Fetal Chromosomal Anomalies and Syndromes

trisomy

single extra chromosome (normal 46 trisomy 47)

trisomy 21 - down syndrome

most common, high hCG and inhibin A

sonographic indicators of trisomy 21

increased NT/NF, microtia, echogenic intracardiac focus, duodenal atresia, brachycephaly, hypoplastic nasal bone, pyelectasis, hyperechoic bowel, short femur and humerus

trisomy 18 - edwards syndroms

2nd most common trisomy, all lab values are decreased

sonographic indicators of trisomy 18

choroid plexus cysts, strawberry shaped head, clenched hands, single umbilical artery

trisomy 13 - patau syndrome

cannot rely on lab values

sonographic indicators of trisomy 13

holoprosencephaly, abnormal facies, ventricular dilation and brain anomalies, microcephaly, polydactyly

sonographic indicators of monsomy X

cystic hygroma, hypoplastic left heart syndrome, nonimmune hydrops, coarctation of the aorta, horseshoe kidney, ovarian dysgenesis

Triploidy

elevated hCG levels, assoc with partial molar pregnancy, theca lutein cysts, 69 chromosomes

monosomy x - turner syndrome

only affects females, cells missing on all or part of one of the x chromosomes, fatal condition leading to spontaneous abortion, all labs decreased

CHILD syndrome

congenital hemidysplasia with ichthysoiform erythroderma and limb defects, unilateral abnormalities, x-linked dominant disorder

klinefelter syndrome

47 or XXY, only occurs in males, common cause of hypogonadism, not diagnosed until adulthood

IUGR

<10th percentile for fetal weight, fundal height is clinical screening tool, oligohydramnios, doppler aids for diagnosis

symmetric IUGR

early onset of IUGR, most commonly seen with chromosomal abnormalities, associ w GI tract anomalies/maternal infections

which measurements are consistent with fetal age

cerebellum and clavicle measurement

asymmetric IUGR

late onset of IGUR, most common type, caused by placental insufficiency, AC is only part small

FL/AC ratio is most accurate for detecting

asymmetric IUGR due to "brain-sparing effect"

OB doppler

resistance is measured by evaluating the change is diastolic flow

fetal MCA doppler

detection by an increased PSV in the MCA, asymmeterical - decreased resistance = increased volume

normal flow of MCA doppler

high resistance, decreased PSV

abnormal MCA doppler

low resistance, increased PSV

uterine artery doppler

supplies the uterus and placenta, required high volume flow (low resistance)

abnormal uterine artery doppler

increased resistance/decreased EDV

increased placental resistance indicates

placental insuffiency = fetal IUGR and hypoxia

umbilical vein doppler - normal

steady, phasic with continuous flow towards the fetus, flow should always be forward and constant, ductus venosus = pulsatile waveform

abnormal ductus venosus doppler

increased fetal resistance, flow reversal, caused by CHF, hydrops, pulmonary hypoplasia

non immune hydrops

most common type, most common cause of fetal ascites and pleural effusion, at least 2 pockets of fluid, PUBS procedure

immune hydrops

Rh incompatibility, fetal anemia when maternal antibodies attack and destroy fetal RBC,

treatment of hydrops

immune treatable, fetal transfusion required and performed after PUBS, type O Rh negatitive blood delivered to umbilical vein

macrosomia

EFW >4000 grams, associated with gestational diabetes, polyhydramnios

beckwith-wiedemann syndrome

triad: macrosomia, omphalocele, macroglossia

orangomegaly, dysphagia, polyhydraminos

noonan syndrome

dwarfism, "male version of turner syndrome"

pectus excavatum

breast bone sinks into the chest

apert syndrome

craniosynostosis, syndactyly, cleft lip/palate, midface and orbital hypoplasia, fusion of the skull sutures, hands, feet

crouzon syndrome

craniosynostosis, more common and less severe than apert syndrome

pierre robin sequence

backwards displacement of the tongue (glosstoposis), U shaped palate, micrognathia and cleft palate

treacher collins syndrome

mandibulofacial dysostosis, associated with small mandible, micrognathia, holoprosencephaly, cleft palate

meckel gruber syndrome

triad: encephalocele, MDK/ARPKD, polydactyly

potter syndrome

bilateral renal agenesis, potter facies, pulmonary hypoplasia w bell shaped thorax, oligohydramnios, limb deformities, lethal

sirenomelia

fusion of the lower extremities, abn formation of feet, associated with bilateral renal agenesis

caudal regression syndrome

associated with maternal diabetes/sirenomelia

amniotic band sequence

not to be confused with uterine synechiae, amnion membrane attach to fetus

limb body wall complex

most severe form of amniotic band syndrome, severe limb and anterior body wall defects, includes two or three defects, elevated MSAFP, asso with maternal cocaine use

thoracoabdominal syndrome - PENTALOGY OF CANTRELL

cleft sternum, ectopica cordis, diaphragm defect, intracardiac anomalies, omphalocele, assoc w T13,18, Turners

VACTERL syndrome

vertebral anomalies, anal atresia, cardiac anomalies, tracheo, esophageal fistula, renal/radial ray anomalies, limb deformities (minimum 3)

fetal alcohol syndrome

assoc w IUGR, microcephaly, ASD,VSD,AVSD

holt oram syndrome

heart and hand syndrome, defects are seen in cardiac anatomy and upper extremities, defects are more severe on left side