Endoscopic retrograde cholangiopancreatography (ERCP) in pregnancy

INTRODUCTION — Pregnancy is associated with an increased risk of gallstone formation. For pregnant patients with gallstone disease complicated by cholangitis or choledocholithiasis (ie, the presence of gallstones within the common bile duct), endoscopic retrograde cholangiopancreatography (ERCP)-guided intervention can be performed safely and successfully.

This topic will discuss procedural considerations, strategies to minimize radiation exposure, and outcomes for pregnant patients who undergo ERCP. Other related topics are presented separately:

●Management of gallstone disease during pregnancy (See "Gallstone diseases in pregnancy".)

●Nonobstetric surgery in pregnant patients (See "Nonobstetric surgery in pregnant patients: Patient counseling, surgical considerations, and obstetric management".)

●Overview of ERCP including indications, patient preparation, post-procedure care, and adverse events (See "Overview of endoscopic retrograde cholangiopancreatography (ERCP) in adults".)

●Anesthesia management for patients undergoing ERCP (See "Anesthesia for gastrointestinal endoscopy in adults".)

●Conditions that are often managed with therapeutic ERCP and a discussion of endoscopic techniques for removing bile duct stones (See "Choledocholithiasis: Clinical manifestations, diagnosis, and management" and "Acute cholangitis: Clinical manifestations, diagnosis, and management" and "Endoscopic management of bile duct stones".)

PREVALENCE — The prevalence of cholelithiasis during pregnancy ranges from 1 to 5 percent, and approximately 1 percent of pregnant patients with gallstone disease develop symptoms [1,2]. In a large population-based study including female patients who were hospitalized for gallstone pancreatitis, nearly 8 percent of patients were pregnant [3].

In addition, biliary tract disease represents one of the most frequent indications for nonobstetric surgery during pregnancy; this is discussed in detail separately. (See "Nonobstetric surgery in pregnant patients: Patient counseling, surgical considerations, and obstetric management".)

PREPROCEDURE EVALUATION — For most patients with gallstone disease and suspected choledocholithiasis, the preprocedure evaluation typically includes radiographic imaging (eg, abdominal ultrasound, magnetic resonance cholangiopancreatography [MRCP]) to confirm the diagnosis [4], and this is discussed separately. (See "Gallstone diseases in pregnancy", section on 'Diagnostic evaluation and findings'.)

If the diagnosis of choledocholithiasis remains uncertain and/or MRCP cannot be performed or is equivocal, endoscopic ultrasound (EUS) is a reasonable alternative [5,6]. EUS can be performed immediately prior to ERCP, and if no biliary stones are identified, the ERCP may not be necessary. In addition, for patients in whom choledocholithiasis is confirmed with EUS, stone characteristics (eg, size, number, location) can be assessed to facilitate the ERCP procedure. (See "Acute calculous cholecystitis: Clinical features and diagnosis", section on 'Additional evaluation in selected patients'.)

PROCEDURAL CONSIDERATIONS

Patient preparation — Preprocedure preparation for pregnant patients undergoing ERCP is similar to that described for nonpregnant patients undergoing ERCP (see "Overview of upper gastrointestinal endoscopy (esophagogastroduodenoscopy)", section on 'Patient preparation'). Specific issues related to pregnancy are addressed here:

●Patient counseling – Patients should be fully informed regarding the risk of procedure-related adverse events, alternatives to ERCP, and radiation risks to themselves and the fetus. Strategies used to minimize radiation exposure are reviewed and documented. (See 'Strategies to minimize radiation exposure' below and "Diagnostic imaging in pregnant and lactating patients".)

The risk of adverse obstetric events related to ERCP during pregnancy appears to be low, although published data are mostly limited to retrospective cohort studies [7-16]. (See 'Outcomes' below.)

●Specialty consultation – Care of the pregnant patient undergoing ERCP requires input from specialists in advanced endoscopy, obstetrics (usually with expertise in high-risk pregnancies), and anesthesia. The decision to monitor fetal heart rate should be individualized and depends on the gestational age of the fetus and available resources [17]. (See "Nonobstetric surgery in pregnant patients: Patient counseling, surgical considerations, and obstetric management", section on 'Fetal heart rate monitoring'.)

