In pregnancies before 10 weeks, classic molar changes may not be apparent because villi may not be enlarged and molar stroma may not yet be edematous and avascular. Histopathologic evaluation can be enhanced by immunohistochemical staining for pS7 expression and by molecular genotyping (Banet, 2014). pS7IP2 is a nuclear protein whose gene is paternally imprinted and maternally expressed. his means that the gene product is produced only in tissues containing a maternal allele. Because complete moles contain only paternal genes, the pS7IP2 protein is absent in complete moles, and tissues do not pick up this stain (Merchant, 200S). In contrast, this nuclear protein is strongly expressed in normal placentas, in spontaneous pregnancy losses with hydropic degeneration, and in partial hydatidiform moles (Castrillon, 2001). Accordingly, immunostaining for pS7IP2 is an efective means to isolate complete mole from the diagnostic list. For distinction of a partial mole from a non molar hydropic abortus, both of which express pS7, molecular genotyping can be used. Molecular genotyping determines the parental source of alleles. Thereby, it can distinguish among a diploid diandric genome (complete mole), a triploid diandric-monogynic genome (partial mole), or biparental diploidy (nonmolar abortus).
Maternal deaths from molar pregnancies are rare because of early diagnosis, timely evacuation, and vigilant postevacuation surveillance for GTN. Preoperative evaluation attempts to identiy known potential complications such as preeclampsia, hyperthyroidism, anemia, electrolyte depletions from hyperemesis, and metastatic disease (Table 20-2) (Lurain, 2010). Most recommend chest radiography, whereas computed tomography (CT) and magnetic resonance (MR) imaging are not routinely done unless a chest radiograph shows lung lesions or unless other extrauterine disease is suspected.
Regardless of uterine size, molar evacuation by suction curettage is usually the preferred treatment. Preoperative cervical dilatation with an osmotic dilator is recommended if the cervix is minimally dilated. Intraoperative bleeding can be greater with molar pregnancy than with a comparably sized uterus containing nonmolar products. hus with large moles, adequate anesthesia, suicient intravenous access, and blood-banking support is imperative. he cervix is mechanically dilated to preferably allow insertion of a larger suction curette. Depending on uterine size, a 10-to 14-mm diameter is typical. As evacuation is begun, oxytocin is infused to limit bleeding. Intraoperative sonography is often recommended to help ensure complete uterine cavity emptying. When the myometrium has contracted, a thorough but gentle curettage with a sharp large-loop
TABLE 20-2. Some Considerations for Management of Hydatidiform Mole
Hemogram; serum 3-hCG, creatinine, electrolyte, and hepatic aminotransferase levels
TSH, free T4 levels
Oxytocin (Pitocin): 20 units in 1000 mL Ringer lactate for continuous infusion One or more other uterotonic agents may be added as needed:
Methylergonovine (Methergine): 0.2 mg = 1 mL = 1 ampule 1M every 2 hr prn
Carboprost tromethamine (PGF20) (Hemabate)k 250 .Lg = 1 mL = 1 ampule 1M every 15-90 min prn
Misoprostol (PGE1) (Cytotec): 200 mg tablets for rectal administration, 800-1000 mg once Karman cannula-size 10 or 14 mm Consider sonography machine