D&C Indications (Molar Pregnancy) Case File

D&C Indications (Molar Pregnancy) Case File

Eugene C. Toy MD, Donald Briscoe, MD, FA  AFP, Bruce Britton, MD, Joel J. Heidelbaugh, MD, FA  AFP, FACG

Case 1

A 43-year-old G3P2002 woman presents to the emergency department (ED) complaining of nausea, vomiting, abdominal distention, and vaginal bleeding of 2-day duration. Her last normal LMP (last menstrual period) was 9 weeks ago. She has no known medical problems and two previously normal-term vaginal deliveries. She has not been using any contraception. On examination, she is in no acute distress. Her blood pressure (BP) is 110/90 mm Hg and heart rate (HR) 100 beats/min. The pelvic examination reveals an enlarged uterus, closed cervix, and minimal vaginal bleeding. Her serum quantitative β human chorionic gonadotropin (β-hCG) level is 120,000 mIU/mL, and a transvaginal ultrasound reveals an 18-cm uterus with a “snowstorm” pattern within the uterine cavity consistent with a hydatidiform mole.

➤ What is your management plan?

➤ What are some risk factors for the development of a hydatidiform mole?

➤ What are some differences between complete and partial hydatidiform moles?

ANSWERS TO CASE 1:

D&C Indications (Molar Pregnancy)

Summary: This is a 43-year-old G3P2002 woman at 9 weeks’ gestation by LMP, who has nausea and vomiting, and ultrasound findings consistent with a molar pregnancy.

➤ Management plan: Metastatic workup including chest radiograph, CBC, liver function tests, and then suction dilation and curettage (D&C) or possible total abdominal hysterectomy.

➤ Risk factors: History of molar pregnancy, ethnicity, maternal age.

➤ Differences between complete and partial hydatidiform moles: Complete moles are genetically composed of only paternal genetic material after a process of androgenesis. There are a total of 46 chromosomes with a complete mole (nearly always 46, XX) as compared to a partial mole which has 69 chromosomes and is derived from both maternal and paternal genotypes. Gestational trophoblastic tumors are more likely to be associated with complete moles rather than partial ones. Unlike a complete mole, partial moles may contain fetal tissue and may present similar to a missed abortion.

ANALYSIS

Objectives

1. Understand the different indications for a D&C.
2. Review the surgical technique of D&C.
3. Familiarize yourself with the differences between an obstetrical versus gynecologic D&C.

Considerations

The case described is typical of a patient with a molar pregnancy. She presents with vaginal bleeding, elevated hCG level, enlarged uterus, and ultrasound findings of “snowstorm” appearance. Her only risk factor for the development of a molar pregnancy was her age. The most important risk factor in general is history of previous molar pregnancy. Clinical symptoms of a molar pregnancy include abnormal bleeding/passage of villi, development of preeclampsia in less than 20 weeks’ gestation, hyperemesis, enlarged uterus for gestational age, abdominal pain, hyperthyroidism, and theca luteal cysts. Confirmation of a molar pregnancy is usually established with ultrasound.

One of the important goals of the gynecologist is to determine if this is an uncomplicated molar pregnancy situation or a complicated gestational trophoblastic disease. Uncomplicated molar pregnancy is treated by evacuation of the uterus or possible hysterectomy (if childbearing is completed). In contrast, gestational trophoblastic disease should be referred to the specialist, such as the gynecologic oncologist or special referral centers, if feasible. Complications include high-risk metastases (brain or liver) or high risk for choriocarcinoma. Although fertility plans were not mentioned in this case scenario, at age 43, she would be a good candidate for an abdominal hysterectomy. Approximately 80% of molar pregnancies will resolve with D&C, and the remainder develop persistent disease or other malignant features. Even though a hysterectomy does not eliminate the risk of gestational trophoblastic tumor (GTT), it reduces its risk as compared to that of D&C alone. In addition, patients older than 40 years with a molar pregnancy have at least a 33% chance of the development of GTT, making hysterectomy a good treatment option for this patient. Prior to the treatment, the patient should be assessed for some potential medical problems which may occur with molar pregnancies such as preeclampsia, anemia, hyperthyroidism, hyperemesis, and possibly pulmonary insufficiency.

