bThese include anemia, hyperthyroidism, hyperemesis gravidarum, preeclampsia, and infection. GTN = gestational trophoblastic neoplasia; hCG = human chorionic gonadotropin.
Partial moles usually have a triploid karyotype-69 ,XX, 69,Y-or much less commonly, 69,YY. These are each composed of two paternal haploid sets of chromosomes contributed by dispermy and one maternal haploid set (see Fig. 20-2B). Less frequently, a similar haploid egg may be fertilized by an unreduced diploid 46,Y sperm. These triploid zygotes result in some embryonic development, however, it ultimately is a lethal fetal condition a oergensen, 2014; Lakovschek, 2011). Fetuses that reach advanced ages have severe growth restriction, multiple congenital anomalies, or both.
Rarely, in some twin pregnancies, one chromosomally normal fetus is paired with a complete diploid molar pregnancy. Importantly, these cases must be distinguished from a single partial molar pregnancy with its associated abnormal fetus. Amniocentesis and fetal karyotyping aid confirmation.
Several unique pregnancy problems complicate such twin pregnancies. And, many women may choose to terminate the gestation, if diagnosed early. In those with continuing pregnancy, survival of the normal fetus varies and depends on associated comorbidity from the molar component. The most worrisome are preeclampsia or hemorrhage, which frequently necessitate preterm delivery. Wee and Jauniaux (2005) reviewed outcomes in 174 women, of whom 82 chose termination. Of the remaining 92 pregnancies, 42 percent either miscarried or had a perinatal death; approximately 60 percent delivered preterm; and only 40 percent delivered at term.
Another concern for those continuing their pregnancy is the risk for developing subsequent GTN. However, most data indicate no significant diference between women who continue or terminate their pregnancy (Massardier, 2009; Sebire, 2002b).
Postdelivery surveillance is conducted as for any molar pregnancy (p. 393).
The presentation of women with a molar pregnancy has changed remarkably over the past several decades because prenatal care is sought much earlier and because sonography is virtually universal. Typically, 1 to 2 months of amenorrhea precede the diagnosis. For example, in 194 women with a complete mole, evacuation was completed at a median gestational age of 9 weeks and at 12 weeks for 172 patients with a partial mole (Sun, 2015b). As a result, most molar pregnancies are detected before complications ensue (Kerkmeijer, 2009; Mangili, 2008).
As gestation advances, symptoms tend to be more pronounced with complete compared with partial moles (Niemann, 2007). Untreated molar pregnancies will almost always cause uterine bleeding that varies from spotting to profuse hemorrhage. Bleeding may presage spontaneous molar abortion, but more often, it follows an intermittent course for weeks to months. In more advanced moles with considerable concealed uterine hemorrhage, moderate iron-deiciency anemia develops. Nausea and vomiting may be signiicant. Of physical findings, many women have uterine growth that is more rapid than expected, and the enlarged uterus is comparatively softer. Fetal heart motion is absent with complete moles. he ovaries can be fuller and cystic from multiple theca-lutein cysts (Fig. 20-3). These are more common with a complete mole and likely result from ovarian overstimulation by excessive hCG levels. Because theca-lutein cysts regress following pregnancy evacuation, expectant management is preferred. Occasionally a larger cyst may undergo torsion, infarction, and hemorrhage. However,