Abdominal Pain in Pregnancy (Ovarian Torsion) Case File

Abdominal Pain in Pregnancy (Ovarian Torsion) Case File

Eugene C. Toy, MD, Patti Jayne Ross, MD, Benton Baker III, MD, John C. Jennings, MD

CASE 13

A 23-year-old G2P1 woman at 16 weeks’ gestation complains of a 12-hour history of colicky, right lower abdominal pain, and nausea with vomiting. She denies vaginal bleeding or leakage of fluid per vagina. She denies diarrhea or eating stale foods. She has a history of an 8-cm ovarian cyst, and otherwise has been in good health. She denies dysuria or fever, and has had no surgeries. Her vital signs include a blood pressure (BP) of 100/70 mm Hg, heart rate (HR) of 105 beats per minute (bpm), respiratory rate (RR) of 12 breaths per minute, and temperature of 99°F (37.2°C). On abdominal examination, her bowel sounds are hypoactive. The abdomen is tender in the right lower quadrant region with significant involuntary guarding. The cervix is closed. The fetal heart tones are in the range of 140 bpm.

» What is the most likely diagnosis?

» What is the best treatment for this condition?

ANSWER TO CASE 13:

Abdominal Pain in Pregnancy (Ovarian Torsion)                          

Summary: A 23-year-old G2P1 woman at 16 weeks’ gestation with an 8-cm ovarian cyst complains of a 12-hour history of colicky, right lower abdominal pain, and nausea with vomiting. The abdomen is tender in the right lower quadrant region with significant involuntary guarding.

• Most likely diagnosis: Torsion of the ovary.
• Best treatment for this condition: Surgery (laparotomy due to the pregnancy).

ANALYSIS

Objectives

1. Know the clinical presentation of some of the common causes of abdominal pain in pregnancy (acute appendicitis, acute cholecystitis, ovarian torsion, placental abruption, and ectopic pregnancy).
2. Understand that surgery is the best treatment for ovarian torsion.
3. Know that oophorectomy does not necessarily need to be performed in ovarian torsion.

Considerations

This woman, who is pregnant at 16 weeks’ gestation, has a history of an 8-cm ovarian cyst. The ovarian mass is most likely a dermoid cyst because of her young age. The acute onset of colicky, lower abdominal pain, and nausea with vomiting are consistent with ovarian torsion, which is the twisting of the ovarian vessels leading to ischemia. Gastrointestinal complaints are common. She does not have a history of abdominal surgeries and the abdomen is not markedly distended, making bowel obstruction less likely. The treatment for ovarian torsion is surgical. Because her gestational age is 16 weeks, laparoscopy is an option. Sometimes, the size of the mass makes exploratory laparotomy the best choice. Upon opening the abdomen, the surgeon would examine the ovary for viability. Sometimes, untwisting of the ovarian pedicle can lead to reperfusion of the ovary. An ovarian cystectomy, that is, removing only the cyst and leaving the remainder of the normal ovarian tissue intact, is the best treatment. This patient is somewhat atypical regarding the gestational age, since the majority of pregnant women with ovarian torsion present either at 14 weeks’ gestation when the uterus rises above the pelvic brim, or immediately postpartum when the uterus rapidly involutes.

APPROACH TO:

Abdominal Pain in Pregnancy                                                  

CLINICAL APPROACH

Diseases related to and unrelated to the pregnancy must be considered. Additionally, the pregnancy state may alter the risk factors for the different causes of abdominal pain, and change the presentation and symptoms. Common causes of abdominal pain in pregnant women include appendicitis, acute cholecystitis, ovarian torsion, placental abruption, and ectopic pregnancy. Less common is carneous or red degeneration of a uterine fibroid, caused by the rapid growth due to high estrogen levels. Affected patients will complain of point tenderness at the uterine fibroid, confirmed on ultrasound. Often, it is difficult to differentiate from among these different etiologies, but a careful history and physical and re-examination are the most important steps (Table 13– 1).