Observational data suggest that higher volume endoscopists (ie, ≥200 ERCPs annually) compared with lower volume endoscopists are associated with lower radiation exposure per procedure [18-20]. In a large population-based study, performing ERCP at a teaching hospital compared with a nonteaching hospital was associated with lower rates of post-ERCP pancreatitis (10 versus 15 percent) [19].

●Anesthesia – For pregnant patients, we consult with an anesthesia clinician to provide sedation (typically propofol). When used in standard doses, none of the commonly used anesthetic agents (eg, propofol, midazolam, fentanyl) have been shown to have teratogenic effects in humans [17,21]. (See "Anesthesia for gastrointestinal endoscopy in adults" and "Anesthesia for nondelivery obstetric procedures".)

●Antibiotic prophylaxis – The need for antibiotic prophylaxis is determined by the patient's risk factors for procedure-related infection (table 1) and this is discussed separately. (See "Antibiotic prophylaxis for gastrointestinal endoscopic procedures".)

For pregnant patients, we often prescribe either of the following:

•Amoxicillin-clavulanate 1750 mg orally within 60 minutes prior to procedure, or

•Ampicillin-sulbactam 3 grams intravenously within 60 minutes prior to procedure

Other antibiotics (eg, fluoroquinolones, aminoglycosides), which are typically used in nonpregnant patients, are generally avoided because of potential fetal or maternal toxicity. Antibiotic regimens for nonpregnant patients undergoing ERCP and a general discussion regarding the safety of certain antibiotics in pregnant patients are presented separately. (See "Antibiotic prophylaxis for gastrointestinal endoscopic procedures", section on 'Antibiotic regimens' and "Prenatal care: Patient education, health promotion, and safety of commonly used drugs", section on 'Antibiotics'.)

●Nonsteroidal anti-inflammatory drugs (NSAIDs) – While rectal NSAIDs (eg, indomethacin suppository) are routinely given as a single dose to nonpregnant patients prior to ERCP to reduce the risk of post-ERCP pancreatitis [21], we typically avoid using NSAID prophylaxis for pregnant patients >28 weeks gestation as NSAID use may be associated with adverse pregnancy and infant outcomes (eg, oligohydramnios, premature constriction of the ductus arteriosus). However, the risk of such outcomes after a single dose is very low. For pregnant patients ≤28 weeks, single-dose NSAID prophylaxis is reasonable as the risks associated with NSAID use earlier in pregnancy appear to be low. This is discussed in more detail separately. (See "Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis", section on 'Pharmacologic prophylaxis' and "Safety of rheumatic disease medication use during pregnancy and lactation", section on 'NSAIDs'.)

Timing of ERCP — We do not delay performing ERCP in pregnant patients when it is indicated (eg, symptomatic choledocholithiasis, cholangitis), and limited data suggest that endoscopic intervention is associated with improved outcomes [3,22].

In the database study including over 110,000 female patients who were hospitalized for gallstone pancreatitis discussed above (see 'Prevalence' above), pregnant compared with nonpregnant patients had lower rates of undergoing ERCP (21 versus 25 percent, p<0.001) [3]. The overall risk of 30-day readmission was higher for pregnant compared with nonpregnant patients who were matched for age (odds ratio [OR] 1.95, 95% CI 1.67-2.3). However, for pregnant patients, ERCP during hospital admission compared with no ERCP was associated with lower risk of early readmission (OR 0.40, 95% CI 0.27-0.57) [3]. Similarly, in a retrospective study including 112 pregnant patients with symptomatic choledocholithiasis, procedural intervention (either ERCP or laparoscopic cholecystectomy) compared with medical management alone was associated with lower rates of recurrent biliary symptoms (13 versus 60 percent, p = 0.0002) [22].

Radiation exposure — Fluoroscopy is typically used during ERCP to visualize the biliary tract and to guide biliary cannulation and therapeutic interventions (eg, stone extraction). Studies suggest that fetal radiation exposure during ERCP ranges from <0.0001 to 0.0057 Gy (0.1 to 5.77 mGy) [7,10,11,23-25]. Imaging studies that expose the fetus to <0.05 Gy (50 mGy, 5 rads) have not been associated with increased risk of deterministic effects (eg, fetal anomalies, intellectual disability, growth restriction, pregnancy loss) from ionizing radiation at this dose level [26,27]. However, stochastic effects (eg, childhood cancers) of radiation do not exhibit any threshold dose. Thus, it is possible that smaller doses could increase the risk of childhood cancers, and long-term follow-up studies on radiation-related adverse effects are limited.