After uterine evacuation, the patient should be followed closely for the development of GTT. To evaluate for the presence of possible GTT, serum β-hCG values are monitored for normal regression. Weekly β-hCG values are followed until a negative value is obtained. After the β-hCG value has reached a negative level, it may then be measured monthly for the next 6 to 12 months. Patients are usually started on some form of reliable birth control as to not become pregnant while β-hCG values are being followed. If normal regression of the β-hCG does not occur, or if the β-hCG value increases after reaching normal levels, the patient should be evaluated for the presence of GTT.1-51-5

APPROACH TO

D&C

There are numerous indications for the performance of a D&C. Table 1–1 lists both obstetrical and gynecologic indications for D&C.

With the exception of ectopic pregnancy evaluation, all other obstetrically indicated D&Cs are therapeutic in nature. Because of the risks associated with surgical management of miscarriages, numerous other management options are now available for the management of abortion and include expectant management and medical therapy. It has been reported that the overall success rate with expectant management is approximately 39%.6 The efficacy of expectant management is inversely proportional to the gestational age. Medical management success rates have been reported between 62% and 85%, depending on the agent used.7 Common medical regimens include the use of misoprostol (orally or vaginally) with or without mifepristone. American College of Obstetricians and Gynecologists (ACOG) literature states that, “Medical abortion should be considered a medically acceptable alternative to surgical abortion in selected, carefully counseled, and informed women.”8 However, patients being treated medically need to have a 24-hour availability for emergent curettage as fewer than 1% of women undergoing medical abortion will have excessive bleeding.8 When comparing all three management strategies for abortions, surgical management was most likely to induce complete evacuation of uterus and is the preferred method of management for gestations of longer than 11 weeks. The appropriate management strategy should be determined by both clinical factors and patient preference. A diagnostic D&C can be used in the evaluation of a possible ectopic pregnancy. If no chorionic villi are seen on frozen section, an ectopic pregnancy can be assumed. It has been reported that a frozen section was accurate in identifying chorionic villi 93% of the time.9,10

Gynecologic D&Cs are most often diagnostic, in other words, assessing for a disease process such as abnormal uterine bleeding or postmenopausal bleeding. However, because D&Cs are blind procedures and may miss focal areas of abnormalities, some experts recommend that a hysteroscopy be performed at the same time to evaluate the entire uterine cavity. Studies have shown that when comparing endometrial biopsy, D&C, and hysteroscopy, 17% of patients who underwent hysteroscopy had additional pathology picked up that was not detected with either blind procedure.11 Studies have also demonstrated that ultrasound and sonohysterogram are also effective in evaluating the uterine cavity.12

D&C TECHNIQUE

When performing a D&C for obstetrical indications, a suction device is often used. Suction curettage is the surgical management of choice for abortions at less than 12 weeks’ gestation or for molar pregnancies. Either local or general anesthesia may be used. The patient is then placed in dorsal lithotomy position. After a pelvic examination is performed to determine the axis of the uterus, a tenaculum or Allis clamp can be placed on the anterior lip of the cervix for traction during the D&C. A uterine sound may be used by some physicians as a means to assess uterine size and direction of cervical canal.

The cervix is then gently dilated with cervical dilators (ie, Pratt, Hank, Hegar); see Figure 1–1. Care must be taken to not “force” cervical dilation and risk perforation. During the preoperative phase, the gynecologist should determine whether dilation is anticipated to be difficult; if dilation is thought to be difficult, osmotic dilators and vaginal administration of misoprostol may be considered. After adequate cervical dilation has been achieved, the appropriate suction cannula should be inserted into the uterine cavity until the fundus is felt. Suction is only applied after reaching the fundus and with curette moving in a downward direction (Figure 1–2). Evacuation is usually complete when bubbles appear in the cannula and a gritty sensation of the cavity is felt. The appropriate cannula is usually 1 mm smaller than the weeks’ gestation (although one must be aware that the smaller the diameter of the cannula, the higher the risk of uterine perforation). After suctioning contents from uterus, some physicians use a sharp curette to confirm evacuation. Oxytocic agents are given at the discretion of the physician as studies are conflicting.