Table 13–1 • DIFFERENTIAL DIAGNOSIS OF ABDOMINAL PAIN IN PREGNANCY
	Time during Pregnancy	Location	Associated Symptoms	Treatment
Appendicitis	Any trimester	Right lower quadrant →right flank or right upper quadrant	Nausea and vomiting Anorexia Leukocytosis Fever	Surgical
Cholecystitis	After first trimester	Right upper quadrant	Nausea and vomiting Anorexia Leukocytosis Fever	Surgical
Torsion	More commonly at 14 weeks’ gestation or after delivery	Unilateral, abdominal, or pelvic	Nausea and vomiting; colicky pain	Surgical
Pancreatitis	Any trimester	Epigastric pain radiating to the back	Constant, boring pain, nausea and vomiting	Nothing by mouth, ERCP if common bile duct stone suspected
Placental abruption	Second and third trimesters	Midline persistent uterine	Vaginal bleeding Abnormal fetal heart tracings	Delivery
Ectopic pregnancy	First trimester	Pelvic or abdominal pain, usually unilateral	Nausea and vomiting Syncope Spotting	Surgical or medical
Ruptured corpus luteum	First trimester	Lower abdomen, sometimes unilateral	Acute onset of sharp pain, sometimes associated with syncope	Observation if selflimited; sometimes requires surgery if persistent bleeding

Acute Appendicitis

The diagnosis of appendicitis can be difficult to make because many of the presenting symptoms are common complaints in pregnancy. Furthermore, a delay in diagnosis (especially in the third trimester) frequently leads to maternal morbidity and perinatal problems, such as preterm labor and abortion. Patients typically present with nausea, emesis, fever, and anorexia. The location of the abdominal pain is not typically in the right lower quadrant (as is classic for nonpregnant patients), but instead is superior and lateral to the McBurney point. This is due to the effect of the enlarged uterus pushing on the appendix to move it upward and outward toward the flank, at times mimicking pyelonephritis. Diagnosis is made clinically, and because of the morbidity involved in a missed diagnosis, it is generally better to err on the side of overdiagnosing than underdiagnosing this disease. When appendicitis is suspected, the treatment is surgical regardless of gestational age, along with intravenous antibiotics.

Acute Cholecystitis

A common physiologic effect of pregnancy is an increase in gallbladder volume and biliary sludge (especially after the first trimester). The biliary sludge then serves as a precursor to gallstones. While gallstones are often asymptomatic, the most common symptoms are right upper quadrant pain following a meal, nausea, a “bloated sensation,” and, possibly, emesis. In the absence of infection or fever, this is called biliary colic. Less commonly, when obstruction of the cystic or common bile duct occurs, the pain may be severe and unrelenting, and the patient may become icteric. When fever and leukocytosis are present, the patient with gallstones likely has cholecystitis. Other complications of gallstones include pancreatitis and ascending cholangitis, a serious life-threatening infection. The diagnosis of cholelithiasis is often established by an abdominal ultrasound revealing gallstones and dilation and thickening of the gallbladder wall. Simple biliary colic in pregnancy is usually treated with a low-fat diet and observed until postpartum. However, in the face of cholecystitis, biliary obstruction, or pancreatitis in pregnancy, surgery is the treatment of choice; generally, supportive medical management is used initially during the acute phase.

Ovarian Torsion

Patients with known or newly diagnosed large ovarian masses are at risk for ovarian torsion. Ovarian torsion is the most frequent and serious complication of a benign ovarian cyst. Pregnancy is a risk factor, especially around 14 weeks and after delivery. Symptoms include unilateral abdominal and pelvic colicky pain associated with nausea and vomiting. The acute onset of colicky pain is typical. Treatment is surgical with ovarian conservation if possible. If untwisting the adnexa results in reperfusion, an ovarian cystectomy may be performed. However, if perfusion cannot be restored, oophorectomy is indicated.

