Prenatal dx A 36-year-old - PowerPoint Presentation

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Prenatal dx A 36-year-old - PPT Presentation

primigravida at 20 weeks gestation presents to her obstetricians office with a complaint of leaking fluid Sonographic examination performed confirms markedly decreased fluid and ID: 914104

syndrome risk fetal increased risk syndrome increased fetal trimester percent maternal decreased screening approximately serum sonographic mom afp pregnancy

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Slide1

Slide2

Prenatal dx

A 36-year-old

primigravida

at 20 weeks’

gestation presents

to her obstetrician’s office with a

complaint of

leaking fluid.

Sonographic

examination

performed confirms

markedly decreased fluid, and

midtrimester

rupture

of membranes is suspected. The

patient elects

to continue her pregnancy, and

minimal

amnionic

fluid is present around the fetus. At

term,her

fetus is born with a right-sided clubbed

foot.This

is an example of which of the following?

Sequence

Disruption

Deformation

Malformation

deformation-

by which a fetus develops abnormally

becauseof

extrinsic mechanical forces imposed by the uterine

envi-ronment

Slide3

deformation-

by which a fetus develops abnormally

because of

extrinsic mechanical forces imposed by the uterine

envi-ronment

Slide4

The finding seen below was identified

prenatally during

sonographic

examination and is an

example of

which of the following

Syndrome

b. Disruptionc. Associationd. Malformation

disruption, which is a more severe change in form or

function that

occurs when genetically normal tissue is modified as

theresult

of a specific insult

Slide5

disruption

, which is a more severe change in form or function that occurs when genetically normal tissue is modified as

theresult

of a specific insult

Slide6

The infant shown below was also born with a

cleft palate

. These findings are consistent with which

of the

following processes

Syndrome

Sequencec. Associationd. Chromosome abnormality A sequence describes anomalies that all developed sequentially from one initial insult.An example is the Pierre-Robin sequence in which

micrognathia

Slide7

sequence describes

anomalies

that all developed sequentially from one initial

insult.An

example is the Pierre-Robin sequence in which

micrognathia

Slide8

A pregnant 25-year-old postdoctoral student

presents for

genetic counseling following a multiple

markerscreen

that revealed an increased risk for an

openneural

-tube

defect and trisomy 18. She is

fromFrance and her husband s from Great Britain. Hermedical history is significant for a seizure disorderwell controlled on phenytoin. Which of the followingis

NOT

an expected possible contributing factor

inher

elevated risk for an open neural-tube

defect

Ethnicity

Medication exposure

Chromosome abnormality

None of the above

Slide9

gentic

Family history—multifactorial inheritance

MTHFR mutation—677C→T

Syndromes with autosomal recessive inheritance—

Meckel

Gruber, Roberts,

Joubert

Jarcho-Levin,

HARDE (hydrocephalus-agyria-retinal dysplasia-encephalocele)Aneuploidy—trisomy 13 and 18, triploidyEnvironmental ExposuresDiabetes—hyperglycemiaHyperthermia—hot tub or sauna, fever (controversial)Medications—valproic acid, carbamazepine, coumadin,thalidomide,

efavirenz

Geographical—Ethnicity, Diet, and Other Factors

United Kingdom, India, China, Egypt, Mexico, Southern

Appalachian United States

Slide10

What is the recurrence risk for an open

neural-

tubedefect

after a couple has had one child born

with anencephaly

3% to 5%b.

