Anemia of Prematurity - Portal Neonatal

o Karyotyping is always indicated if history or ultrasound results reveal a constellation of
findings consistent with a chromosomal aberration or if maternal or family history is
suggestive.
� Chromosome studies are indicated whenever initial diagnostic studies have failed to
identify with certainty a specific cause for the fetal hydrops.
� Chromosomal analyses may be performed on desquamated fetal epithelial cells in AF,
fetal tissue biopsy samples, or placental (fetal tissue) biopsy samples.
� An increase in AFP has been observed in almost 1 in 10 (8.4%) genetic
amniocenteses; fetal mortality exceeded 1 in 10 (14%) when such AFP elevations
occurred. Evidence of fetomaternal bleeding is present in 3 of 4 chorionic villous
samplings. Thus, careful weighing of benefit versus risk must be made whenever
direct invasive diagnostic methods are considered.
o To obtain more precise information concerning fetal status, direct fetal sampling by
cordocentesis (or periumbilical sampling) has been used with increasing frequency.
� Acidemia, hypoxemia, and hypercarbia are found in most studies of fetal acid-base
balance and blood-gas status obtained at time of direct fetal treatment. These results
are nonspecific and anticipated and, while they may be of use in immediate
management, are unlikely to be of value in longer-term care of the fetus with hydrops.
� Analyses of serous effusion fluids (pleural, pericardial, or ascitic, most commonly)
have been of surprisingly little value. For example, lymphocyte counts considered
characteristic of congenital chylothorax when found in the newborn infant have been
observed in pleural effusions from fetuses with CMV disease.
� Serologic tests for specific infections, hemoglobin or hematocrit measurements,
platelet counts, white cell counts and morphologic analyses, specific enzyme
analyses, and karyotyping are just a few of the more common measurements
obtained. While this information may be invaluable in specific cases, use of such
invasive methods on a routine basis carries significant risks.
� Fetal sampling by cordocentesis is followed by significant bradycardia in almost 1 in
20 samplings (3.8%); of those with such complications, almost two thirds die (61.5%).
o Elevated AF alkaline phosphatase has been observed in association with fetal hydrops
due to Turner syndrome; while likely to be a nonspecific finding, further study is
necessary.
• The fetal biophysic profile has been demonstrated to be abnormal in severe fetal hydrops.
o Cardiotocographic records obtained 12 hours prior to fetal death demonstrate absence of
short-term and long-term variability, absence of tachycardia, presence of late
decelerations, and terminal bradycardia.
o Sinusoidal heart-rate patterns have been observed consistently in hydrops associated with
severe fetal anemia related to isoimmunization and fetomaternal hemorrhage.
Imaging Studies:
• Once the possibility of fetal hydrops is considered or suspected, sophisticated and complete
fetal imaging studies are an initial absolute necessity. Hydrops is defined by the presence of
serous effusion(s) in a fetus with subcutaneous tissue edema. Some authors have
distinguished the presence of a single effusion (pleural, peritoneal) as an entity distinct from
hydrops; however, recent evidence suggests that an isolated effusion often (if not usually)
progresses to overt fetal hydrops. Exceptions appear to be isolated chyloperitoneum/ascites
(usually associated with obstructive uropathy and, thus, not true hydrops) and pleural or
peritoneal effusions that regress spontaneously (see Treatment). Thus, careful and complete
imaging is required to establish the diagnosis and the extent of the hydrops.
• Equipment employed must be capable of providing high-resolution images at large depth.
o Linear array transducers are commonly used; however, sector scanners provide better
views of the heart and many other structures.
o Range-gated Doppler capability is optimal for functional physiologic assessments. Use
of high-frequency transvaginal 2-dimensional and pulsed-wave/color Doppler flow
mapping particularly has been promising.
• The initial imaging study may provide important clues concerning the origin of the fetal