Placental Abruption

Abruption is a common cause of third-trimester bleeding and is usually associated with abdominal pain. Risk factors include a history of previous abruption, hypertensive disease in pregnancy, trauma, cocaine use, smoking, or preterm premature rupture of membranes. Patients typically present with vaginal bleeding with  persistent crampy midline uterine tenderness and at times abnormal fetal heart tracings. Diagnosis is made clinically and ultrasound is not very reliable. The treatment is generally delivery, often by cesarean.

Ectopic Pregnancy

The leading cause of maternal mortality in the first and second trimesters is ectopic pregnancy. Patients usually have amenorrhea with some vaginal spotting and lower abdominal and pelvic pain. The pain is typically sharp and tearing and may be associated with nausea and vomiting. Physical findings include a slightly enlarged uterus and perhaps a palpable adnexal mass. In the case of ectopic ruptures, the patient may experience syncope or hypovolemia. Transvaginal sonography and serum human chorionic gonadotropin (hCG) levels can help with the diagnosis of ectopic pregnancy in >90% of cases. Treatment options include surgery (especially with hemodynamically unstable patients) and, in appropriately selected patients, methotrexate.

Ruptured Corpus Luteum

Corpus luteum cysts develop from mature Graafian follicles and are associated with normal endocrine function or prolonged secretion of progesterone. They are usually <3 cm in diameter. There can be intrafollicular bleeding because of thinwalled capillaries that invade the granulosa cells from the theca interna. When the hemorrhage is excessive, the cyst can enlarge and there is an increased risk of rupture. Cysts tend to rupture more during pregnancy, probably due to the increased incidence and friability of corpus lutea in pregnancy. Anticoagulation therapy also predisposes to cyst rupture, and these women should receive medication to prevent ovulation. Patients with hemorrhagic corpus lutea usually present with the sudden onset of severe lower abdominal pain. This presentation is especially common in women with a hemoperitoneum. Some women will complain of unilateral cramping and lower abdominal pain for 1 to 2 weeks before overt rupture. Corpus luteum cysts rupture more commonly between days 20 and 26 of the menstrual cycle.

The differential diagnosis of a suspected hemorrhagic corpus luteum should include ectopic pregnancy, ruptured endometrioma, adnexal torsion, appendicitis, and splenic injury or rupture. Ultrasound examination may show free intraperitoneal fluid, and perhaps fluid around an ovary. The diagnosis is confirmed by laparoscopy. The first step in the treatment of a ruptured corpus luteal cyst is to secure hemostasis. Once the bleeding stops, no further therapy is required; if the bleeding continues, however, a cystectomy should be performed with preservation of the remaining normal portion of ovary.

Progesterone is largely produced by the corpus luteum until about 10 weeks’ gestation. Until approximately the seventh week, the pregnancy is dependent on the progesterone secreted by the corpus luteum. Human chorionic gonadotropin serves to maintain the luteal function until placental steroidogenesis is established. There is shared function between the placenta and corpus luteum from the seventh to tenth week; after 10 weeks, the placenta emerges as the major source of progesterone. Therefore, if the corpus luteum is removed surgically prior to 10 to 12 weeks’ gestation, exogenous progesterone is needed to sustain the pregnancy. If the corpus luteum is excised after 10 to 12 weeks’ gestation, no supplemental progesterone is required.

CASE CORRELATION See also Case 11 (Placental Abruption), which typically presents as painful vaginal bleeding in the third trimester. Less commonly, a concealed abruption may not present with visible bleeding.

COMPREHENSION QUESTIONS

13.1 A 28-year-old G1P0 woman at 28 weeks’ gestation presents to the hospital with fever, nausea and vomiting, and anorexia of 2 days’ duration. On examination, her temperature is 100.7°F (38.16°C), HR is 104 bpm, and BP is 100/ 60 mm Hg. Her abdomen reveals tenderness on the right lateral aspect at the level of the umbilicus. There is mild right flank tenderness. A urinalysis is normal. In consideration of the diagnostic possibilities, which of the following is most accurate regarding this patient?