10%c. 25%d. Unknown

Slide11

The recurrence risk is

approxi-mately

3 to 5 percent if a couple has previously had a child

with either

anencephaly or

spina

bifida, 5 percent if either parent was born with an NTD, and as high as 10 percent if a couple has two affected children. Importantly, almost 95 percent of NTDsdevelop in the absence of a family

history.Other risk factors for NTDs include hyperthermia, medi-cations

that disturb folic acid metabolism, and hyperglycemia from insulin-dependent diabetesPolymorphisms in the methylene tetrahydrofolate reductase gene, which leads to impaired homocysteine and folate metabolism, have been asso-ciated with increased risk for anencephaly and spina bifida, aswell

as for cardiac malformations (

Aneji

, 2012;

Harisha

2010;Munoz

, 2007; Yin, 2012)

Slide12

Four-milligram folic acid supplementation

beforeconception

and in the first trimester of

pregnancywould

be most indicated in which of the

following scenarios

a. Maternal pregestational diabetesb. A personal history of open neural-tube defectc. Maternal valproic acid use for seizure disorderd. Maternal paroxetine use for depression

Slide13

Most women at increased risk for NTDs benefit from 4

mg folic

acid taken daily before conception and through the

first trimester

. This is particularly important if a woman has one

or more

prior affected children or if either the pregnant

woman or her partner has such a defect. Folic acid supplementation may not decrease the risk for NTDs in those with valproic

acid exposure, pregestational diabetes, first-trimester fever or

hot tub exposure, or defects associated with a genetic syndrome (American College of Obstetricians and Gynecologists, 2013b

Slide14

Which of the following maternal factors does

not affect

the maternal serum alpha fetoprotein (AFP

) multiples

of the median calculation

Race

b. Parity

c. Weightd. Gestational age

Slide15

1. Maternal weight—The AFP concentration is adjusted

forthe

maternal volume of distribution.

2. Gestational age—The maternal serum

concentrationincreases

by approximately 15 percent per week duringthe second trimester (Knight, 1992). In general, the MoM should be recalculated if the biparietal diameter differs

fromthe stated gestational age by more than 1 week.

3. Race/ethnicity—African American women have at least10-percent higher serum AFP concentrations but are at lower risk for fetal NTDs.4. Diabetes—Serum levels may be 10 to 20 percent lower inwomen with insulin-treated diabetes, despite a three- to fourfold increased risk for NTDs (Greene, 1988; Huttly, 2004). There is controversy whether sremains necessary or if results should apply to all types of diabetes (Evans, 2002; Sancken

, 2001; Thornburg, 2008).

Multifetal

gestation—Higher screening threshold

values are

used in twin pregnancies (

Cuckle

, 1990). At

Parkland Hospital

, an AFP level is considered elevated in a twin

preg

nancy

if greater than 3.5

MoM

, but other laboratories

use4.0

or even 5.0

MoM

Slide16

Which of the following is

NOT

an indication

for

sonographic

evaluation of an elevated

maternal serum

AFP level result?a.

Determination of fetal sexb. Estimation of gestational agec. Determination of fetal numberd. Documentation of fetal viability

Slide17

Slide18

Your patient has a 1:100 risk for a fetal open

neuraltube

defect based on serum screening at 18 weeks’

gestation. She undergoes targeted

sonographic

examination, which documents a singleton fetus and

a marginal placenta previa. No fetal abnormalities

are detected. Following this examination, how

should she be counseled regarding her fetus’s risk for

having an open neural-tube defect?a. Reduced by 25%b. Reduced by 50%c. Reduced by 95%d.

Unchanged from the 1% risk

Slide19

More than 25 years ago,

Nicolaides

and colleagues (1986)

described frontal bone scalloping—the lemon sign, and ante-

rior

curvature of the cerebellum with effacement of the cisterna

magna—the banana sign—in second-trimester fetuses with

open spina bifida (Fig. 14-4). These investigators also frequentlynoted a small biparietal diameter and ventriculomegaly in suchcases. Watson and coworkers (1991) reported that 99 percent

of fetuses with open spina bifida had one or more of these find-ings.

Slide20

Multiple screening strategies exist to detect Down

syndrome during pregnancy. Which of the following

tests has the highest detection rate for Down

syndrome?

