Acute Abdomen and Pregnancy

Updated: Apr 08, 2022
  • Author: Dana Taylor, MD, FACS; Chief Editor: Carl V Smith, MD  more...
  • Print


Acute abdomen, as it presents with pregnancy, has many possible causes. Clearly, the case of a pregnant patient with acute abdomen is a clinical scenario that overlaps specialties. There should be no hesitation to involve a surgeon, an obstetrician/gynecologist, and a specialist in maternal-fetal medicine when this challenging situation arises.

As defined in the 27th edition of Stedman's Medical Dictionary, acute abdomen is "any serious acute intra-abdominal condition attended by pain, tenderness, and muscular rigidity, and for which emergency surgery must be considered."

Any cause for acute abdomen can occur coincident with pregnancy. Some clinical conditions are more likely to occur in pregnancy; others are specific to pregnancy. Thus, a wide range of possible differential diagnoses should be considered.

The diagnostic approach to pregnant patients with severe abdominal pain is very similar to that for nonpregnant patients with acute abdomen. However, the physiologic changes associated with pregnancy must be considered in the interpretation of findings from the history and physical examination. [1] In addition, there is a reluctance to use certain radiologic investigations for fear of harming the fetus. 

When evaluating the gravid patient with acute abdominal pain, remember that the reference ranges for some very commonly used laboratory tests are altered in pregnancy. These changes can make the initial evaluation process somewhat more difficult. For example, an inflammatory process such as appendicitis would be expected to produce an elevated white blood cell (WBC) count. Yet pregnancy alone can produce WBC counts ranging from 6000 to 16,000/μL in the second and third trimesters and from 20,000 to 30,000/μL in early labor. [2]



Causes incidental to pregnancy

Gastrointestinal (GI) causes of acute abdomen that are incidental to pregnancy include the following:

Genitourinary (GU) causes of acute abdomen that are incidental to pregnancy include the following:

Vascular causes of acute abdomen that are incidental to pregnancy include the following:

Respiratory causes of acute abdomen that are incidental to pregnancy include the following:

Additional causes of acute abdomen that are incidental to pregnancy include the following:

Causes associated with pregnancy

Pregnancy-associated conditions that cause acute abdomen include the following:

Conditions resulting from pregnancy that cause acute abdomen in early pregnancy include the following:

Conditions resulting from pregnancy that cause acute abdomen in later pregnancy include the following:

  • Red degeneration of myoma
  • Torsion of pedunculated myoma
  • Placental abruption
  • Placenta percreta
  • HELLP (hemolysis, elevated liver function, and low platelets) syndrome – Spontaneous rupture of the liver
  • Uterine rupture



Obtain as detailed a history as possible regarding the time of onset, duration, intensity, and character of the pain, as well as any associated symptoms. [11] Establishing the gestational age early in the evaluation is essential because the likelihood of different etiologies changes with different gestational ages. Accurate knowledge of gestational age is required to make appropriate decisions regarding fetal viability and the need for fetal evaluation.

It should be kept in mind that nausea, vomiting, constipation, increased frequency of urination, and pelvic or abdominal discomfort are frequently experienced in normal pregnancy. The patient should be asked to differentiate these normal pregnancy changes from the acute event for which she presents. [12]

It is also important to ascertain the time course and acuteness of onset by asking the following questions:

  • Did the pain begin suddenly or did it grow in intensity?
  • Is it steady or crampy, dull and aching, or sharp and stabbing?
  • Did it occur before or after a meal?
  • Did it awaken the patient from sleep?
  • How well is it localized, and has the location changed?
  • Is it associated with nausea and vomiting, and if so, did these symptoms begin before or after the pain?
  • Does anything make the pain worse or better?

Physical examination

Upon physical examination, findings may be less prominent than they would be in nonpregnant patients with the same disorder. [13, 14] Peritoneal signs are often absent in pregnancy because of the lifting and stretching of the anterior abdominal wall. The underlying inflammation has no direct contact with the parietal peritoneum, and this prevents the muscular response or guarding that would otherwise be expected. [15] The uterus can also obstruct and inhibit the movement of the omentum to an area of inflammation, distorting the clinical picture.

To help distinguish extrauterine tenderness from uterine tenderness, performing the examination with the patient in the right or left decubitus position, thereby displacing the gravid uterus to one side, may prove helpful.

In performing a physical examination of the gravid abdomen, it is essential to recall the changing positions of the intra-abdominal contents at different gestational ages. For example, in patients in early pregnancy and nonpregnant patients, the appendix is located at the McBurney point; however, after the first trimester, the appendix is progressively displaced upward and laterally until, in late pregnancy, it is closer to the gallbladder. [16]

Such alterations in physical assessment can delay diagnosis, and many authorities attribute the increased morbidity and mortality of acute abdomen in gravid patients to this delay.