In a study including 24 children whose mothers underwent ERCP during pregnancy, there were no developmental delays or malignancies reported after a median of 11 years follow-up [28]. Fetal risks from ionizing radiation and radiation nomenclature are discussed in more detail separately. (See "Diagnostic imaging in pregnant and lactating patients", section on 'Fetal risks' and "Diagnostic imaging in pregnant and lactating patients", section on 'Nomenclature'.)

Strategies to minimize radiation exposure

General measures — Measures to reduce the risk of adverse events to the mother and fetus from radiation exposure include (see "Diagnostic imaging in pregnant and lactating patients"):

●Utilize shielding – Proper shielding should be used to minimize radiation exposure to the uterus [29]. A radiation protection apron shield, if used, should be placed underneath the patient and not draped over the abdomen since the radiation source is typically located underneath the patient when using the standard fluoroscopy C-arm. However, external shielding cannot eliminate fetal exposure due to internally scattered radiation. The uterus should be positioned outside the primary x-ray beam.

●Adjust patient positioning – After approximately 20 weeks of pregnancy, the typical patient positioning for ERCP (ie, prone position) is often not possible because of the gravid uterus. Thus, the left lateral decubitus position, or left pelvic tilt, is required to avoid vena cava or aortic compression [17,30]. Supporting cushions or pillows should be available, and shielding should be adjusted appropriately.

●Limit fluoroscopy time and radiation dose – The following measures will help limit the total fluoroscopy time and radiation dose [23,29,31]:

•Obtain static (spot) films rather than using continuous fluoroscopy

•Minimize magnification of the fluoroscopic image

•Collimate the x-ray beam to the smallest possible field and use other protocols for low-dose radiation (eg, increasing tube voltage, using a low frame rate)

•Use "last image hold" feature to review images rather than using additional fluoroscopy

•Position the image intensifier as close to the patient as possible and place the x-ray tube as far away from the patient as possible.

●Use fetal radiation exposure monitoring – We agree with society guidelines that advise monitoring for fetal radiation exposure if such monitoring equipment is available [31,32]. Dosimeters can be placed on the patient at the expected uterine location to record total radiation dose. Total fluoroscopy time can be recorded if desired and depending on the type of fluoroscopy equipment.

The International Commission on Radiological Protection advises monitoring fetal radiation if the dose is expected to exceed 0.01 Gy (10 mGy), which is higher than the expected fetal radiation exposure during ERCP [7,10,11,23-25] (see 'Radiation exposure' above). However, it is possible that the threshold for monitoring may be exceeded during longer and more complex procedures, and the complexity of a procedure is often difficult to predict. In an observational study including 35 pregnant patients (mean gestational age 19 weeks, range 4 to 35 weeks) who were monitored with thermoluminescent dosimeters during ERCP, the majority of patients (89 percent) had a mean fluoroscopy time of 9 seconds with an estimated fetal radiation dose of <0.0002 (0.2 mGy) [7]. Three patients had fetal radiation dose ranging from 0.0002 to 0.0005 Gy (0.2 to 0.5 mGy), while one patient had fetal radiation dose >0.0005 Gy (0.5 mGy). It should be noted that whether the dose recorded by dosimeters correlated well with the fetal dose is uncertain because the actual fetal doses may vary based on gestational age and the patient's body habitus.

Role of ERCP without radiation — Several investigational approaches have been described that facilitate biliary intervention but do not require fluoroscopy. These modalities may be useful for selected patients in whom radiation exposure is expected to exceed safety limits due to the complexity of the procedure:

●Confirming selective biliary cannulation by aspiration of bile or observing bile flow – An alternative to fluoroscopic-guided cannulation of the bile duct is to visualize bile by aspiration or by observing bile flow through the papilla. As an example, in a series of 21 pregnant patients who had ERCP, confirming bile duct cannulation was done by visually assessing for bile flowing around the wire within the papillary orifice; one case of mild post-ERCP pancreatitis was reported [8]. A limitation of a radiation-free approach is that clearance of the common bile duct cannot be confirmed after stone removal unless direct visualization of the bile duct is performed with a miniature endoscope (ie, cholangioscope).