Because of the significant risk of hemorrhage and uterine perforation, a suction D&C performed for a molar pregnancy is different from that of an abortion. The procedure should be performed in a fully staffed and equipped operating room (OR) under general anesthesia. Intravenous access must be

Figure 1–1. Dilation of the cervix with care to introduce the dilator in the direction

of the endocervical canal. (Reproduced, with permission, from Schorge JO, Schaffer JI,

Halvorson LM, et al. Williams Gynecology. New York: McGraw-Hill, 2008:899.)

Figure 1–2. Suction curettage taking care not to perforate through the fundus of the uterus.

secured and blood products available. As compared to traditional D&Cs, cervical dilation should be performed gently and enough to get a 10- to 12-mm suction cannula into the uterine cavity. Uterine sounding is not recommended due to risk of inciting hemorrhage and uterine perforation. Once the cervix is dilated and suction cannula is introduced into the lower uterine segment, oxytocin is infused to help reduce blood loss. Evacuation should begin in the lower uterine segment and proceed toward the fundus carefully. Simultaneous use of an ultrasound can aid with evacuation and the prevention of uterine perforation. After contents are evacuated, a sharp curette is used to gently verify evacuation of the uterus. Oxytocic agents should then be continued following the procedure to minimize blood loss. If a hysterectomy is performed, the ovaries need not be removed unless other pathology is present. The ovarian blood supply is usually secured prior to uterine manipulation and the uterine vessels are then secured with minimal uterine manipulation. By securing the blood supply to the uterus before manipulation, the chance of molar villous transportation is diminished.13,14

As compared to obstetrical D&Cs, most gynecologic-indicated D&Cs do not require the use of a suction curette. Some practitioners choose to perform a fractional D&C (curetting the endocervical area before the uterine cavity) to better assess uterine pathology. In this setting, the cervical canal should be curetted before the cervix is dilated. Because many of the patients are being evaluated for postmenopausal bleeding, dilation of the cervix is often more difficult, and the hazards include making a false tract or perforating the cervix or uterus. Uterine contracting agents are not necessary for gynecologic D&Cs. Rare does a therapeutic D&C need to be performed for gynecologic reasons. However, a D&C is the treatment of choice in patients with acute excessive vaginal bleeding and hypovolemia.

Comprehension Questions

1.1 A 56-year-old woman with chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) presents to your clinic with postmenopausal bleeding. An endometrial biopsy (EMB) is attempted in the clinic but unsuccessful secondary to a stenotic cervix.

What is the best next step in managing this patient?

A. Wait for another episode of bleeding and, when present, take the patient to the OR for a D&C.

B. Hysteroscopy with D&C in OR.

C. Office hysteroscopy.

D. Transvaginal ultrasound.

1.2 A 48-year-old woman with vaginal bleeding and a positive pregnancy test is noted to have a molar pregnancy on sonography. A search for metastasis reveals no disease. Which of the following is the best reason for hysterectomy in this patient?

A. Lower incidence of metastasis with hysterectomy

B. Less need for chemotherapy with hysterectomy

C. Improved survival with hysterectomy

D. More cost-effective management with hysterectomy

1.3 A 54-year-old woman is taken to the OR for a fractional D&C for postmenopausal bleeding. During sounding the uterus, the fundus of the uterus is perforated. The patient’s vital signs are normal. Which of the following is the best management at this stage?

A. Abandon the procedure and observe the patient in the hospital overnight.

B. Continue the procedure as long as the vital signs are normal.

C. Continue the procedure under laparoscopic guidance.

D. Perform a hysterectomy.

1.4 Which of the following describes the appropriate technique for performing a fractional D&C?

A. The curette should be held tightly in palm.

B. Pressure with tip of curette should be applied as it is advanced to the fundus.

C. The curette should be advanced to fundus and then pressure exerted on uterine wall as it is withdrawn.

D. The cervix should be dilated before attempting the endocervical curetting.

ANSWERS

1.1 D. Although a diagnostic hysteroscopy with D&C could be considered in this patient, her significant medical conditions (COPD and CHF) place her at higher risk for intraoperative surgical complications. A less invasive way to evaluate the uterus would be a transvaginal ultrasound to evaluate the endometrial stripe. If the stripe is less than 4 mm, no further workup is needed unless the patient continues to have bleeding. Numerous studies have validated the use of the endometrial stripe and postmenopausal bleeding.11

1.2 B. Hysterectomy may be considered in the treatment of a nonmetastatic gestational trophoblastic disease in women who do not desire future fertility. The primary reason for early hysterectomy is the decreased need and shorter duration of chemotherapy needed.