Fetal considerations

When evaluating the gravid patient, the clinician must evaluate two patients at the same time, the mother and the fetus. Before the gestational age at which independent viability (if delivery were to occur) is generally expected, evaluation of the fetus can be limited to documentation of the presence or absence of fetal heart tones by means of Doppler ultrasonography (US). When the fetus is considered viable, a more thorough evaluation is required. The age of viability varies from institution to institution. The fetal heart rate and uterine tone should be monitored continuously throughout the period of evaluation.

A nonreassuring tracing or evidence of fetal distress may suggest an obstetric etiology for the acute abdomen (eg, placental abruption or uterine rupture [17] ). A reassuring tracing allows the evaluation to continue at an appropriate pace. Monitoring for uterine contractions throughout the evaluation period and even after definitive treatment is important. A strong correlation is observed between intra-abdominal infectious or inflammatory processes and preterm labor and delivery.


Diagnostic Imaging


US is probably the imaging modality that is most frequently used for evaluating a pregnant abdomen. Extensive experience documents the safety of US in pregnancy. The maternal gallbladder, pancreas, and kidneys can be evaluated easily. Limitations are related to the body habitus in the later stages of gestation.

US is also used with graded compression as a diagnostic aid for appendicitis. The size of the gravid abdomen may limit this approach in pregnancy, but some researchers have reported success. [18, 19] In a series of 33 pregnant patients, the sensitivity of magnetic resonance imaging (MRI) for acute appendicitis was 80%, compared with 20% for US. The appendix could not be identified in 29 patients, including three with proven appendicitis. In a study using both US and MRI, Pedrosa et al found that the former had a sensitivity of 36% and that a normal appendix was identified on US in only two of 126 patients without appendicitis. [20]

In addition, the use of US is essential for fetal evaluation. US helps to establish gestational age and fetal viability, to exclude congenital anomalies, and to assess amniotic fluid volume and fetal well-being. This information may become critical later in the management of a gravid patient with an acute abdomen, when decisions regarding delivery, mode of delivery, and the use of tocolytics and steroids must be made.

Radiography and computed tomography

Whereas ionizing radiation in the evaluation of patients who are pregnant is often a source of anxiety for the practicing clinician, radiation exposure from a single diagnostic procedure does not result in harmful fetal effects. [21] (See Table 1 below.)

Table 1. Estimated Fetal Exposure From Some Common Radiologic Procedures (Open Table in a new window)


Fetal Exposure (mGy)

Chest radiography (two views)


Abdominal radiography


Intravenous pyelography


Cervical spine radiography < 0.001

Lumbar spine radiography


Mammography (two views)


Extremity radiography < 0.001

Double-contrast barium enema


Head or neck CT 0.001-0.01

Chest CT or CT pulmonary angiography


Abdominal CT


Pelvic CT 10-50

Limited CT pelvimetry (single axial section through femoral heads)

< 1

*Exposure depends on number of films. (Data from American College of Obstetricians and Gynecologists, 2017. [21] )

If multiple diagnostic procedures are needed, it should be kept in mind that exposure to less than 0.05 Gy has not been associated with an increase in fetal anomalies or pregnancy loss. Exposure greater than 200 mGy (0.2 Gy) during organogenesis, at 2-8 weeks, may induce anomalies and/or growth retardation. Severe mental retardation may occur at 8-12 weeks of development if exposure is greater than 500 mGy (0.5 Gy) and greater than 250 mGy (0.25 Gy) at 16-25 weeks of development. Absorbed fetal dose from a single abdominal and pelvic computed tomography (CT) examination is substantially below this level. [22]

During pregnancy, medically indicated diagnostic radiographic procedures should be performed when needed; when possible, however, other imaging procedures not associated with ionizing radiation should be considered instead of radiography. [21] Because of the possible association of antenatal radiation exposure with childhood cancer, [23]  ionizing radiation should be employed only when medically necessary, and exposure to such radiation should be minimized to the extent possible without compromise of patient care.