●Cholangioscopy – Cholangioscopy is typically performed during endoscopic therapy to facilitate extraction of difficult bile duct stones (table 2), but it has also been used to facilitate ERCP without radiation. The bile duct can be visualized with cholangioscopy to achieve stone removal and confirm bile duct clearance [6,8,33-35]. In an observational study including 10 pregnant patients who had ERCP with cholangioscopy, bile duct cannulation was achieved in all patients without fluoroscopy, while therapeutic intervention (eg, stone extraction, stent removal) was successful without fluoroscopy in five patients (50 percent) [35]. (See "Cholangioscopy and pancreatoscopy".)

Potential limitations of ERCP without fluoroscopy include longer procedure times, lack of radiographic visualization to confirm bile duct cannulation, inadvertent cannulation of the cystic duct, and difficulty recognizing conditions such as bile leak, bile duct stricture, or perforation [8]. However, observational data suggested that ERCP without fluoroscopy in pregnant patients was safe and effective. In a systematic review of 27 studies including 1307 pregnant patients who underwent ERCP, radiation-free ERCP was associated with lower overall rates of nonpregnancy-related adverse events (eg, gastrointestinal bleeding, post-ERCP pancreatitis) compared with standard-radiation technique (8 versus 15 percent, respectively) [18]. Rates of fetal or pregnancy-related adverse events were similar between groups. In a systematic review of eight studies including 147 pregnant patients who had ERCP without fluoroscopy, technical success rates were high (≥95 percent), while techniques to avoid radiation exposure varied among studies [36].

POSTPROCEDURE CARE — General considerations for the postprocedure care for pregnant patients (eg, maternal and fetal monitoring) are reviewed separately. (See "Anesthesia for nonobstetric surgery during pregnancy", section on 'Postoperative care'.)

Following ERCP, the patient can usually resume drinking clear fluids after the effects of anesthesia have subsided and then advance to a regular diet as tolerated.

OUTCOMES

Maternal outcomes — Data from mostly smaller retrospective studies suggest that ERCP during pregnancy appears to be safe for the mother and fetus [3,7-16,19,37]. In addition, delaying endoscopic intervention has been associated with increased risk of adverse events (eg, hospital readmission for biliary colic) [3,22]. Thus, pregnant patients who require ERCP should be advised to proceed and avoid delay.

●ERCP pancreatitis – Data suggest that pregnancy may be a risk factor for post-ERCP pancreatitis. In a registry study including 3628 female patients who underwent ERCP, the risk of post-ERCP pancreatitis was higher for pregnant (907 patients) compared with nonpregnant patients (12 versus 5 percent; adjusted odds ratio [OR] 2.8, 95% CI 2.1-3.8) [19]. This is consistent with data from smaller retrospective studies, which also report a higher incidence of post-ERCP pancreatitis among pregnant patients compared with the general population (range: 5 to 16 percent versus 3 to 10 percent, respectively) [9,36,38]. Whether there is a physiologic basis for increased risk of post-ERCP pancreatitis during pregnancy is uncertain, although some prophylactic strategies (eg, NSAIDs) that are used for nonpregnant patients are not typically used during pregnancy. (See 'Patient preparation' above.)

Risk factors for post-ERCP pancreatitis and strategies for prophylaxis are discussed separately. (See "Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis".)

●Maternal death – Maternal death related to ERCP is rare. Among 11 studies including nearly 350 patients who had ERCP during pregnancy [7-16,30], one case of maternal mortality related to post-ERCP pancreatitis that was complicated by acute respiratory distress syndrome was reported [7].

●Other ERCP-related events – Pregnancy does not appear to increase other ERCP-related events (eg, perforation, gastrointestinal bleeding, cholangitis, need for percutaneous drainage) [19].

Fetal outcomes — ERCP during pregnancy has not been associated with an overall increased risk of adverse obstetric or fetal outcomes. However, studies are mostly limited to pregnancy and the immediate postpartum period and do not include longer term follow-up [18,19,37].

●Fetal distress or fetal loss – ERCP does not appear to be associated with fetal distress or fetal loss. In the registry study including 907 pregnant patients who underwent ERCP discussed above (see 'Maternal outcomes' above), rates of fetal distress or fetal loss were low (0.33 and 0.67 percent, respectively), and these rates were similar to the general obstetric population [19].

