Diagnostic ultrasound ( PDFDrive )

1474 PART IV Obstetric and Fetal Sonography
abnormalities are associated with oligohydramnios, umbilical
artery Doppler abnormalities, IUGR, central nervous system
injury, and fetal demise. Maternal loor infarction tends to recur
in subsequent pregnancies. 28,103-105 Although peripheral infarctions
are common at term, infarctions larger than 3 cm or involving
more than 5% of the placenta are associated with increased
perinatal morbidity. Both maternal and fetal thrombophilias can
lead to placental infarctions. 106
he sonographic indings of maternal loor infarction include
a hyperechoic placental mass (Fig. 43.16A) or placental thickening.
Hyperechoic areas of the placenta are especially prominent
FIG. 43.12 Placental Abruption. Transabdominal sonogram of the
placenta (PL) with a hematoma (calipers) lifting the placenta away from
the uterine wall. See also Videos 43.6 and 43.7.
PL
along the maternal surface of the placenta and can stretch into
the placental substance itself. hese can be a normal inding,
especially with mature placentas. Hyperechoic placental masses
may be associated with central hypoechoic spaces as they
organize. Subchorionic cysts are also commonly present with
maternal loor infarction (Fig. 43.16B). On this continuum are
placental basal plate calciications, which at times, can be quite
prominent (Fig. 43.16C). he hyperechoic mass seen with
maternal loor infarction resembles that seen with placental
chorioangiomas. 107
Placental infarctions caused by maternal vascular disease oten
result in uteroplacental ischemia and infarction of the villi. hese
appear as echogenic, rimmed cystic lesions within the placenta,
not necessarily at the maternal side of the placenta or basal plate
(Fig. 43.17, Videos 43.10 and 43.11). When identiied early in
gestation, anticoagulation with heparin may improve outcome;
however, further investigation is necessary before establishing
treatment guidelines. 108,109
PLACENTAL MASSES
Solid-appearing placental masses include chorioangioma,
subamniotic hematoma, subchorionic hematoma, and placental
hemorrhage. hese masses should be diferentiated from luidilled
placental regions of placental cysts and venous lakes. As
previously discussed, placental infarctions may also have a
masslike appearance.
Subchorionic placental cysts on the fetal surface of the
placenta are predominantly innocuous indings on prenatal
sonography, similar to cysts in the substance of the placenta
(Fig. 43.18). Most fetuses whose placentas contain these cysts
have normal outcomes. Larger cysts (>4.5 cm) are associated
with IUGR. Maternal loor infarction may also be associated
with placental cysts. 110,111
A
B
FIG. 43.13 Subchorionic Hematoma. (A) Transabdominal transverse view of the uterus in the second trimester shows acute subchorionic
hematoma (calipers). The anterior placenta is shown by the short arrow. (B) Transabdominal midsagittal view of the same patient later in pregnancy
demonstrates the subchorionic hematoma (long arrow) more hypoechoic and located overlying the cervix (calipers); short arrow, placenta.