Magnetic resonance imaging

That MRI uses magnets rather than ionizing radiation to alter the energy state of hydrogen protons may be advantageous in the evaluation of the maternal abdomen and the fetus. [24] In a series, MRI was found to be useful in the diagnosis of acute appendicitis when US was inconclusive. [20, 25, 26, 27, 28, 29] MRI to date has shown high sensitivity and specificity for appendicitis. [22]  In a 2017 committee opinion, the American College of Obstetricians and Gynecologists (ACOG) stated that MRI, where readily available, is preferable to US in the diagnosis of appendicitis because of its lower nonvisualization rates. [21]

Although no adverse fetal effects have been documented, the National Radiological Protection Board advised against the use of MRI in the first trimester. [30] Clinical and laboratory studies done over a period exceeding 20 years did not document harmful effects from MRI when a magnetic field strength of 1.5T or lower was employed. [22] Not all MRI contrast agents are approved for use in pregnancy. Intravenous (IV) gadolinium crosses the placenta, and its effects on the fetus are not understood. The US Food and Drug Administration (FDA) has labeled gadolinium a category C drug. [22]

Noncontrast MRI is increasingly being performed to evaluate pregnant women with abdominal pain, either as the first-line test or as a second test following US. [31]


Surgical Considerations

Timing of surgery

Treatment of acute abdomen in pregnancy depends on the specific diagnosis. [32, 33, 34, 6, 35]

Indications for emergency surgery are the same for patients who are pregnant as for any other patients. If surgery is required but is considered elective, waiting until after the pregnancy is completed is prudent. If surgery is deemed necessary during pregnancy, it should be performed in the second trimester if possible; the risk of preterm labor and delivery is lower in the second trimester than in the third, and the risk of spontaneous loss and risks due to medications such as anesthetic agents are lower in the second trimester than in the first.

Laparoscopy during pregnancy

Laparoscopy is increasingly employed in the treatment and evaluation of acute abdomen. In the past, pregnancy was considered a contraindication for laparoscopy, but multiple reports of the successful use of diagnostic and therapeutic laparoscopy have been published. [36, 37, 38]

The Hasson technique, an open approach to entering the abdomen, has been suggested to avoid potential injury to the gravid uterus with the Veress needle or trocar. Insufflation of CO2 to a pressure of 10-15 mm Hg is considered safe. Because of the CO2 exchange in the peritoneal cavity and concerns over the effects of acidosis on the fetus, the use of capnography during laparoscopy in pregnant patients is recommended. [39]

Advantages of laparoscopy over laparotomy include shortened hospital stay, less need for narcotics, easier postoperative ambulation, and earlier postoperative tolerance of oral intake. Care must be taken to minimize manipulation of the uterus. Trocar location should be adjusted on the basis of uterine size. Fetal heart tones should be monitored during the surgical procedure. The surgeon must work closely with the obstetrician to maintain fetal well-being during the surgical procedure. An experienced laparoscopist is important to keep surgical times as short as possible. [40]

Although laparoscopy is generally accepted as safe, reports of fetal demise after the procedure have appeared in the literature. [41] Several studies have indicated, however, that laparoscopic surgery can be safely performed on pregnant patients during any trimester, without an appreciably increased risk to the mother or the fetus. [39]  In a study comparing single-port laparoendoscopic surgery with conventional multiport laparoscopy in pregnant women with acute abdomen, Jiang et al found that whereas the two approaches were comparable in terms of feasibility and efficacy, the single-port approach was associated with less postoperative pain, a shorter hospital stay, and lower anxiety. [42]


Obstetric Concerns

Preterm labor and delivery constitute the most significant threat to the fetus in the management of acute maternal intra-abdominal disease. Insufficient data are available to quantitate the risk, but the severity of the disease process appears to be a major determinant of that risk. [43, 44, 45]

The prophylactic effect of tocolytics remains unproven in these patients. If used, tocolytics should be administered with care. Monitor the patient carefully, and bear in mind the potential for pulmonary complications. Magnesium sulfate, beta-mimetics (eg, ritodrine, terbutaline), and indomethacin (if the gestational age is less than 32 weeks) can be used. Whenever using tocolytic agents, it is important to ensure that no contraindications to tocolysis, such as severe placental abruption, chorioamnionitis, or lethal anomalies, are present.

If preterm delivery is likely, glucocorticoids can be administered to the mother to decrease the risk of neonatal complications. Glucocorticoids should be avoided if the mother is at serious risk for significant infection.

Delivery decisions should be based on obstetric indications. The mode of delivery used should also be decided on the basis of obstetric indications. If continuation of the pregnancy is expected to lead to maternal morbidity or mortality, delivery is indicated. If improvement of the maternal condition cannot be expected with delivery, the patient should be treated with the fetus in utero.


Non-OB/GYN Causes: Appendicitis

Appendicitis is the most common nonobstetric cause of surgical emergency in pregnancy. The case-to-delivery ratio ranges from 1:2000 to 1:6000. [15, 46, 47, 48]  Pregnancy does not affect the overall incidence of appendicitis, but the severity may be increased in pregnancy. The incidence of perforation is 25% in pregnancy. If surgery is delayed for more than 24 hours, the incidence of perforation increases to 66%. [49] Appendicitis seems to be more common in the second trimester. [13, 3, 4]

History and physical examination

Abdominal pain is almost always present. In the first trimester, pain is located in the right lower quadrant (RLQ); in the second trimester, the appendix is located at the level of the umbilicus; and in the third trimester, pain is diffuse or in the right upper quadrant (RUQ).