1.3 C. Perforation of the uterus usually occurs at the fundus, and is usually asymptomatic. Perforation with a blunt sound typically does not injure any structures; conversely, suction D&C with perforation can lead to bowel injury. Laparoscopic guidance can allow for investigation of injuries or bleeding, and also allows for uterine curettage without fear of further damage.

1.4 C. To minimize the risk of uterine perforation, the curette should be held loosely, as with holding a pencil, with pressure on uterine wall only when curetting away from the fundus. The endocervical sample of the fractional D&C should be obtained before cervical dilation and endometrial sampling.

Clinical Pearls

See Table 1-2 for definition of level of evidence and strength of recommendation

➤ Suction D&C is the treatment of choice for molar pregnancies in patients desiring future fertility (Level A).

➤ A medically managed abortion is an acceptable alternative to surgical management (Level A).

➤ Transvaginal ultrasound is an effective screening tool for uterine pathology (Level A).

➤ The addition of hysteroscopy to a D&C increases diagnostic yield (Level A).

REFERENCES

1. Katz VL, Lentz GM, Lobo RA, Gershenson DM. Gestational trophoblastic disease and abnormal uterine bleeding. In: Comprehensive Gynecology. 5th ed. Philadelphia, PA: Mosby; 2007:889-900, 915-929. 

2. Gilstrap III LC, Cunningham FG, Vandorsten JP. Gestational trophoblastic disease. In: Operative Obstetrics. 2nd ed. New York, NY: McGraw-Hill; 2002:615-628. 

3. Goldstein DP, Berkowitz RS, Berstein MR. Reproductive performance after molar pregnancy and gestational trophoblastic tumor. Clin Obstet Gynecol. 1984;27:221. 

4. Cunningham FG, Leveno KJ, Bloom SL, Gilstrap III LC, Wenstrum KD. Abortion and gestational trophoblastic disease and abortion. In: Williams Obstetrics. 22nd ed. New York, NY: McGraw-Hill; 2005:241-247, 273-283. 

5. American College of Obstetricians and Gynecologists. Diagnosis and Treatment of Gestational Trophoblastic Disease. ACOG Practice Bulletin, 53. Washington, DC; 2004. 

6. Sotiriadis A, Makrydimas G, Papatheodorou S, Ioannidis JP. Expectant, medical, or surgical management of first trimester miscarriage: a meta-analysis. Obstet Gynecol. 2005;105:1104-1113. 

7. Chen BA, Creinin MD. Contemporary management of early pregnancy failure. Clin Obstet Gynecol. 2007;50:67-88. 

8. American College of Obstetricians and Gynecologists. Medical Management of Abortion. ACOG Practice Bulletin, 67. Washington, DC; 2005. 

9. Spandorfer SD, Menzin A, Barnhart KT, et al. Efficacy of frozen section evaluation of uterine curettings in the diagnosis of pregnancy. Am J Obstet Gynecol. 1996; 175:603. 

10. American College of Obstetricians and Gynecologists. Management of Anovulatory Bleeding. ACOG Practice Bulletin, 14. Washington, DC; 2000. 

11. Gimpelson RJ, Rappold HO. A comparative study between panoramic hysteroscopy with directed biopsies and dilation and curettage. Am J Obstet Gynecol. 1988;158:489. 

12. Goldstein SR. The role of transvaginal ultrasound or endometrial biopsy in the evaluation of the menopausal endometrium. Am J Obstet Gynecol. 2009;201:5-11. 

13. Baggish M, Karram M. Trophoblastic disease. Atlas of Pelvic Anatomy and Gynecologic Surgery. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2006:1150-1159. 

14. Rock J, Jones H. Normal and abnormal bleeding. In: Te Linde’s Operative Gynecology. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:595-605.

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