he median time for such resolution is 7 weeks for partial moles and 9 weeks for complete moles. Once 3-hCG is undetectable, this is confirmed with monthly determinations for another 6 months (Lurain, 2010; Sebire, 2007). Concur rently, reliable contraception is imperative to avoid confusion caused by rising 3-hCG levels from a new pregnancy. Most recommend combination hormonal contraception, injectable depot medroxyprogesterone acetate, or progestin implant (Dantas, 2017). he latter two are particularly useful if poor patient compliance is anticipated. Intrauterine devices are not used until 3-hCG levels are undetectable because of the risk of uterine perforation if there is an invasive mole. lthough not recommended, if a woman conceives during surveillance, live birth rates and risk for congenital anomalies appear to mirror the general population (Tuncer, 1999a,b). Mter these 6 months, monitoring is discontinued and pregnancy allowed.
Importantly, during 3-hCG level surveillance, either increasing or persistently plateaued levels mandate evaluation for trophoblastic neoplasia. If the woman has not become pregnant, then these levels signiY increasing trophoblastic proliferation that is most likely malignant. Several factors predispose a patient to trophoblastic neoplasia following molar evacuation. Most important, complete moles have a 15 to 20 percent incidence of malignant sequelae, compared with 1 to 5 percent following partial moles. Surprisingly, with much earlier recognition and evacuation of molar pregnancies, the risk for neoplasia has not been lowered (Schorge, 2000; Sun, 2015a). Other risk factors are older maternal age, 3-hCG levelsi> 100,000 mIU/mL, uterine size that is large for gestational age, theca-lutein cysts >6 cm, and slow decline in 3-hCG levels (Berkowitz, 2009; Kang, 2012; Wolfberg, 2005).
This group includes invasive mole, choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor. These tumors almost always develop with or after some form of recognized pregnancy. Half follow hydatidiform mole, a fourth follow miscarriage or tubal pregnancy, and another fourth develop after a preterm or term pregnancy (Goldstein, 2012). Although these four tumor types are histologically distinct, they are usually diagnosed solely by persistently elevated serum 3-hCG levels because tissue is infrequently available for study. Criteria to diagnose postmolar GTN are shown in Table 20-3.
hese placental tumors are characterized clinically by their aggressive invasion into the myometrium and propensity to metastasize. he most common inding with GTN is irregular bleeding associated with uterine subinvolution. The bleeding may be continuous or intermittent, with sudden and sometimes massive hemorrhage. Myometrial perforation from trophoblastic growth may cause intraperitoneal hemorrhage. In some women, lower genital tract metastases are evident, whereas in others only distant metastases are found with no trace of uterine tumor.
• Diagnosis, Staging, and Prognostic Scoring
Consideration for the possibility of GTN is the most important factor in its recognition. Unusually persistent bleeding ater any type of pregnancy should prompt measurement of serum 3-hCG
TABLE 20-3. Criteria for Diagnosis of Gestational Trophoblastic Neoplasia 1.
Plateau of serum �-hCG level (± 10 percent) for four measurements during a period of 3 weeks or longer-days 1, 7, 14,s21 2.