Other symptoms of appendicitis include the following:

  • Nausea - Present in nearly all cases
  • Vomiting - Present in two thirds of pregnant patients
  • Anorexia - Present in only one third to two thirds of pregnant patients, though present almost universally in nonpregnant patients [13, 46, 48, 50]

The following also can be observed in appendicitis:

  • Direct abdominal tenderness - Observed most commonly and only rarely absent [13, 51]
  • Tenderness in the first trimester - Well localized in the RLQ
  • Tenderness later in pregnancy - In the right periumbilical area, in the RUQ, or else diffuse
  • Rebound tenderness - Present in 55-75% of patients [13, 46, 48, 51, 52]
  • Abdominal muscle rigidity - Observed in 50-65% of patients [46, 52, 53]
  • The Rovsing sign - Pain at the McBurney point when pressure is exerted over the descending colon; observed as frequently in pregnant persons with appendicitis as in nonpregnant persons with appendicitis
  • Psoas irritation - Observed less frequently in pregnancy than in nonpregnant states [50]
  • Rectal tenderness - Usually present, particularly in the first trimester [13]
  • Fever and tachycardia - Variably present; they are not sensitive signs


In pregnancy, the WBC count is often as high as 15,000/μL. However, the wide reference range limits the usefulness of WBC counts during pregnancy [48] ; severe disease can occur with a normal count. Polymorphonuclear leukocytes (PMNs) are often greater than 80% when appendicitis is present.

Workup for appendicitis can also include the following:

  • Urinalysis - Pyuria is observed in 10-20% of patients with appendicitis [48] ; this may represent coincident asymptomatic bacteriuria
  • US - In some centers, US has been used to help diagnose appendicitis
  • Upright abdominal radiography - In severe disease, a right-side mass or free air may be visualized
  • MRI and CT - These have been used in difficult cases


Treatment of appendicitis is surgical. Appendectomy, either open or laparoscopic, should be performed as soon as the diagnosis is seriously considered. (Laparoscopic appendectomy is the method preferred by most surgeons.) Maternal and fetal outcomes are good with surgical treatment. [54]

Even if the appendix appears normal, there are two reasons to remove it. First, early disease may be present despite the grossly normal appearance; and second, diagnostic confusion can be avoided if the condition recurs. [55, 56]

The surgical approach must be tailored to the clinical situation. The operating table should be tilted 30º to the patient's left to help bring the uterus away from the surgical site and to improve maternal venous return and cardiac output.


Perforation and abscess formation are more likely to occur in pregnant patients with appendicitis than in nonpregnant patients with appendicitis. [52] Some researchers have reported increasing severity in the third trimester, [13] whereas others have not. [48, 51] Any increase in severity later in pregnancy may be due to a delay in diagnosis. The rate of generalized peritonitis relates directly to the time elapsed from symptom onset to diagnosis. [57] Maternal and fetal morbidity and mortality increase once perforation occurs. [51]


Non-OB/GYN Causes: Acute Cholecystitis

Estimates of occurrence of acute cholecystitis vary widely. The case-to-delivery ratio ranges from 1:1130 to 1:12,890. [58, 59] Asymptomatic gallbladder disease is more common, occurring in 3-4% of pregnant women. Gallstones are present in more than 95% of patients with acute cholecystitis. Chronic hemolytic conditions, such as sickle cell disease, increase the risk for gallstone formation. [60]

History and physical examination

Patients may have a history of previous episodes. RUQ pain is the most reliable symptom; pain may radiate to the back. Vomiting occurs in approximately 50% of cases, whereas fever occurs in very few instances. [59] Direct tenderness is usually present in the RUQ; rebound tenderness is rare. Cholecystitis can mimic appendicitis in the third trimester.