●Premature labor and/or birth – ERCP also does not appear to be associated with an increased risk of premature labor and/or birth. In the registry study discussed above, estimated rates of preterm labor were lower compared with the general population (1.9 versus 11.5 percent) [19].  

●Neonatal death – Neonatal death is rare, but data are limited. In a series including 23 pregnant patients undergoing ERCP, the only neonatal death was reported in a patient who had three ERCPs during the same pregnancy with minor papilla sphincterotomy and stenting. Each ERCP was complicated by acute pancreatitis requiring inpatient hospitalization [30]. This study illustrates the importance of avoiding multiple ERCPs during pregnancy, if possible.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Endoscopic retrograde cholangiopancreatography (ERCP)".)

SUMMARY AND RECOMMENDATIONS

●General principles – Pregnancy is associated with an increased risk of gallstone formation. For pregnant patients with gallstone disease complicated by choledocholithiasis (ie, the presence of gallstones within the common bile duct) or cholangitis, endoscopic retrograde cholangiopancreatography (ERCP)-guided intervention can be performed safely and successfully. (See 'Introduction' above.)

●Preprocedure evaluation – For most patients with suspected choledocholithiasis, the preprocedure evaluation typically includes radiographic imaging (eg, abdominal ultrasound, magnetic resonance cholangiopancreatography [MRCP]) to confirm the diagnosis. If the diagnosis of choledocholithiasis remains uncertain and/or MRCP cannot be performed, endoscopic ultrasound (EUS) is a reasonable alternative. (See 'Preprocedure evaluation' above and "Choledocholithiasis: Clinical manifestations, diagnosis, and management".)

●Patient preparation – The preprocedure preparation for pregnant patients undergoing ERCP is similar to that described for nonpregnant patients. Issues specific to pregnancy include (see 'Patient preparation' above):

•Multidisciplinary care – Care of the pregnant patient undergoing ERCP requires input from specialists in advanced endoscopy, obstetrics (usually with expertise in high-risk pregnancies), and anesthesia.

•NSAIDs – For pregnant patients >28 weeks gestation, we suggest against pharmacologic prophylaxis with nonsteroidal anti-inflammatory drugs (NSAIDs) (Grade 2C). While some evidence suggests that a single dose of rectally administered NSAID reduces the risk of post-ERCP pancreatitis, NSAIDs have been associated with adverse pregnancy and infant outcomes (eg, oligohydramnios, premature constriction of the ductus arteriosus). However, the risk of such outcomes after a single dose is very low. For pregnant patients ≤28 weeks, single-dose NSAID prophylaxis is reasonable as the risks associated with NSAID use earlier in pregnancy appear to be low.

•Antibiotic prophylaxis – Recommendations for antibiotic prophylaxis are based on a patient's risk factors for procedure-related infection (table 1).

When antibiotic prophylaxis is recommended, we often prescribe amoxicillin-clavulanate or ampicillin-sulbactam within 60 minutes prior to procedure. Other antibiotics (eg, fluoroquinolones, aminoglycosides), which are typically used in nonpregnant patients, are generally avoided because of potential fetal or maternal toxicity.

●Radiation exposure – Fluoroscopy is typically used during ERCP to visualize the biliary tract and to guide biliary cannulation and therapeutic interventions (eg, stone extraction). In general, fetal radiation exposure during ERCP is lower than 0.05 Gy and thus is not associated with an increased risk of fetal anomalies, intellectual disability, growth restriction, or pregnancy loss. (See 'Radiation exposure' above.)

•Measures to reduce the risk of adverse events to the mother and fetus from radiation exposure include shielding, limiting fluoroscopy time, obtaining static (spot) films, collimating the x-ray beam to the smallest possible field, and using a low frame rate. (See 'Strategies to minimize radiation exposure' above.)

•Several techniques have also been studied and show promise for reducing the need for fluoroscopy during ERCP. These include the use of visualization of bile to confirm biliary cannulation and use of cholangioscopy (ie, direct endoscopic visualization of the bile duct with a miniature endoscope). (See 'Role of ERCP without radiation' above.)

●Outcomes – ERCP during pregnancy appears to be safe for the mother and fetus. Specifically, ERCP is not associated with increased risk of premature labor and/or birth compared with the general obstetrical population. In addition, delaying endoscopic intervention has been associated with increased risk of adverse events (eg, hospital readmission for biliary colic). (See 'Outcomes' above.)