A. Appendicitis should be considered since the appendix location changes during pregnancy.

B. Cholecystitis is best diagnosed by CT scan of the abdomen.

C. Pyelonephritis commonly presents with normal urinalysis findings.

D. Inflammatory bowel disease should strongly be considered in this patient.

13.2 Upon performing laparoscopy for a suspected ovarian torsion on an 18-yearold nulliparous woman, the surgeon sees that the ovarian vascular pedicle has twisted 1 to 1.5 times and that the ovary appears somewhat bluish. Which of the following is the best management at this point?

A. Oophorectomy with excision close to the ovary

B. Oophorectomy with excision of the vascular pedicle to prevent possible embolization of the thrombosis

C. Unwind the vascular pedicle to assess the viability of the ovary

D. Bilateral salpingo-oophorectomy

E. Intravenous heparin therapy

13.3 A 32-year-old G1P0 woman at 29 weeks’ gestation presents with a 1-day history of severe midepigastric abdominal pain radiating to the back, and multiple episodes of nausea and vomiting. On examination, her BP is 100/ 60 mm Hg, HR is 110 bpm, and temperature is 99°F (36.6°C). Her abdominal examination has tenderness and diffuse rebound. The serum amylase level is markedly elevated. Which of the following is the next step?

A. Initiate a high-protein, low-fat diet

B. Immediate surgical excision of the inflamed aspect of the pancreas

C. Ultrasound imaging of the abdomen

D. Delivery of the infant

13.4 An 18-year-old G1P0 woman complains of a 2-month history of colicky, right abdominal pain when she eats. It is associated with nausea and emesis. She states that the pain radiates to her right shoulder. The patient has a family history of diabetes. Which of the following is the most likely diagnosis?

A. Peptic ulcer disease

B. Cholelithiasis

C. Appendicitis

D. Ovarian torsion

13.5 A 19-year-old G1P0 woman at 28 weeks’ gestation arrives to the obstetric (OB) triage area complaining of a 12-hour history of abdominal pain. She denies trauma, vaginal bleeding, or fever. On examination, her temperature is 99°F (37.2°C), HR is 100 bpm, and BP is 100/ 70 mm Hg. Her abdominal examination reveals hypoactive bowel sounds, diffuse abdominal pain with guarding. Which of the following statements regarding the abdominal pain is most accurate?

A. The absence of vaginal bleeding rules out abruption as an etiology.

B. Ovarian torsion is typically characterized by constant pain.

C. The gallbladder typically moves superior and laterally with pregnancy.

D. Degenerating leiomyoma typically presents with localized tenderness over the fibroid.

13.6 A 20-year-old G1P0 woman at 12 weeks’ gestation is noted to have a suspected ruptured ectopic pregnancy. On sonography, there is a moderate amount of free fluid in the abdominal cavity. The medical student assigned to evaluate the patient is amazed by the apparent stability of the patient. Which of the following is the earliest indicator of hypovolemia?

A. Tachycardia

B. Hypotension

C. Positive tilt

D. Lethargy and confusion

E. Decreased urine output

ANSWERS

13.1 A. The growing uterus pushes the appendix superior and lateral. The diagnosis of appendicitis during pregnancy can be difficult since patients frequently present with symptoms common in pregnancy. A delay in diagnosis, on the other hand, can lead to maternal morbidity and perinatal problems. Typically, patients present with nausea, emesis, fever, and anorexia. Abdominal pain is not located in the right lower quadrant as in nonpregnant patients because the growing uterus pushes on the appendix in an upward and outward direction, toward the flank and sometimes mimicking pyelonephritis. Regardless of gestational age, the treatment is surgical with intravenous (IV) antibiotics. Cholecystitis is also common in pregnancy, but usually presents with right abdominal pain in the subcostal region and may radiate to the right shoulder. Gallstones are best diagnosed with ultrasound rather than computed tomography (CT) scan. Pyelonephritis almost always is associated with pyuria (white blood cell [WBC] in urine), and usually causes fever and flank tenderness. Inflammatory bowel disease presents in young patients with bloody diarrhea and abdominal pain. This patient does not have diarrhea or loose stools.