Workup includes the following tests and considerations [61] :

  • US - Diagnostic and safe
  • Radionucleotide scan of the gallbladder - If needed, the radiation dose is not prohibitive
  • Blood tests - Of limited value
  • Leukocytosis - Observed in normal pregnancy
  • Serum alkaline phosphatase (ALP) levels - Normally elevated in pregnancy
  • Aspartate transferase (AST) and alanine transferase (ALT) levels - May help distinguish cholecystitis from hepatitis
  • Serum amylase levels - Elevated transiently in as many as one third of patients [62, 63] ; a markedly elevated amylase level suggests pancreatitis
  • Serum electrolyte evaluations - Needed if vomiting has been persistent

Supportive therapy

Management of symptomatic cholelithiasis is controversial. Some recommend initial nonoperative treatment, whereas others favor early surgical treatment. [49] Initial nonoperative treatment, as follows, is supportive in nature:

  • IV fluids
  • Nasogastric suction - This may be necessary if vomiting has been significant
  • Analgesia - Demerol is preferred to morphine; morphine may produce spasm of the sphincter of Oddi.
  • Antibiotics - If symptoms persist or if systemic or local signs are prominent, broad-spectrum antibiotic therapy should be initiated [62, 63]

Surgical therapy

If the patient does not tolerate supportive therapy or has recurrent bouts, surgery is indicated. [35] The timing of surgery for acute cholecystitis is controversial. Some researchers promote the performance of surgery during pregnancy in order to avoid recurrent episodes and hospitalization. [49, 64] Others promote the delaying of surgery until the postpartum period. [65] A growing body of evidence supports the safety of laparoscopic cholecystectomy during pregnancy. [49, 66, 67]

Laparoscopy can be safely performed during any trimester of pregnancy. Studies comparing conservative and surgical management of cholecystitis revealed the incidence of preterm delivery (3.5% vs 6.0%) and fetal mortality (2.2% vs 1.2%). Fetal mortality in gallstone pancreatitis was 8.0% in a conservatively treated group of patients and 2.6% in a surgically treated group, suggesting that early surgical management is preferable. [68]


Complications can occur, including empyema, perforation, pancreatitis, and failure to respond to medical management. Patients diagnosed with symptomatic cholelithiasis during the first trimester have a recurrence rate of 92%; during the second trimester, the recurrence rate is 64%, and during the third trimester, the rate is 44%. Compared with patients who undergo cholecystectomy, patients in whom surgery is delayed experience increases in hospitalization, spontaneous abortion, preterm labor, and preterm delivery. Fetal loss occurs in 10-60% of pregnant patients with gallstone pancreatitis. [39]


Non-OB/GYN Causes: Pancreatitis

Pancreatitis is an unusual and potentially devastating occurrence. The case-to-delivery ratio ranges from 1:1289 to 1:3333. [69, 70, 71, 72] The issue of whether pregnancy predisposes patients to pancreatitis is controversial. [5, 69, 71, 73, 74] Risk factors include the following:

  • Cholelithiasis - This is the most common risk factor in pregnant patients with pancreatitis, being observed in 90% of pregnancy-associated pancreatitis [70, 72, 73, 74, 75, 76]
  • Alcohol use
  • Hyperlipidemia
  • Hyperparathyroidism
  • Abdominal trauma
  • Viral infections

History and physical examination

The presentation of pancreatitis in pregnant patients is similar to that in patients who are not pregnant. Findings are as follows:

  • Acute abdominal pain - Observed in 75% of cases [70]
  • Onset - Usually sudden
  • Pain - Located in the epigastrium
  • Nausea and vomiting - Usually present and sometimes severe
  • Low-grade fever - May be present
  • Jaundice - Observed in a few patients
  • Epigastric tenderness - The most reliable physical finding
  • Peritoneal signs - Minimal or absent
  • Bowel sounds - Diminished


Serum amylase is the most useful test for diagnosis. As stated earlier, a markedly elevated amylase level suggests pancreatitis. During normal pregnancy, however, amylase levels are slightly elevated. [75, 77] Such slight elevations should be viewed with caution because they can occur with other disease entities (eg, intestinal perforation, infarction, [8]  or intestinal obstruction).

Other laboratory findings may be helpful, including the following:

  • Hyperglycemia
  • Hyperbilirubinemia
  • Hypocalcemia
  • Hemoconcentration
  • Electrolyte abnormalities

A study by Zhang et al, which compared 59 women who had acute pancreatitis in pregnancy (APIP) with 179 random normal pregnant women, found that elevated values for neutrophil-to-lymphocyte ratio, gamma-glutamyl transpeptidase (GGT), and lipase, as well as decreased values for high-density lipoprotein (HDL), were significantly associated with APIP and thus might serve as predicitive factors for this condition. [78]  

US of the upper abdomen may be helpful for confirming gallbladder disease.

Supportive therapy

Initial treatment is supportive [79] and includes the following:

  • Provision of IV fluids for hypovolemia
  • Correction of electrolyte imbalances
  • Correction of glucose levels
  • Correction of calcium disturbances
  • Withholding of oral intake
  • Continuous nasogastric suctioning - May be necessary with severe disease
  • Total parenteral nutrition (TPN) - May be needed if disease is prolonged [80]

Surgical therapy

If gallbladder disease is causative, surgery can be performed when the patient's condition stabilizes. [79]


Acute symptoms last for approximately 6 days. [74] Maternal mortality ranges from 0% to 37%, whereas perinatal mortality is approximately 11% or less. [69, 70, 72, 74, 76] The risk of perinatal death increases with the severity of disease.