Maternal serum AFP

Integrated screening

Quadruple marker testd. Combined first-trimester screening

Slide21

Slide22

A 38-year-old woman presents for

first-trimester screening

for Down syndrome at a gestational

age of

12 weeks and 1 day. The ultrasound image

below was

seen. What is the next step in evaluating

this finding?

a. Offer diagnostic prenatal testingb. Repeat the ultrasound measurement in 1 weekc. Complete the first-trimester screen and wait forher

numeric risk assessment

Offer a sequential test as it has a high

sensitivityfor

Down syndrome detection

Slide23

Slide24

Which of the following correctly identifies

the second-trimester

analyte

level abnormalities in

a pregnancy

at increased risk for Down syndrome?

Decreased MSAFP, increased

unconjugatedestriol

, increased inhibin, increased beta hCGb. Decreased MSAFP, decreased unconjugatedestriol, increased inhibin

, increased beta

hCG

Increased MSAFP, increased unconjugated

estriol,decreased

inhibin

, decreased beta

hCG

Decreased MSAFP, decreased

unconjugatedestriol

, decreased

inhibin

, increased beta

hCG

Slide25

Two

analytes

used for first-trimester aneuploidy screening

arehuman

chorionic gonadotropin—either intact or free β -

hCG

—and pregnancy-associated plasma protein A (PAPP-A). In casesof fetal Down syndrome, the first-trimester serum free β -hCGlevel is higher, approximately 2.0 MoM

, and the PAPP-Alevel is lower, approximately 0.5

MoM2nd trimester Pregnancies with fetal Down syndrome are character-ized by lower aternal serum AFP levels—approximately0.7 MoM, higher hCG levels—approximately 2.0 MoM,

andlower

unconjugated

estriol

levels—approximately 0.8

MoM

(

Merkatz

, 1984; Wald, 1988). Levels of a fourth marker—

dimeric

inhibin

alph

—are

ele

vated

in Down syndrome, with an average value of 1.8

MoM

(Spencer

, 1996). The addition of

dimeric

inhibin

to the

otherthree

markers is the quadruple or e quad test, which has a

trisomy21

detection rate of approximately 80 percent at a

false-

positiverate

of 5 percent

Slide26

Slide27

A 25-year-old

primigravida

from China has a

Downsyndrome

risk of 1:5000 based on her

first-

trimesterscreening results. The finding shown is noted duringa routine sonographic examination performed at17 weeks’ gestation. How should she be

counseledregarding this finding?

a. Schedule a fetal echocardiogram at 22 weeks’gestationb. Offer an amniocentesis since she is nowconsidered “high-risk”

Inform her that this finding is seen in up to 30%

of fetuses of Asian descent

Inform her that her Down syndrome risk has

now increased from 1 in 5000 to 1 in 500

Slide28

Second-Trimester

Sonographic

Markers

or “Soft Signs” Associated with Down

Syndrome Fetuses

Slide29

An echogenic

intracardiac

focus (EIF) is a focal papillary

mus-cle

calcification that is neither a structural nor functional

car-

diac abnormality. It is usually left-sided (Fig. 14-6B). An EIFis present in approximately 4 percent of fetuses, but it may befound in up to 30 percent of Asian individuals (Shipp, 2000).As an isolated finding, an EIF approximately doubles the

riskfor fetal Down syndrome (.

Particularly if bilat-eral, they are also common with trisomy 13 (Nyberg, 2001)

Slide30

Which of the following fetal conditions or events

NOT

associated with the finding of echogenic

bowel during

a second-trimester

sonographic

examination?

a. Down syndrome

b. Cystic fibrosisc. Toxoplasmosis infectiond. Intraamniotic hemorrhage

Slide31

Echogenic fetal bowel appears as bright as bone and is seen in

lapproximately

0.5 percent of pregnancies (Fig. 14-6D).