13.2 C. Unless the ovary appears necrotic, the ovarian pedicle can be untwisted and the ovary observed for viability. An oophorectomy would not be indicated in this patient unless the ovaries were necrotic from the prolonged lack of perfusion, or if after untwisting the ovary, reperfusion cannot be established. It is important to try and conserve the ovary—especially in such a young patient. Previously, it was thought that a torsioned ovarian vasculature with thrombus needed excision due to the possibility of embolization. This has been disproved and neither excision of the clotted vessels or heparin is required.

13.3 C. With the diagnosis of pancreatitis, the next diagnostic steps include assessing the severity of the condition (such as with Ranson criteria of hypoxia, hemorrhagic complications, renal insufficiency, etc), and looking for an underlying etiology for the pancreatitis. In pregnancy, the most common cause of pancreatitis is gallstones, although alcohol use, hyperlipidemia, and medications are sometimes implicated. Thus, the best next step is ultrasound to assess for gallstones. If gallstones are found, then consideration may be given to eventual cholecystectomy once the patient is stabilized. Endoscopic retrograde cholangiopancreatography (ERCP) with endoscopic stone extraction can be performed if a common bile duct stone is suspected. A patient with pancreatitis should have nothing by mouth. Surgery on the inflamed pancreas is harmful. Delivery of the pregnancy is not indicated.

13.4 B. This patient has a classic presentation of symptomatic cholelithiasis (biliary colic). In pregnancy, this condition is usually treated with a low-fat diet and observed until postpartum. However, if the patient were to develop cholecystitis (gallstones with fever and leukocytosis), biliary obstruction, or pancreatitis in pregnancy, surgery is the treatment of choice; generally, supportive medical management is used initially during the acute phase.

13.5 D. Fibroids of the uterus can be associated with red or carneous degeneration during pregnancy due to the estrogen levels leading to rapid growth of the fibroid. The fibroid outgrows its blood supply leading to ischemia and pain. Typically, the pain of a degenerating fibroid is localized over the leiomyoma. Abruption can be concealed with bleeding behind the placenta. The gallbladder usually does not move during pregnancy, whereas the appendix will move superiorly and laterally. Ovarian torsion is associated with colicky abdominal pain and comes and goes.

13.6 E. Renal blood flow is decreased with early hypovolemia as reflected by decreased urine output. This is a compensatory mechanism to make blood volume available to the body. Typically before tachycardia or hypotension occurs, a positive tilt test is noted. By the time hypotension is noted at rest in a young, healthy patient, 30% of blood volume is lost.

    CLINICAL PEARLS    

» In pregnancy, the appendix moves superiorly and laterally from the normal location. » The acute onset of colicky abdominal pain is typical of ovarian torsion. » With ovarian torsion, the clinician can untwist the pedicle and observe the ovary for viability. » Ectopic pregnancy should be suspected in any woman with abdominal pain. » The most common cause of hemoperitoneum in early pregnancy is ectopic pregnancy. » A ruptured corpus luteum can mimic an ectopic pregnancy.  » Hemorrhagic corpus lutea can occur more commonly in patients with bleeding tendencies either congenital (von Willebrand) or iatrogenic (Coumadin induced). » When the corpus luteum is excised in a pregnancy of less than 10 to 12 weeks gestation, progesterone should be supplemented.

REFERENCES

Castro LC, Ognyemi D. Common medical and surgical conditions complicating pregnancy. In: H acker NF, Gambone JC, Hobel CJ, eds. Essentials of Obstetrics and Gynecology. 5th ed. Philadelphia, PA: Saunders; 2009:191-218. Katz VL. Benign gynecologic lesions. In: 

Katz VL, Lentz GM, Lobo RA, Gersenson DM, eds. Comprehensive Gynecology. 5th ed. St. Louis, MO: Mosby-Year Book; 2007:419-470.

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