Non-OB/GYN Causes: Intestinal Obstruction

The case-to-delivery ratio ranges from 1:3600 to 1:5700. [81, 82, 83] The frequency of this condition is increasing as a consequence of a higher incidence of intra-abdominal surgery. Intestinal obstruction rarely occurs during the first trimester and occurs with equal frequency in the second and third trimester and the puerperium.

Simple obstruction is the most common type of intestinal obstruction and is most likely due to prior surgery and adhesions. Volvulus is the second most common etiology and is also predominantly due to adhesions. [84, 85] Small intestinal and cecal or sigmoid volvuluses have been reported in the absence of prior adhesions. Increased mobility of the bowel and displacement of the bowel into the upper abdomen by the growing uterus are implicated in these cases. Intussusception is less common, and incarcerated inguinal or femoral hernia and carcinoma are extremely rare.


Abdominal pain is observed in 90% of patients and may be constant or periodic, mimicking labor. Pain may radiate to the flank, imitating pyelonephritis. [82] The severity of pain may not reflect the severity of disease. [86] Vomiting is a highly variable symptom. If the obstruction is more proximal, vomiting occurs earlier in the course. Severe obstruction can be present with no vomiting. [82] Constipation is different from the usual constipation in pregnancy. Patients experience a complete cessation of stool and flatus.

Physical examination

Clinical findings in pregnant patients with intestinal obstruction include the following:

  • Classic distended, tender abdomen with high-pitched bowel sounds is the exception in pregnancy
  • Abdominal tenderness may be absent [86]
  • Pressure on the uterus often causes pain due to transmitted pressure to the bowel, misleading the clinician to consider a uterine process
  • Bowel sounds are often normal on presentation
  • A tender cystic mass can sometimes be palpated [87, 88]
  • Rebound tenderness, fever, and tachycardia occur late in the course


An upright plain film of the abdomen is the best initial study. Diagnostic radiography should not be avoided out of concern for fetal effects. It is difficult to diagnose intestinal obstruction without the use of radiography. Sequential films may be needed. [86, 89]

Laboratory findings can include the following:

  • Leukocytosis - May be present; remember that leukocytosis is also observed in normal pregnancy
  • Electrolyte abnormalities
  • Hemoconcentration
  • Elevated serum amylase levels


Treatment is surgical, just as it is for patients who are not pregnant. Management of the obstruction includes the following:

  • Correction of fluid and electrolyte imbalances - Fluid management is critical during pregnancy because uterine blood flow depends on normal maternal blood volume
  • Decompression of the bowel
  • Aid in relief of the obstruction
  • Resection of nonviable tissue
  • A midline abdominal incision is optimal


Intestinal obstruction is a serious complication in pregnancy, with maternal mortality in the range of 10-20%. Perinatal mortality is in the range of 20-30%. [83, 85, 90]


Non-OB/GYN Causes: Urolithiasis

The case-to-delivery ratio for urolithiasis is approximately 1:1600. [90, 91] For patient education information, see the Pregnancy Center, as well as Ectopic Pregnancy and Blood in the Urine.

History and physical examination

Findings in urolithiasis include the following:

  • Pain, usually in the flank - Almost always the presenting complaint
  • Nausea and vomiting
  • Dysuria
  • Urgency
  • Fever
  • Gross hematuria
  • History of a prior episode - In 25% of patients [90, 91]
  • Costovertebral angle tenderness - Almost always present
  • Abdominal tenderness - Sometimes observed


Patients with urolithiasis may have coexisting urinary tract infection (UTI). In addition, microscopic hematuria is observed in 75% of cases, although the absence of hematuria does not exclude a stone. As part of the workup, strain the patient's urine to help determine whether a stone is present. US should be performed on the urinary tract to check for evidence of obstruction. The physiologic dilatation of the right side in the second half of pregnancy should be kept in mind.


Treatment depends on the size and location of the stone, the degree of obstruction, the severity of symptoms, and the presence of infection. Most stones pass with hydration. Minimally invasive procedures can be considered, including ureteral stent placement, ureteroscopic retrieval, and percutaneous nephrostomy. Extracorporeal shockwave lithotripsy has not been approved for use in pregnancy.


A good perinatal outcome is expected, unless a severe infection is present.


OB/GYN Causes: Rupture of Ovarian Cyst

Ovarian cysts occur in pregnancy with a frequency ranging from 1 in 81 to 1 in 1000. [92, 93, 94, 95] Rupture of ovarian cysts is rare.