Althoughj

typically associated with normal outcomes, it increases the risk

for Down syndrome approximately

sixfold (see Table 14-8).Echogenic bowel may represent small amounts of swallowedblood and may be seen in the setting of AFP level elevation(p. 287). It has also been associated with fetal cytomegalovirusinfection and cystic fibrosis—representing inspissated

meconiumin the latter.

Slide32

Which of the following skeletal findings during

sonographic

examination suggest an increased

fetal risk

for Down syndrome?

Observed:expected

femur ratio ≤ .90

b. Observed:expected

humerus ratio ≤ .90c. Femur length:abdominal circumference ratio < .20d. Observed:expected

biparietal

diameter ratio < .89

Slide33

The femur and

humerus

are slightly shorter in Down

syn-drome

fetuses, although the femur length to abdominal

cir-cumference

(FL/AC) ratio is generally within the normal rangein the second trimester. The femur is considered “short” forDown syndrome screening if it measures ≤ 90 percent of thatexpected. The expected femur length is that which

correlates with the measured biparietal diameter (Benacerraf, 1987

Slide34

What is the appropriate screening test for

hemoglobinopathies

in patients of African descent?

Complete blood count

Peripheral blood smear

Hemoglobin electrophoresisd.

Hemoglobin S mutation analysis

Slide35

Slide36

There is an increased pregnancy loss rate following

amniocentesis in all

EXCEPT

which of the

following conditions?

Twin gestation

Maternal BMI ≥ 40 kg/m2

c. Transplacental puncture with needled. All of the above

Slide37

Slide38

A 40-year-old infertility patient underwent an

amniocentesis at 17 weeks’ gestation. She calls

1 day later and reports that she is leaking

amnionic

fluid. What should she be told about this

postamniocentesis

complication?

Fetal survival is > 90%.

b. The risk of fetal death is 25%.c. The risk for chorioamnionitis is 2%.d. Fluid leakage occurs in approximately 10% ofpatients.

Slide39

Slide40

Early amniocentesis is defined as amniocentesis

that is performed during which of the following

gestational age windows?

9–11 weeks

11–14 weeks

12–15 weeks

d. 14–16 weeks

Slide41

Slide42

A woman undergoes a chorionic villus sampling

(CVS) at 11 weeks’ gestation. The result shows two

cell lines—46,XY and 47,XY,+ 21. What is the

appropriate next step?

Repeat CVS at 13 weeks’ gestation

Plan no further evaluation or treatment

Offer amniocentesis for clarification of resultsd. Provide the patient with appropriate informationregarding Down syndrome

Slide43

Slide44

Chorionic villus sampling has been associated with

limb reduction defects under what condition?

Multiple needle passes are made.

Performed at a gestational age < 10 weeks

Performed using a

transabdominal

approachd. Larger volumes of chorionic villi are sampled.

Slide45

Slide46

Fetal blood sampling performed at the placental

insertion site is associated with which of the

following?

Shorter procedure duration

Increased pregnancy loss rate

Increased procedure success rate

d. Decreased maternal blood contamination

Slide47

Slide48

Which of the following statements correctly

describes polar body analysis when used for

preimplantation

genetic testing?

It involves sampling one cell of the embryo on

day 3.

It is associated with decreased pregnancy success

rates.c. It can be used to determine paternally inheritedgenetic disorders.d. None of the above

Slide49

Slide50

Preimplantation

genetic diagnosis may be used for

which of the following scenarios?

Determine fetal gender

Diagnose single gene mutations

Human leukocyte antigen (HLA) typingd.

All of the above

Slide51

Slide52

Which of the following is

NOT

a limitation of

preimplantation

genetic screening using fluorescence

in situ hybridization?

The result may not reflect the embryonic

karyotype.b.

Genomic hybridization arrays have a high failurerate.c. Mosaicism is common in cleavage-stage embryoblastomeres.d. Pregnancy rates are lower followingpreimplantation

genetic screening

Slide53

Slide54

Slide55

Slide56

Slide57

Slide58

Slide59

Slide60

Slide61

Slide62

Slide63