Anesthesia or surgery may precipitate thyroid storm. Thus, if hyperthyroidism is suspected before the induction of anesthesia for molar evacuation, β-adrenergic blocking agents should be administered. Thyroid storm may be manifested by hyperthermia, delirium, convulsions, tachycardia, high-output heart failure, or cardiovascular collapse. Administration of β-adrenergic blocking agents prevents or rapidly reverses many of the metabolic and cardiovascular complications of thyroid storm. After molar evacuation, thyroid function test results rapidly return to normal.
Hyperthyroidism develops almost exclusively in patients with very high hCG levels. Some investigators suggest that hCG is the thyroid stimulator in women with molar pregnancy because positive correlations between serum hCG levels and total T4 or T3 concentrations were observed. However, in one study in which thyroid function was measured in 47 patients with a complete mole, no significant correlation was found between serum hCG levels and serum values of free T4 index or free T3 index (26). Although some investigators speculated about a separate chorionic thyrotropin, this substance is not yet isolated.
Trophoblastic Embolization Respiratory distress rarely occurs in patients with a complete mole. It is usually diagnosed in patients with excessive uterine size and markedly elevated hCG levels. These patients may have chest pain, dyspnea, tachypnea, and tachycardia and may experience severe respiratory distress during and after molar evacuation. Auscultation of the chest usually reveals diffuse rales, and chest radiographic evaluation may show bilateral pulmonary infiltrates. Respiratory distress usually resolves within 72 hours with cardiopulmonary support. In some circumstances, patients may require mechanical ventilation. Respiratory insufficiency may result from trophoblastic embolization and the cardiopulmonary complications of thyroid storm, preeclampsia, and massive ﬂuid replacement.
Theca Lutein Ovarian Cysts Prominent theca lutein ovarian cysts (6 cm in diameter) develop in about one-half of patients with a complete mole (27). Theca lutein ovarian cysts result from high serum hCG levels, which cause ovarian hyperstimulation (28). Because the uterus may be excessively enlarged, theca lutein cysts can be difficult to palpate during physical examination; however, ultrasonography can accurately document their presence and size. After molar evacuation, theca lutein cysts normally regress spontaneously within 2 to 4 months.
Prominent theca lutein cysts may cause symptoms of marked pelvic pressure, and they can be decompressed by laparoscopic or ultrasonographically directed aspiration. If acute pelvic pain develops, laparoscopy should be performed to assess possible cystic torsion or rupture.
Partial Hydatidiform Mole Patients with partial hydatidiform mole usually do not have the dramatic clinical features characteristic of complete molar pregnancy. These patients have the signs and symptoms of incomplete or missed abortion, and partial mole is diagnosed after histologic review of the tissue obtained by curettage (29).
In a survey of 81 patients with a partial mole, the main initial sign was vaginal bleeding, which occurred in 59 patients (72.8%) (30). Excessive uterine enlargement and preeclampsia were present in three patients (3.7%) and two patients (2.5%), respectively. No patient had theca lutein ovarian cysts, hyperemesis, or hyperthyroidism. The initial clinical diagnosis was an incomplete or missed abortion in 74 patients (91.3%) and hydatidiform mole in five patients (6.2%). Pre-evacuation hCG levels were measured in 30 patients and were higher than 100,000 mIU/mL in two patients (6.6%).