History and physical examination

Patients may have a history of mild trauma, such as may be caused by a fall, intercourse, or a vaginal examination. However, rupture may occur spontaneously.

The patient may have mild, chronic lower abdominal discomfort that suddenly intensifies. Upon physical examination, the lower abdomen may demonstrate peritoneal signs, and tenderness and guarding may be present.


The patient's hemoglobin level may drop. US can help to detect the presence of fluid in the cul-de-sac.


Treatment is surgical. As much ovarian tissue as possible should be conserved.


In the absence of malignancy, the prognosis is excellent. [96]


OB/GYN Causes: Adnexal Torsion

Adnexal torsion is unusual and occurs predominantly in teenagers and young women. Pregnant women are predisposed to adnexal torsion, with approximately 20% of adnexal torsions occurring during pregnancy. [7, 97] The condition is associated with an ovarian mass in 50-60% of patients; the mass is most often a dermoid. Adnexal torsion occurs more frequently on the right than on the left, with a ratio of 3:2. It occurs most frequently in the first trimester, occasionally in the second, and rarely in the third. [97]

History and physical examination

Characteristics of adnexal torsion include the following:

  • Pain - Patients present with acute, severe, colicky, unilateral, lower abdominal and pelvic pain; patients may provide a history of prior intermittent episodes of similar pain
  • Nausea and vomiting - Two thirds of patients also have nausea and vomiting [98, 99]
  • Fever - A low-grade fever can occur
  • Adnexal mass - A tender adnexal mass is palpated in 90% of patients with adnexal torsion


If adnexal necrosis has occurred, leukocytosis and fever can develop. Leukocytosis is also observed in normal pregnancy.

US can be useful for documenting the presence of an ovarian cyst. Color Doppler findings may help document absent ovarian flow in the central ovarian parenchyma. [100] If the diagnosis is uncertain, diagnostic laparoscopy may be performed.

Surgical therapy

Treatment is surgical, with preservation of as much ovarian tissue as possible. [96] If the tissue is necrotic, removal is warranted and unilateral salpingo-oophorectomy is appropriate. (If a partial torsion is confirmed, conservative management is appropriate.) Treatment involves untwisting the pedicle, removing the cyst, and stabilizing the ovary. If removal of the corpus luteum is necessary prior to 10 weeks' gestation, progesterone supplementation is warranted.


Pregnancy outcome associated with adnexal torsion generally is good. [99]


OB/GYN Causes: Degenerating Myoma

Red degeneration occurs in 5-10% of pregnant women with myomas. Degenerating myoma often occurs between 12 and 20 weeks' gestation.

History and physical examination

Patients present with significant localized abdominal pain of acute onset. They may experience vomiting and tenderness over a mass in the uterus. Patients may also experience a low-grade fever. [96]


US is helpful when used directly over the area of pain. A degenerating myoma has a mixed echodense or echolucent appearance.

Pharmacologic therapy

During pregnancy, treatment is medical because red degeneration is a self-limited process. Treatment includes analgesia with narcotic or anti-inflammatory agents. If narcotics are ineffective, a short course of indomethacin can provide effective pain relief. Because indomethacin has fetal effects, including oligohydramnios and partial constriction of the fetal ductus arteriosus, its use is limited to less than 32 weeks. Patients should be monitored closely.


The pregnancy outcome associated with red degeneration usually is good.


OB/GYN Causes: Placental Abruption

The incidence of placental abruption (abruptio placentae) varies, depending on the population. Generally, abruption occurs in 1 in 150 deliveries, but the rate ranges from 1 in 75 to 1 in 225 deliveries. [101, 102] Risk increases with the following:

  • Hypertension
  • Preterm premature rupture of the membranes
  • Cocaine abuse
  • Cigarette smoking
  • Uterine myoma

History and physical examination

Symptoms of placental abruption include the following [101] :

  • Vaginal bleeding - 78%
  • Uterine tenderness and back pain - 66%
  • Uterine contractions - 22%
  • Fundal tenderness
  • High frequency of contractions or hypertonus - 34%
  • Nonreassuring fetal heart rate - 60%
  • Intrauterine fetal demise - 15%
  • In advanced cases, possible shock, evidence of disseminated intravascular coagulation (DIC), or renal failure


Evaluation of the patient includes the following:

  • Monitor the fetus for signs of distress
  • Monitor contractions for evidence of hypertonus
  • Obtain a complete blood count (CBC), coagulation profile, and type and screen
  • Perform the Kleihauer-Betke test
  • US can be performed, but it will detect, at most, only 25% of placental abruptions; MRI is superior in this setting because it yields improved soft-tissue contrast and has a wider field of view [103]


At term, delivery is treatment. The mode of delivery depends on obstetric indications. If the patient is remote from term and if the abruption is mild, conservative management can be attempted with IV fluid, tocolytics, bed rest, steroids, and continuous fetal monitoring.


