Chronic Pancreatitis in Pregnancy

Overview

Pathophysiology

Etiology in Pregnancy

• Yamada's Textbook of Gastroenterology; Creasy & Resnik's Maternal-Fetal Medicine, p. 1598

• Elevated estrogen increases cholesterol saturation of bile → gallstone formation
• Progesterone causes gallbladder hypomotility → bile stasis
• Elevated triglyceride levels (physiologic in pregnancy) can reach pancreatitis-inducing thresholds, especially in women with underlying lipid disorders

Clinical Features

• Presentation is not significantly altered by pregnancy
• Most common in the third trimester and puerperium
• Symptoms: epigastric pain (may radiate to flanks/back/shoulders), nausea, vomiting, abdominal tenderness
• Some patients present with nausea/vomiting as the only complaint
• Associated findings: mild fever, leukocytosis, adynamic ileus on imaging
• Chronic CP features in pregnancy also include: steatorrhea, weight loss, malabsorption, and pancreatogenic diabetes (type 3c)
• Creasy & Resnik's Maternal-Fetal Medicine, p. 1599

Diagnosis

Laboratory

Imaging

• Ultrasound - first-line; safe in pregnancy; excellent for gallstone detection, less reliable for pancreatic parenchyma
• MRCP - preferred when ultrasound is indeterminate; confirms diagnosis, identifies ductal changes, pseudocysts, choledocholithiasis; avoids radiation; performed successfully during pregnancy
• CT - reserved for severe cases where fetal radiation risk is justified; identifies necrosis, pseudocysts, calcifications
• ERCP - therapeutic only (not diagnostic) during pregnancy; used for bile duct stone removal

Management

General Principles (same as non-pregnant)

1. Bowel rest ± nasogastric decompression during acute flares
2. IV fluid resuscitation with electrolyte replacement
3. Analgesia - Meperidine (pethidine) is traditionally preferred over morphine as it does not constrict the sphincter of Oddi; however, opioids should be used with caution in pregnancy
4. Fetal monitoring - continuous during acute flares
5. Positioning - lateral decubitus to avoid IVC compression

Specific Considerations in Pregnancy

• Creasy & Resnik's Maternal-Fetal Medicine, p. 1599-1600; Schwartz's Principles of Surgery

Endoscopic / Surgical Options

• ERCP with sphincterotomy during pregnancy limits radiation by using fluoroscopy sparingly; can prevent recurrent biliary pancreatitis and allow cholecystectomy to be deferred
• However, sphincterotomy alone carries a 25-50% risk of gallstone complications within 2 years
• Surgical drainage procedures (Puestow, Frey, Berne) are rarely performed during pregnancy but may be necessary in refractory cases

Maternal and Fetal Outcomes

• For mild disease responsive to conservative management: prognosis for mother and fetus is excellent
• For severe pancreatitis (necrotizing, multiorgan failure): significant maternal and fetal morbidity/mortality
• Perinatal mortality has decreased to ~3.6% with modern neonatal care; maternal mortality <1%
• Risk of preterm labor is increased during acute flares
• CP patients may have pre-existing malnutrition that compounds fetal growth risk
• Pancreatic necrosis can progress to SIRS and multiorgan failure
• 50-70% of untreated biliary pancreatitis will have recurrent episodes if managed conservatively without addressing the biliary cause
• Yamada's Textbook of Gastroenterology; Creasy & Resnik's Maternal-Fetal Medicine

Multidisciplinary Care

• Maternal-fetal medicine / Obstetrics
• Gastroenterology / Hepatology
• Surgery (HPB surgeon)
• Dietetics/Nutrition
• Endocrinology (if pancreatogenic diabetes)
• Neonatology (for preterm risk)

Key Points Summary

Pancreatogenic Diabetes (Type 3c Diabetes Mellitus / T3cDM)

Definition

It is estimated to affect 5-10% of all patients with diabetes but is frequently misdiagnosed as Type 2 DM. - Vonderau & Desai, JAAPA 2022 (PMID 36219100)

Causes (Etiologies)

• Robbins, Cotran & Kumar Pathologic Basis of Disease; Goldman-Cecil Medicine; Schwartz's Principles of Surgery

