all women suspected of carrying macrosomal fetuses (does not reduce incidence of SD or Erb’s palsy, and will in­crease cesarean delivery rate); speaker offers labor induction to patient with favorable cervix and good Bishop scores at 39 wk (with good dating); no evidence any one maneuver superior to another, but McRoberts maneuver and suprapubic pressure appear to work most of time with minimal degree of risk for injury; speaker recommends dictating notes in cases with potential for long-term maternal or fetal injury; rectify any discrepancies between nursing notes and clinician’s notes; Joint Commission on the Accreditation of Healthcare Organizations (JCAHO) recommends that hospitals perform drills for obstetric emergencies (if not done, used as evidence by plaintiff’s at­torneys)

Risk for SD and permanent brachial plexus injury: assessment of risk based on diabetes status combined with EFW and other obstetric factors; eg, 22-yr-old prima gravida with gestational diabetes and EFW of 4.1 kg has 25% chance for SD; risk for Erb’s palsy of any type »20%, and risk for permanent associated disability 10%; overall, <1% chance child will have permanent brachial plexus injury

Management and Risks of
Multiple Cesarean Deliveries

Maurice Druzin, MD, Charles B. and Ann L. Johnson Professor and Vice-Chair, Department of Obstetrics and Gynecology; Chief, Division of Maternal-Fetal Medicine, Stanford University Medical Center, Palo Alto, Cali­fornia

Cesarean delivery on maternal request (CDMR): defined as cesarean delivery in absence of any medical or other obstetric indication; cesarean delivery rates rising in United States (29% in 2004; data show current rate »30%); “perfect storm of medical, legal, and personal choice issues and lack of opposing view” (Flamm); VBAC  —  encouraged in 1960s and 1970s in attempt to decrease rate of cesarean deliveries; recently has gained greater ac­ceptance as legitimate option for delivery; National Institutes of Health State-of-the Science Conference on CDMR  —  weak evidence for most factors favoring CDMR; only significant finding of large study was greater risk for placenta previa with CDMR; ACOG has not taken stand on issue of CDMR

Risks in future pregnancies: increased risk for placenta previa and placenta accreta; increased risk for uterine rup­ture; complications of multiple abdominal surgeries; risk for placenta accreta 40% in woman with previa and his­tory of 3 cesarean deliveries, and 60% with previa and history of 4 cesarean deliveries

Types of placenta previa: complete previa  —  completely covers cervical os; partial previa  —  extends to cervical os, but does not have both anterior and posterior component; complicates »4 per 1000 pregnancies >20 wk gestation; 10% risk with history of previous cesarean delivery; risk increases with history of previous uterine surgery (eg, myomotomy, multiple dilation and curettage [D&C]) procedures, advanced maternal age, and parity

Clinical presentation: painless vaginal bleeding; some incidentally detected by US; bleeding likely to occur during third trimester, with delivery at mean gestational age of 36 wk; some patients may present with bleeding at <30 wk gestation (more likely to require premature delivery and cause increased perinatal morbidity and mortality); abrup­tio placentae (premature separation of normally implanted placenta) not same as placenta previa; presence of ab­dominal pain distinguishes abruption from placenta previa;  speaker recommends initiation of tocolytic therapy for early bleeding placenta previa and early mild abruptio placentae (controversial in literature)

Ultrasonography: transabdominal US  —diagnosis of anterior placenta previa made only after mother empties blad­der and placental position confirmed; anterior previa more likely placenta accreta (particularly with history of ce­sarean delivery); transvaginal US  —  gold standard for diagnosis of placenta previa; safe and effective technique; probe does not need to come into contact with cervix for diagnosis; diagnosis possible with abdominal US alone in >90% of cases

Management of placenta previa: stable preterm patients  —subset of patients with placenta over cervical os at 10 to 20 wk gestation resolve without special management; the longer previa persists, the greater the likelihood of pres­ence at delivery; pregnancy can be prolonged by 1 mo in >50% of patients with symptomatic previa

Stanford protocol for bleeding placenta previa (24 to 37 wk): admit to labor and delivery; tocolysis given if con­tractions present (controversial); steroids administered with early labor; prescribe bedrest with bathroom privileges; consider discharging patient with reliable transportation and stable social situation; do not discharge if placenta ac­creta suspected; preparation for delivery  —amniocentesis performed at 36 wk gestation to assess fetal lung matu­rity; alternatively (per study data), can forgo amniocentesis if steroids given and patient monitored for bleeding; deliver at 36 wk; counsel patient and obtain consent for hysterectomy; schedule cesarean delivery during regular hours to ensure adequate personnel (ie, anesthesiologist, surgical backup, interventional radiology consultant,  blood bank consultant); avoid disruption of placenta when entering uterus (review preoperative US); individualize surgical management (may need vertical or high transverse incision, or hysterectomy)

Placenta accreta: complicates 5% to 10% of pregnancies with placenta previa; 40% risk with >2 cesarean deliveries; 10-fold increase in incidence in last 50 yr; frequency 1 in 2500 deliveries; be prepared for massive blood replace­ment; diagnosed on US before delivery (hypoechoic boundary between placenta and uterine wall); data show trans­vaginal US just as accurate as MRI; profuse life-threatening hemorrhage major complication of placenta accreta; primary treatment for placenta accreta hysterectomy; other interventions experimental and theoretical; potentially lethal disease with significant morbidity; interventions include expectant management and subsequent manual re­moval of placenta (speaker considers highly risky); treatment with methotrexate considered investigational; blad­der involvement  (placenta percreta)  — only situation in which speaker recommends leaving placenta in situ; activation of rapid response team recommended for any patient at high risk for obstetric hemorrhage

Suggested Reading

ACOG. Shoulder Dystocia. Practice Patterns No 7. Washington, DC: ACOG, 1997; ACOG. Fetal Macrosomia. Prac­tice Bulletin No. 22. Washington, DC: ACOG, 2000; ACOG. Shoulder Dystocia. Practice Bulletin No 40. Washington, DC: ACOG, 2002; ACOG. Placenta accreta No. 266. Washington, DC: ACOG; Acker DB et al: Risk factors for shoul­der dystocia. Obstet Gynecology 66:762, 1985; Belfort MA et al: Prediction of shoulder dystocia using multivariate analysis. Am J Perinatol 24:5, 2007; Clark SL et al: Reducing obstetric litigation through alterations in practice. Obstet Gynecol 112:1279, 2008; Dildy GA et al: Shoulder dystocia: risk identification. Clin Obstet Gynecol 43:265, 2000; Gawande A: The Score: How childbirth went industrial. The New Yorker, 2006; Gilbert WM et al: Associated fac­tors in 1611 cases of brachial plexus injury. Obstet Gynecol 93:536, 1999; Gonik B et al: Shoulder dystocia recogni­tion: differences in neonatal risks for injury. Am J Perinatol 8:31, 1991; Kayem G et al: Conservative versus extirpative management in cases of placenta accreta. Obstet Gynecol 204:531, 2004;  Meenan AL et al: A new (old) maneuver for the management of shoulder dystocia. J Fam Pract 32:625, 1991; Rouse DJ et al: The effectiveness and costs of elective cesarean delivery for fetal macrosomia diagnosed by ultrasound. JAMA 18:1480, 1996.