Maternal morbidity depends on the presence of consumptive coagulopathy, shock, and renal failure. Perinatal mortality is in the range of 20-35%.


OB/GYN Causes: Uterine Rupture

The frequency of uterine rupture varies widely among different institutions. The case-to-delivery ratio ranges from 1:1235 to 1:3000. [17, 104, 105]

History and physical examination

Symptoms of uterine rupture include the following:

  • Severe abdominal pain
  • Chest pain from hemoperitoneum
  • Nonreassuring fetal heart rate pattern, severe bradycardia (the most common sign)
  • Loss of station of presenting part
  • Vaginal bleeding
  • Hypovolemia
  • Possible history of prior uterine surgery or uterine anomaly


Diagnosis is clinical. US may be useful if it is immediately available.


Treatment consists of immediate cesarean delivery with probable hysterectomy. Repair of the uterus may be possible in select cases. Blood products may be needed.


Maternal mortality for uterine rupture reportedly is as high as 44% in Zambia. [106] Prompt diagnosis and surgery, large amounts of blood products, and antibiotics improve maternal outcome. Fetal mortality is in the range of 50-75%. [104, 107]


OB/GYN Causes: Hepatic Rupture

The case-to-delivery ratio is 1:45,000. [108] Hepatic rupture may be spontaneous. Most such ruptures are associated with preeclampsia and eclampsia. [109] HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) is often present.

History and physical examination

Symptoms of hepatic rupture include the following:

  • RUQ pain and tenderness
  • Possible history of pregnancy-induced hypertension
  • Hemorrhagic shock
  • Distended abdomen


The diagnosis can be confirmed through CT findings.

Conservative and surgical treatment

Any associated coagulopathy should be corrected. Recombinant factor VIIa has been used to achieve hemostasis and to avert operative management. [110, 111] Most patients have been treated operatively, but there is an increasing trend toward nonoperative management (a trend that is consistent with the current principles of liver trauma management in the nonpregnant patient).

In surgery, the liver laceration should be repaired if possible, and packing should be used. Hepatic artery ligation and resection, though occasionally needed, can almost always be avoided


Maternal mortality ranges from 20% to 75%. [108]


OB/GYN Causes: Ruptured Ectopic Pregnancy

Ruptured ectopic pregnancy occurs in more than 1 in 100 pregnancies in the United States. [3]

History and physical examination

Symptoms of ruptured ectopic pregnancy include the following:

  • Abdominal or pelvic pain - The most frequent symptom, occurring in 95% of patients
  • Amenorrhea with abnormal uterine bleeding - Observed in 60-80% of patients
  • GI symptoms - Present in 80% of patients
  • Dizziness or syncope - Occurs in 58% of patients [112]
  • Hypovolemia - A possible finding
  • Pelvic mass - May be present


Workup includes a CBC, quantitative beta human chorionic gonadotropin (β-hCG) evaluation, and type and screen. If the β-hCG level is higher than 6000 mIU/mL, the gestational sac should be visible in the uterus with an abdominal probe. If the level is 1000-2000 mIU/mL, a gestational sac should be seen in the uterus with a vaginal probe. In addition to laboratory tests, US is helpful.

Surgical therapy

Treatment is surgical, with laparoscopy or laparotomy. Linear salpingotomy, linear salpingostomy, or salpingectomy can be performed. Blood products may be needed.


Maternal mortality is 3.8 cases per 10,000 population, [113] a rate that is 10 times greater than the rate for vaginal delivery and 50 times greater than the rate for induced abortion. [112]


Rare Causes

Mesenteric venous thrombosis

Mesenteric venous thrombosis is an extremely rare, but potentially lethal, event. [114] The exact incidence is not known. Most reported cases have occurred in settings in which dehydration (eg, from hyperemesis gravidarum) complicated an underlying hypercoagulable state (eg, factor V Leiden).

The treatment is resection of the involved segment with institution of chronic anticoagulation. The surgeon needs to have a low threshold for reoperation, as extension of the process to adjacent areas of the bowel is common.

Rupture of visceral artery aneurysm

Any of the visceral vessels may become aneurysmal, but splenic artery aneurysms are probably the most common and the most apt to rupture during the puerperium. Only scattered case reports are found in the literature.

The treatment is emergency splenectomy. Because of the lethality of this complication, elective aneurysm resection or angiographic coiling is recommended when these lesions are noted in women of childbearing age.