Pathophysiology

Islet Pathology

• Islets are relatively resistant to destruction in chronic pancreatitis - acinar tissue and fibrosis predominate first
• Islets become smaller, isolated from their vascular network by surrounding fibrosis
• With progressive disease, endocrine failure eventually follows exocrine failure
• Frank diabetes is seen in ~20% initially, but impaired glucose metabolism is detectable in up to 70% of CP patients
• In alcoholic CP, diabetes develops in 83% within 25 years; >50% ultimately need insulin
• Point prevalence of diabetes in CP: ~40%; cumulative lifetime prevalence: >80%
• Yamada's Textbook of Gastroenterology; Sleisenger & Fordtran's GI and Liver Disease

The Three-Hormone Deficiency

The Paradox of Dual Insulin Sensitivity

• Enhanced peripheral sensitivity to insulin (muscle and adipocytes) - due to insulin deficiency upregulating insulin receptors, as in Type 1 DM
• Decreased hepatic sensitivity to insulin (hepatic insulin resistance) - mediated by PP deficiency
• This results in hepatic glucose overproduction when insulin is insufficient, but severe peripheral hypoglycemia when insulin is barely in excess

Incretin Deficiency

• GIP and GLP-1 (primary incretin hormones) mediating postprandial insulin secretion are also impaired in T3cDM
• Likely due to impaired nutrient absorption from coexisting exocrine pancreatic insufficiency (EPI)
• Reduced incretin response = reduced postprandial insulin secretion on top of already-depleted beta cells
• Yamada's Textbook of Gastroenterology

Comparison: T3cDM vs T1DM vs T2DM

• Sleisenger & Fordtran GI and Liver Disease; Schwartz's Principles of Surgery

Clinical Features

• Hyperglycemia - often persistent, poorly controlled
• Hypoglycemic episodes - frequent, prolonged, severe (hallmark)
• Weight loss and malnutrition (coexisting exocrine insufficiency)
• Steatorrhea / fat malabsorption
• Abdominal pain (if due to chronic pancreatitis)
• Microangiopathic complications (retinopathy, neuropathy) - occur at similar frequency as in T1DM
• Nephropathy and ketoacidosis - relatively uncommon

Diagnosis

Diagnostic Criteria for T3cDM (requires ALL major criteria + at least one minor criterion)

1. Exocrine pancreatic insufficiency (EPI) confirmed by low fecal elastase or 72-h fecal fat
2. Abnormal pancreatic imaging (CT/MRI/MRCP/EUS showing structural changes)
3. Absence of T1DM autoantibodies (anti-GAD, anti-islet cell antibodies)

• Impaired beta-cell function (low C-peptide, insulin)
• No insulin resistance (normal or low HOMA-IR)
• Impaired incretin secretion (low GIP/GLP-1)
• Low serum levels of fat-soluble vitamins (A, D, E, K)
• Reduced PP response to mixed meal

Management

General Principles

1. Glycemic control
2. Prevention of hypoglycemia
3. Treatment of coexisting exocrine insufficiency (PERT)
4. Nutritional support

Step-by-Step Pharmacological Approach

• Yamada's Textbook of Gastroenterology

Insulin Therapy - Special Considerations

• Start low, titrate slowly - risk of severe hypoglycemia
• Target HbA1c carefully (7-8% may be safer than strict <7%)
• Insulin pump therapy has been studied; addition of subcutaneous PP infusion reduced insulin requirements
• Avoid long-acting insulin as the sole agent without rapid-acting cover at meals
• Always co-prescribe pancreatic enzyme replacement therapy (PERT) - uncontrolled EPI worsens glycemic variability by impairing nutrient absorption

PERT and Nutrition

• All T3cDM patients with coexisting EPI need PERT with every meal (pancrelipase)
• PERT improves glucose variability by restoring predictable nutrient absorption
• Annual screening for fat-soluble vitamin deficiencies (A, D, E, K) - deficiencies are common (Vitamin D deficient in ~58%)
• Fat-restricted diet is generally recommended; adequate protein and calories to prevent sarcopenia

Experimental / Future

• Pancreatic Polypeptide (PP) analogs / PP receptor agonists - currently under investigation to specifically correct hepatic insulin resistance in T3cDM - Schwartz's Principles of Surgery, 11e

Natural History and Complications

• Progression: From impaired glucose tolerance → overt diabetes over years to decades (median 11-26 years from CP onset depending on etiology)
• Alcoholic CP: ~20 years median; late-onset idiopathic CP: ~12 years
• Pancreatic cancer risk: T3cDM in chronic pancreatitis carries significant risk of PDAC; new-onset T3cDM in a patient without prior CP diagnosis should prompt pancreatic cancer screening
• Microangiopathy (retinopathy, neuropathy) comparable to T1DM
• Malnutrition-related complications

Key Summary Points